USWEX EA/OEA Vol. 1 - Govsupport.us

UNDERSEA WARFARE EXERCISE (USWEX) 

PROGRAMMATIC ENVIRONMENTAL ASSESSMENT/ 

OVERSEAS ENVIRONMENTAL ASSESSMENT (EA/OEA) 

Volume 1 of 2 

October 2007

Executive Summary 

EXECUTIVE SUMMARY 

Introduction 

A Programmatic Environmental Assessment (EA)/Overseas EA (OEA) was prepared by the Department 

of the Navy in compliance with the National Environmental Policy Act (NEPA) of 1969 (42 United 

States Code § 4321 et seq.); the Council on Environmental Quality Regulations for Implementing the 

Procedural Provisions of NEPA (Title 40 Code of Federal Regulations (CFR) §§ 1500-1508 (2005)); 

Department of the Navy Procedures for Implementing NEPA (32 CFR § 775 (2005)); and Executive 

Order (EO) 12114, Environmental Effects Abroad of Major Federal Actions. The NEPA process ensures 

that environmental impacts of proposed major federal actions are considered in the decision-making 

process. EO 12114 requires environmental consideration for actions that may significantly harm the 

environment of the global commons (e.g., environment outside U.S. Territorial Waters). That EA/OEA 

satisfied the requirements of both NEPA and EO 12114. 

Based on that analysis, a Finding of No Significant Impact (FONSI) was issued on 24 January 2007. Two 

Undersea Warfare Exercises (USWEXs) have been completed since that FONSI was signed. There have 

been no identified significant impacts resulting from those exercises, there has been no identified 

significant impact from USWEX training that has taken place since 2005, and there have been no 

identified significant impacts during the approximate 40-year history of similar ASW training in the 

Hawaii Range Complex (HRC). 

Subsequent to the issuance of the FONSI for the USWEX action, the Navy determined that it should 

clarify and revise the sections of the document dealing with the Coastal Zone Management Act (CZMA) 

and make other clarifications and revisions as appropriate. This would also provide an opportunity to 

request comments from the public on this ongoing action and to reconsider the FONSI in light of those 

comments. This EA/OEA for the remaining USWEXs through January 2009 contains revised analysis of 

the potential environmental impacts of the exercises based upon the public comments received. 

Background 

USWEX is an assessment based Anti-Submarine Warfare (ASW) exercise conducted by the U.S. Navy’s 

Expeditionary Strike Groups (ESG) and Carrier Strike Groups (CSG) and while in transit from the west 

coast of the United States to the Western Pacific Ocean. The ESG is a relatively new naval organizational 

structure, having been established in 2003 as part of ongoing transformation processes in the Department 

of the Navy. The ESG includes surface combatant ships, submarines, and an amphibious ready group. 

The CSG organizational structure likewise reflects enhanced operational capabilities for configurations 

formerly known as carrier battle groups. The CSG typically consists of an aircraft carrier, Aegis-class 

cruisers, other surface combatants, and attack submarines. Larger naval formations, such as a two-carrier 

formation—a Carrier Strike Force—are possible. 

Along with the assessment goal, there is significant training value in USWEX, as training is inherent in 

all at-sea exercises. Training may be considered a subset of the USWEX efforts designed to assess our 

ability to conduct ASW in the most realistic environment, against the level of threat expected in order to 

effect changes to both training and capabilities, (e.g., equipment, tactics, and changes to size and 

composition of the Strike Groups and manning). While other training exercises occur during the 

remainder of the deployment, USWEXs are conducted shortly after deployment to ensure the Strike 

October 2007 USWEX EA/OEA es-1


Groups are fully capable of conducting strike warfare while defending themselves against submarines. 

The USWEX assessment allows additional crew ASW training opportunity to occur at this junction 

because skill sets diminish over time and it is necessary to ensure the Strike Group maintains and 

improves upon critical ASW skill sets. 

The USWEX assessment provides the Commander, U.S. Pacific Fleet, the ability to identify future ASW 

requirements. The USWEX assessment efforts have been instrumental and directly responsible for a 

significant increase in Navy ASW investments and positive changes to our tactics, thereby improving our 

ASW capabilities. Not assessing the ASW ability of a Strike Group to succeed at the highest level 

possible when there is the opportunity to do so would present an overwhelming national security concern, 

as the failure to do so could result in significant adverse results in combat, including the loss of ships and 

life. 

USWEX assessment and training is best undertaken in Hawaii due to its central location in the Pacific, the 

presence of the instrumented tracking ranges at Pacific Missile Range Facility, the presence of various 

Department of Defense-controlled beaches enabling amphibious landing training while conducting ASW, 

the ability for fixed-wing aircraft sorties to the Pohakuloa Training Area (island of Hawaii) and rotary 

aircraft to fly sorties to Kaula while their Strike Group conducts ASW, the presence of submarines 

homeported at Pearl Harbor (which can serve as an opposition force), and the vast size of the HRC where 

a Strike Group can train in a realistic manner unfettered by artificial and unrealistic exercise boundaries. 

The deployment of naval forces is determined by the combatant Commanders-in-Chief based on the 

Global Naval Force Presence Policy (GNFPP). The GNFPP is the process by which naval forces are 

allocated. In order to meet operational requirements, most notably for Strike Group deployments, the 

GNFPP addresses where and when Strike Groups with embarked Marine Air-Ground Task Forces are 

deployed throughout the world. The dynamic requirements of national security, including the Global War 

on Terrorism and other operational commitments, affect the deployment of naval forces. As a result, the 

GNFPP is not a fixed deployment schedule but is flexible and often changes to meet the Nation’s security 

needs. As these changing operational needs impact the deployment schedules of naval forces, they 

subsequently affect the training cycles required to ensure that these forces are adequately trained to 

conduct assigned missions. As an example, Strike Group training dates cannot be fixed to a month or 

even a season on a recurring annual basis. Real-world contingencies drive the training schedule in 

relation to when the Strike Group is required to be in a Unified Commander’s area of responsibility. To 

meet this readiness challenge and the demands of the GNFPP, the U.S. Navy executes its Fleet Response 

Plan (FRP). The FRP calls for the capability to deploy or surge Strike Groups in a very short time. 

The deployment training cycle for the Strike Groups comprises pre-deployment training and certification, 

deployment, and post-deployment maintenance. The USWEX is an important component of the training 

and deployment of naval forces organized into ESGs and CSGs. The objective of the exercise is to 

enhance the interoperability and proficiency of naval surface, subsurface, and air forces to counter 

submarine threats in the context of littoral operations. The training environment of the USWEX 

replicates expected operating conditions as realistically as practicable. USWEX exercises also 

demonstrate the ability of a naval force to identify a potential threat, communicate effectively and 

continue to operate in different scenarios. Based on the U.S. Navy’s FRP, which governs deployment 

training cycles and global deployment of naval forces, the U.S. Pacific Fleet anticipates the need to 

conduct between four and six USWEXs annually. 

es-2 USWEX EA/OEA October 2007


USWEX Activities 

All USWEX activities would occur within the HRC, which encompasses offshore, near shore, and 

onshore areas located on or around the major islands of the Hawaiian Island chain. 

ASW training conducted during a USWEX utilizes ships, submarines, aircraft, non-explosive exercise 

weapons, and other training systems and devices. During a typical USWEX, embarked aircraft will also 

be conducting training prior to arriving in the western Pacific Ocean. Fixed-wing aircraft will fly sorties 

to Pohakuloa Training Area on the island of Hawaii, and rotary aircraft will fly sorties to Kaula located 

off the coast of Kauai. Aircraft will utilize these live ranges to drop live or inert rounds. During an ESG 

USWEX, amphibious forces would utilize the beaches at Pacific Missile Range Facility or at Marine 

Corps Training Area Bellows to conduct amphibious landings. Table ES-1 includes a summary of the 

exercises to be conducted during a USWEX. 

Table ES-1. Exercises Conducted During USWEX 

Exercise 

Anti-Submarine 

Warfare Exercise 

(ASWEX) 

Gunnery Exercise 

(GUNEX) 

Air Combat Maneuvers 

(ACM) 

Air-to-Surface 

Missile/Bomb Exercise 

(ASMEX) 

Air-to-Ground Strike 

Warfare Exercise 

(STWEX) 

Amphibious Exercise 

(AMPHIBEX) 

Description 

As a combined force, submarines, surface ships, and aircraft will conduct ASW 

against opposition submarine targets. The primary event involves from one to five 

surface ships equipped with sonar, with one or more helicopters, and P-3 aircraft 

searching for one or more submarines. 

GUNEX operations are conducted by rotary-wing aircraft against stationary targets 

(Floating at Sea Target and smoke buoy). 

ACM includes Basic Fighter Maneuvers where aircraft engage in offensive and 

defensive maneuvering against each other. 

An ASMEX provides training for U.S. Navy and U.S. Marine Corps tactical 

aircrews in air-to-surface missile firing; conventional ordnance delivery (including 

bombing, gunnery, and rocketry); and precision-guided munitions firing at sea. 

The STWEX exercise provides training for U.S. Navy and U.S. Marine Corps 

fighter and attack aircraft crews in air-to-ground missile firing, conventional 

ordnance delivery (including bombing, gunnery, and rocketry), and precisionguided 

munitions firing. 

An AMPHIBEX involves the movement of Marine Corps combat and support 

forces from U.S. Navy ships at sea to an objective or an operations area ashore. 

Methodology 

The EA/OEA includes an analysis of Alternative 1, Alternative 2, and the No-Action Alternative. The 

analysis in this EA/OEA covers the remainder of the 2-year time period from January 2007 through 

January 2009. Alternative 1 is designed to meet the maximum expected U.S. Navy and Department of 

Defense (DoD) current and near-term operational training requirements based on known and expected 

force structure. This Alternative analyzes four CSG USWEXs and two ESG USWEXs per year occurring 

in Hawaii. Alternative 2 is designed to meet the typical expected U.S. Navy and DoD current and nearterm 

operational training requirements based on known and expected force structure. This Alternative 

analyzes three CSG USWEXs and one ESG USWEX per year occurring in Hawaii. 



Under the No-Action Alternative, individual training events that compose a USWEX would continue to 

occur; however, they would not be consolidated into a coordinated training event. The potential impacts 

of the No-Action Alternative would not be significant. The training events would be analyzed 

individually, with the events occurring on an as-needed basis. However, conducting individual exercises 

would not meet the training objectives for deploying or deployable Strike Groups. Therefore, 

implementation of the No-Action Alternative is fundamentally inconsistent with directives governing the 

training of naval forces and the responsibilities vested in the Department of the Navy for readiness of 

naval forces, including the area of undersea warfare. 

Consistent with Council on Environmental Quality regulations, the scope of the analysis presented in this 

Programmatic EA was defined by the range of potential environmental impacts that could result from 

implementation of the Proposed Action and No-Action Alternative. Only those resources that have a 

potential for impacts were included in the Programmatic EA analysis to provide the decision maker with 

sufficient evidence and analysis for evaluation of the potential effects of the action. 

Initial screening of existing environmental documentation determined that USWEX would have no 

significant impact on air quality, geology and soils, hazardous materials and waste, socioeconomics, and 

water resources. Air quality impacts would be limited to temporary, short-term vehicle emissions from 

vehicles used during an Amphibious Exercise (AMPHIBEX). These emissions would be minor and are 

considered mobile sources. Geology and soils impacts would be limited to short-term minor disturbance 

of beach sand along existing AMPHIBEX access routes. Movement from the beach would also result in 

minor, short-term disturbance to pre-defined access routes. Ordnance impacts during a Gunnery Exercise 

(GUNEX) and Air-to-Ground Strike Warfare Exercise (STWEX) would result in localized soil 

disturbance within an existing impact area. Any hazardous materials used and waste generated would be 

managed in accordance with applicable State and federal requirements. The USWEX Letter of 

Instruction defines specific responsibilities regarding implementing the procedures to meet these 

requirements for managing hazardous waste generated during a USWEX. There is very little opportunity 

for economic interaction during a USWEX. In-port expenditures by transient military personnel either 

before or after a USWEX would have a minor positive direct effect on the local community. Water 

resources would not be impacted by AMPHIBEX activities. Ordnance impacts from GUNEX and 

STWEX would not significantly impact the minimal water resources at the USWEX locations. 

The analysis conducted in the USWEX EA/OEA focused on the following resources: airspace, biological 

resources, cultural resources, land use, noise, and safety and health. For biological resources the USWEX 

EA/OEA includes analysis related to hull-mounted mid-frequency active tactical sonar. Marine mammal 

research and other scientific information has led to the ability to quantitatively assess marine mammal 

exposure levels, related to harassment as defined in the 2004 amendments to the Marine Mammal 

Protection Act (MMPA) amendment relating to military readiness activities. The USWEX EA/OEA 

provides an analysis of exposure of marine mammals to hull-mounted mid-frequency active tactical sonar 

during the USWEX training events proposed for both Alternatives 1 and 2. 

Results 

Airspace—Use of rotary and fixed wing aircraft and missiles will be within special use airspace, such as 

Warning Areas and Restricted airspace. No new special use airspace proposal or any modification to the 

existing special use airspace is contemplated for the Proposed Action. 



Biological Resources—Impacts to biological resources will not be significant. Installation Natural 

Resource Management Plans have been prepared for land ranges to help identify and manage areas with 

sensitive habitat. Standard Operating Procedures and the USWEX Letter of Instruction also include 

specific requirements for avoiding sensitive habitat areas. Established protective measures will be 

followed to protect marine mammals and federally listed species during USWEX training events. The 

EA/OEA analyzes mid-frequency active tactical sonar use associated with the USWEX. The EA/OEA 

documents an acoustic exposure effects-analysis on marine mammals that may be affected by the 

USWEX training events and use of mid-frequency active tactical sonar. 

U.S. Navy modeling shows potential exposures that could lead to Level B harassment under the MMPA. 

However, effects to marine mammal species or stocks from USWEX training events would be negligible. 

The use of mid-frequency active tactical sonar in ASW training has been occurring in the Hawaiian 

Islands for approximately 40 years using the same basic equipment with no direct evidence of harm to 

marine mammals. The USWEX is an example of ASW training using mid-frequency active tactical 

sonar. After decades of ASW training in the Hawaiian Islands, there is no direct evidence of marine 

mammal strandings having occurred in the timeframe of those events or otherwise associated with any of 

those events, so it is extremely unlikely that any significant behavioral response will result from the 

interaction of marine mammals and the use of sonar during USWEX. There are no predicted marine 

mammal sonar exposures that would result in injury or mortality. In accordance with the MMPA, the 

Deputy Secretary of Defense invoked a National Defense Exemption (NDE) on January 23, 2007, that 

requires all ships, submarines, and aircraft employing mid-frequency active sonar to adhere to marine 

mammal mitigation measures during major exercises or within established ranges and Operating Areas. In 

order to ensure full compliance with the MMPA during USWEX, all ships, submarines, and helicopters 

engaged in mid-frequency active sonar activities will adhere to the 29 mitigation measures identified in 

the MMPA National Defense Exemption signed on January 23, 2007 and included in Section 5.1.2 of this 

EA/OEA. The mandatory NDE protective measures were developed with and fully supported by the 

National Marine Fisheries Service (NMFS). Therefore, Navy has determined that there will be no 

significant impacts to marine mammals as a result of the conduct of USWEX exercises under alternative 

1. 

The Navy is preparing an Environmental Impact Statement (EIS) for the Hawaiian Range Complex 

(HRC). In a draft EIS (DEIS) provided to the public for review and comment, the Navy and NMFS (as a 

cooperating agency) solicited comment on a "dose-function" modeling methodology for assessing the 

probability of marine mammals being behaviorally harassed by potential exposure to mid-frequency 

active sonar. Because Navy has not yet issued a Record of Decision for the Hawaii Range Complex EIS, 

and NMFS has not promulgated the use of the dose-function model through its rule-making process, the 

USWEX EA/OEA uses the existing energy flux density methodology for assessing behavioral and 

physiological effects. 

Because the proposed USWEX ASW training events may affect endangered species, the U.S. Navy 

consulted with NMFS under Section 7 of the ESA and received a Biological Opinion and Incidental Take 

Statement. The resultant conclusion from the NMFS Biological Opinion is as follows: “After reviewing 

the current status of the endangered fin whale, humpback whale, sei whale, and sperm whale, the 

environmental baseline for the action area, the effects of the proposed Undersea Warfare Exercises, and 

the cumulative effects, it is NMFS’ biological opinion that the Navy’s proposed Undersea Warfare 

Exercises in waters off the State of Hawaii from January 2007 through January 2009 may adversely 

affect, but is not likely to jeopardize the continued existence of these threatened and endangered species 



under NMFS jurisdiction.” The Reasonable and Prudent Measures and Terms and Conditions required 

under the Incidental Take Statement (included in Section 5.1.4 of this EA/OEA) are identified to ensure 

Navy’s compliance under ESA during USWEX. As provided in 50 CFR 402.16, reinitiation of formal 

consultation is required where discretionary Federal agency involvement or control over the action has 

been retained (or is authorized by law) and if: (1) the amount or extent of incidental take is exceeded; (2) 

new information reveals effects of the agency action that may affect listed species or critical habitat in a 

manner or to an extent not considered in the biological opinion; (3) the agency action is subsequently 

modified in a manner that causes an effect to the listed species or critical habitat not considered in the 

biological opinion; or (4) a new species is listed or critical habitat designated that may be affected by the 

action. After examining all of these criteria, Navy has determined the reinitiation of consultation is not 

required. 

Cultural Resources—Impacts to cultural resources are not anticipated since known sites will be avoided. 

Integrated Cultural Resource Management Plans and Standard Operating Procedures identify and outline 

methods for avoiding cultural resource areas. All training exercises are designed to avoid sensitive 

cultural areas. Ordnance impacts on land are limited to designated impact areas. 

Land Use—Only minor, temporary impacts will occur from closing various beaches to public use for 

several hours to accommodate an AMPHIBEX. Closings are normal, ongoing occurrences at the various 

installations. Proposed USWEX activities have been determined to be compatible with current land uses 

(i.e., weapons impacting in designated impact areas) and no affects to the installations or adjacent land 

uses are anticipated. 

Noise—No significant impacts have been identified. Exercise areas are located away from sensitive 

receptors on existing installation and ranges designated for the proposed noise generating activity. 

Safety and Health—Impacts to the health and safety of workers or the public are not expected. Specific 

safety plans are developed to ensure that each hazardous operation is in compliance with applicable 

policy and regulations and to ensure that the general public and range personnel and assets are provided 

an acceptable level of safety. 

As noted previously, modeling was undertaken to assess potential effects by estimating the numbers of 

marine mammals that could be affected by the activities associated with the use of hull-mounted midfrequency 

active tactical sonar during USWEX. The results from that modeling do not represent a 

guarantee of the interaction of sound and mammals since there are factors that will occur relative to the 

modeled parameters, such as the mitigating effect of standard operating procedures serving as protective 

measures. These procedures include measures such as decreasing the source level and then shutting down 

active tactical sonar operations when marine mammals are encountered in the vicinity of a training event. 

Although these protective measures are standard operating procedures, their use is also reinforced through 

promulgation of an Environmental Annex to the Letter of Instruction issued to USWEX participants. 

U.S. Navy ships have a number of NMFS-approved procedures in place to detect marine mammals in 

their vicinity. While conducting the exercise, U.S. Navy ships always have two, although usually more, 

personnel on watch serving as lookouts. In addition to the qualified lookouts, the bridge team is present 

that at a minimum also includes an Officer of the Deck and one Junior Officer of the Deck whose 

responsibilities also include observing the waters in the vicinity of the ship. At night, personnel engaged 

in ASW events may also employ the use of night vision goggles and infra-red detectors, as appropriate, 

which can also aid in the detection of marine mammals. Passive acoustic detection of vocalizing marine 



mammals is also used to alert bridge lookouts to the potential presence of marine mammals in the 

vicinity. 

The federally listed species that may occur in the geographic area of the Proposed Action include the 

North Pacific right whale (Eubalaena japonica), the humpback whale (Megaptera novaeangliae), the sei 

whale (Balaenoptera borealis), the fin whale (Balaenoptera physalus), the blue whale (Balaenoptera 

musculus), the sperm whale (Physeter macrocephalus), the Hawaiian monk seal (Monachus 

schauinslandi), the loggerhead sea turtle (Caretta caretta), the green sea turtle (Chelonia mydas), the 

hawksbill sea turtle (Eretmochelys imbricata), the leatherback sea turtle (Dermochelys coriacea), and the 

olive ridley sea turtle (Lepidochelys olivacea). However, based on the analysis within this EA/OEA the 

U.S. Navy concludes that the proposed USWEX activities “may affect,” as that term is interpreted under 

the Endangered Species Act, fin whales, sei whales, sperm whales, and humpback whales. As such, the 

U.S. Navy has consulted with the NMFS under Section 7 of the ESA. 

Without consideration of the current mandatory mitigation measures, acoustic effects modeling estimate 

on an annual basis: up to 3 incidents of sperm whale exposure and 49 incidents of humpback whale 

exposure to sonar signals that exceed a Temporary Threshold Shift harassment threshold of 195 dB re 1 

µPa 2 -s EL; approximately 23 incidents of sperm whale exposure and 423 incidents of humpback whale 

exposure to sonar signals above 190 dB re 1 µPa 2 -s EL; and approximately 905 incidents of sperm whale 

exposure, 48 incidents of fin whale exposure, 21 incidents of sei whale exposure, and 10,273 incidents of 

humpback whale exposure to sonar signals above 173 dB re 1 µPa 2 -s EL. The modeling also indicates 

that no marine mammals would be exposed to the MMPA Permanent Threshold Shift injury threshold of 

215 dB re 1 μPa 2 -s. 

Conclusions 

As summarized in the preceding paragraphs, the Navy analyzed the Proposed Action for potential impacts 

to the affected environment. Based on the analysis presented in this EA/OEA, no significant impacts on 

any of the affected environment resource areas will occur as a result of implementing the Proposed Action 

for Alternative 1 or Alternative 2. 

This EA/OEA therefore concludes that USWEX will result in: 

• No significant impacts in accordance with NEPA. 

• No significant harm to resources in the global commons under EO 12114. 

• No significant impacts to cultural resources. Consistent with 36 CFR 800.4(a)(1) and 

800.16(y), the U.S. Navy has determined that USWEX does not constitute an undertaking in the 

sense that no new activities are planned. Instead, it is simply the coordination of ongoing 

training events that have been previously conducted and would be combined into one exercise 

for USWEX. 

• No destruction or adverse modification of any critical habitat in accordance with the ESA. 

USWEX training events may affect sperm whales, fin whales, sei whales, and humpback 

whales. The U.S. Navy consulted with NMFS under Section 7 of the ESA and received a 

Biological Opinion and Incidental Take Statement that concluded the level of anticipated takes 

would not result in jeopardy to any federally listed species. 



• A potential for Level B harassment of marine mammals. However, effects to marine mammal 

species or stocks from USWEX training events would be negligible. The use of mid-frequency 

active sonar in ASW training has been occurring in the Hawaiian Islands for approximately 40 

years using the same basic equipment with no direct evidence of harm to marine mammals. The 

USWEX is an example of ASW training utilizing mid-frequency active tactical sonar. Based on 

decades of ASW training having occurred in the Hawaiian Islands, and no direct evidence of 

marine mammal strandings having occurred in the timeframe of those events or otherwise 

associated with any of those events, it is extremely unlikely that any significant behavioral 

response will result from the interaction of marine mammals and the use of sonar during 

USWEX. Due to the fact that the model predicts Level B exposures of marine mammals in 

order to ensure full compliance with the MMPA during USWEX, all ships, submarines and 

helicopters engaged in mid-frequency active sonar activities will adhere to the mitigation 

measures identified in the NDE signed on January 23, 2007, and included in Section 5.1.2 of 

this EA/OEA. 

• A may affect determination for federally listed species. The U.S. Navy consulted with NMFS 

under Section 7 of the ESA and received a Biological Opinion and Incidental Take Statement. 

The NMFS Biological Opinion concluded that USWEX may adversely affect, but is not likely 

to jeopardize the continued existence of threatened and endangered species under NMFS 

jurisdiction. The Reasonable and Prudent Measures and Terms and Conditions required under 

the Incidental Take Statement (included in Section 5.1.4 of this EA/OEA) are identified to 

ensure Navy’s compliance under ESA during USWEX. 

• No adverse impact to Essential Fish Habitat in accordance with the Magnuson-Stevens Fishery 

Conservation and Management Act. 

• No effects to Hawaii’s coastal uses or resources under the Coastal Zone Management Act. 


Table of Contents 

UNDERSEA WARFARE EXERCISE 

PROGRAMMATIC ENVIRONMENTAL ASSESSMENT/ 

OVERSEAS ENVIRONMENTAL ASSESSMENT (EA/OEA) 

TABLE OF CONTENTS 

EXECUTIVE SUMMARY ...................................................................................................................... es-1 

ACRONYMS AND ABBREVIATIONS ................................................................................................ ac-1 

1.0 PURPOSE AND NEED FOR PROPOSED ACTION ........................................................................ 1-1 

1.1 Introduction ................................................................................................................................ 1-1 

1.2 Background ................................................................................................................................ 1-1 

1.3 Overview of Hawaii Range Complex ........................................................................................ 1-3 

1.4 Scope and Content of the EA/OEA ............................................................................................ 1-5 

1.5 Purpose and Need ....................................................................................................................... 1-6 

1.6 Related Environmental Documents ............................................................................................ 1-6 

2.0 DESCRIPTION OF PROPOSED ACTION AND ALTERNATIVES............................................... 2-1 

2.1 Description of the Hawaiian Islands Operating Area ................................................................. 2-1 

2.2 Proposed Action ......................................................................................................................... 2-3 

2.2.1 Active Acoustic Devices Utilized During the USWEX ................................................ 2-5 

2.2.2 Non-ASW Events Occurring During a USWEX ........................................................... 2-8 

2.2.2.1 Air-to-Surface Gunnery Exercise (GUNEX) .................................................... 2-8 

2.2.2.2 Air Combat Maneuvers (ACM) ........................................................................ 2-8 

2.2.2.3 Air-to-Surface Missile/Bomb Exercise (ASMEX) ........................................... 2-8 

2.2.2.4 Air-to-Ground Strike Warfare Exercise (STWEX) .......................................... 2-9 

2.2.2.5 Amphibious Exercise (AMPHIBEX) ............................................................... 2-9 

2.3 Alternatives Analysis ............................................................................................................... 2-10 

2.3.1 Evaluation Factors/Screening Criteria ......................................................................... 2-10 

2.3.2 Alternatives Eliminated From Further Consideration ................................................. 2-10 

2.3.2.1 Locations other than Hawaii ........................................................................... 2-10 

2.3.2.2 Computer Simulation Training ....................................................................... 2-11 

2.4 Alternatives For Implementing the Proposed Action ............................................................... 2-11 

2.4.1 Alternative 1—Six USWEXs Conducted per Year ..................................................... 2-11 

2.4.2 Alternative 2—Four USWEXs Conducted per Year ................................................... 2-12 

2.5 No-Action Alternative .............................................................................................................. 2-12 

3.0 AFFECTED ENVIRONMENT .......................................................................................................... 3-1 

3.1 Pacific Missile Range Facility (PMRF), Kauai .......................................................................... 3-2 

3.1.1 Airspace—PMRF, Kauai ............................................................................................... 3-2 

3.1.2 Biological Resources—PMRF, Kauai ........................................................................... 3-5 

3.1.3 Cultural Resources—PMRF, Kauai ............................................................................... 3-7 

3.1.4 Safety and Health—PMRF, Kauai ................................................................................ 3-7 

3.2 Marine Corps Training Area Bellows (MCTAB) ...................................................................... 3-7 

3.2.1 Airspace—MCTAB, Oahu ............................................................................................ 3-9 

3.2.2 Biological Resources—MCTAB, Oahu ........................................................................ 3-9 

3.2.3 Cultural Resources—MCTAB, Oahu .......................................................................... 3-10 

3.2.4 Land Use—MCTAB, Oahu ......................................................................................... 3-10 

3.2.5 Noise—MCTAB, Oahu ............................................................................................... 3-11 

October 2007 USWEX EA/OEA i


3.3 Kaula ........................................................................................................................................ 3-12 

3.3.1 Airspace—Kaula.......................................................................................................... 3-12 

3.3.2 Biological Resources—Kaula ...................................................................................... 3-12 

3.3.3 Cultural Resources—Kaula ......................................................................................... 3-13 

3.3.4 Safety and Health—Kaula ........................................................................................... 3-13 

3.4 Pohakuloa Training Area (PTA), Hawaii ................................................................................. 3-14 

3.4.1 Airspace—PTA, Hawaii .............................................................................................. 3-14 

3.4.2 Biological Resources—PTA, Hawaii .......................................................................... 3-16 

3.4.3 Cultural Resources—PTA, Hawaii .............................................................................. 3-16 

3.4.4 Noise—PTA, Hawaii ................................................................................................... 3-17 

3.4.5 Safety and Health—PTA, Hawaii ................................................................................ 3-17 

3.5 Ocean Area Hawaiian Islands .................................................................................................. 3-18 

3.5.1 Airspace—Ocean Area, Hawaiian Islands ................................................................... 3-18 

3.5.2 Biological Resources—Ocean Area, Hawaiian Islands ............................................... 3-19 

3.5.2.1 Benthic Invertebrates ...................................................................................... 3-20 

3.5.2.2 Fish ................................................................................................................. 3-20 

3.5.2.3 Seabirds .......................................................................................................... 3-22 

3.5.2.4 Marine Mammals ............................................................................................ 3-22 

3.5.2.5 Marine Mammal Occurrence .......................................................................... 3-22 

3.5.2.5.1 Endangered Cetaceans ................................................................... 3-24 

3.5.2.5.2 Endangered Pinniped ..................................................................... 3-27 

3.5.2.5.3 Non-Endangered Cetaceans .......................................................... 3-28 

3.5.2.5.4 Non-Endangered Pinniped ............................................................ 3-33 

3.5.2.6 Threatened and Endangered Sea Turtles ........................................................ 3-34 

3.5.2.6.1 Green Turtle (Chelonia mydas) ..................................................... 3-34 

3.5.2.6.2 Hawksbill Turtle (Eretmochelys imbricata) .................................. 3-35 

3.5.2.6.3 Olive Ridley Turtle (Lepidochelys olivacea) ................................ 3-35 

3.5.2.6.4 Leatherback Turtle (Dermochelys coriacea) ................................. 3-36 

3.5.2.6.5 Loggerhead Turtle (Caretta caretta) ............................................. 3-37 

3.5.3 Safety and Health—Ocean Area, Hawaiian Islands .................................................... 3-38 

4.0 ENVIRONMENTAL CONSEQUENCES ......................................................................................... 4-1 

4.1 Alternative 1—Conduct Six USWEX Per Year ......................................................................... 4-1 

4.1.1 Pacific Missile Range Facility (PMRF), Kauai ............................................................. 4-1 

4.1.1.1 Airspace—PMRF—AMPHIBEX ..................................................................... 4-2 

4.1.1.2 Biological Resources—PMRF—AMPHIBEX ................................................. 4-2 

4.1.1.3 Cultural Resources—PMRF—AMPHIBEX .................................................... 4-3 

4.1.1.4 Safety and Health—PMRF—AMPHIBEX ...................................................... 4-3 

4.1.2 Marine Corps Training Area Bellows (MCTAB), Oahu ............................................... 4-3 

4.1.2.1 Airspace—MCTAB—AMPHIBEX ................................................................. 4-3 

4.1.2.2 Biological Resources—MCTAB—AMPHIBEX ............................................. 4-3 

4.1.2.3 Cultural Resources—MCTAB—AMPHIBEX ................................................. 4-4 

4.1.2.4 Land Use—MCTAB—AMPHIBEX ................................................................ 4-5 

4.1.2.5 Noise—MCTAB—AMPHIBEX ...................................................................... 4-5 

4.1.3 Kaula .............................................................................................................................. 4-5 

4.1.3.1 Airspace—Kaula—STWEX, GUNEX ............................................................. 4-5 

4.1.3.2 Biological Resources—Kaula—STWEX, GUNEX ......................................... 4-5 

4.1.3.3 Cultural Resources—Kaula—STWEX, GUNEX ............................................. 4-6 

4.1.3.4 Safety and Health—Kaula—STWEX, GUNEX .............................................. 4-7 

4.1.4 Pohakuloa Training Area (PTA), Hawaii ...................................................................... 4-7 

4.1.4.1 Airspace—PTA—STWEX ............................................................................... 4-7 

ii USWEX EA/OEA October 2007


4.1.4.2 Biological Resources—PTA—STWEX ........................................................... 4-7 

4.1.4.3 Cultural Resources—PTA—STWEX .............................................................. 4-8 

4.1.4.4 Noise—PTA—STWEX .................................................................................... 4-8 

4.1.4.5 Safety and Health—PTA—STWEX ................................................................ 4-8 

4.1.5 Ocean Area, Hawaiian Islands ....................................................................................... 4-9 

4.1.5.1 Airspace—Ocean Area, Hawaiian Islands—ASMEX, ASWEX, GUNEX ..... 4-9 

4.1.5.2 Biological Resources—Ocean Area, Hawaiian Islands—ASMEX, ASWEX, 

GUNEX ............................................................................................................ 4-9 

4.1.5.2.1 Acoustic Effects on Fish ............................................................... 4-11 

4.1.5.2.2 Acoustic Effects on Marine Mammals—Regulatory 

Framework .................................................................................... 4-12 

4.1.5.2.3 Indicators of Physiological Effects (PTS and TTS) ...................... 4-13 

4.1.5.2.4 Use of Energy Flux Density Level for Physiological Effect 

Thresholds ..................................................................................... 4-13 

4.1.5.2.5 Comparison to Surveillance Towed Array Sensor System Low 

Frequency Active Risk Functions ................................................. 4-14 

4.1.5.2.6 TTS and PTS Effect Thresholds .................................................... 4-14 

4.1.5.2.7 Behavioral Effects ......................................................................... 4-14 

4.1.5.2.8 Likelihood of Prolonged Exposure................................................ 4-17 

4.1.5.2.9 Likelihood of Masking .................................................................. 4-17 

4.1.5.2.10 Application of Effect Thresholds to Other Species ....................... 4-17 

4.1.5.2.11 Other Effects Considered .............................................................. 4-19 

4.1.5.2.12 Acoustic Effects Analysis Modeling ............................................. 4-20 

4.1.5.2.13 Acoustic Effects Criteria and Thresholds ...................................... 4-22 

4.1.5.2.14 Estimated Acoustic Effects on Marine Mammals (MMPA) ......... 4-23 

4.1.5.2.15 Melon-Headed Whale Stranding Event in July 2004 .................... 4-29 

4.1.5.2.16 Estimated Acoustic Effects on ESA Listed Species ...................... 4-30 

4.1.5.3 Safety and Health—Ocean Area, Hawaiian Islands—ASMEX, ASWEX, 

GUNEX .......................................................................................................... 4-35 

4.1.5.1 Environmental Justice ..................................................................................... 4-36 

4.2 Alternative 2—Conduct Four USWEX Per Year ..................................................................... 4-37 

4.2.1 Estimated Acoustic Effects on Marine Mammals (MMPA) ........................................ 4-37 

4.2.2 Estimated Acoustic Effects on ESA Listed Species .................................................... 4-41 

4.2.2.1 Cetaceans ........................................................................................................ 4-42 

4.3 No-Action Alternative .............................................................................................................. 4-43 

4.4 Cumulative Impacts .................................................................................................................. 4-43 

4.4.1 Landside Cumulative Impacts ..................................................................................... 4-43 

4.4.2 Open Ocean Activities with Potential Marine Species Impacts .................................. 4-46 

4.4.2.1 Commercial Fishing ....................................................................................... 4-47 

4.4.2.2 Ship Strikes ..................................................................................................... 4-47 

4.4.2.3 Anthropogenic Oceanic Noise ........................................................................ 4-48 

4.4.2.3.1 Anthropogenic Contributors to Oceanic Noise Levels .................. 4-49 

4.4.2.3.2 Operational Parameters of the Navy Mid-Frequency Active 

Sonar ............................................................................................. 4-51 

4.4.2.4 Environmental Contamination and Biotoxins................................................. 4-52 

4.4.2.4 Other U.S. Navy Training Activities in the Open Ocean ............................... 4-52 

4.4.3 Summary of Marine Mammal Cumulative Impacts .................................................... 4-53 

5.0 PROTECTIVE MEASURES .............................................................................................................. 5-1 

5.1 Protective Measures Related to Acoustic Effects ....................................................................... 5-1 

5.1.1 Evolution of the Current Mitigation Measures .............................................................. 5-1 

October 2007 USWEX EA/OEA iii


5.1.2 Alternative Mitigation Measures Considered but Eliminated ....................................... 5-2 

5.1.3 Current Exercise Mitigation Measures .......................................................................... 5-7 

5.1.3.1 Personnel Training ............................................................................................ 5-7 

5.1.4 NDE II Protective Measures for Major Exercises (Jan 2007- Jan 2009) ....................... 5-8 

5.1.5 Conservation Measures ................................................................................................ 5-12 

5.1.6 ESA Prudent Mitigation Measures, Tearms and Conditions ....................................... 5-13 

5.1.7 USWEX After-Action Reports .................................................................................... 5-16 

6.0 CONSULTATION AND COORDINATION..................................................................................... 6-1 

7.0 CONCLUSIONS AND RECOMMENDATIONS ............................................................................. 7-1 

8.0 OTHER CONSIDERATIONS ............................................................................................................ 8-1 

8.1 Adverse Environmental Effects That Cannot Be Avoided ......................................................... 8-1 

8.2 Consistency with Federal, Regional, State, Local, or Native American Land-Use Plans, 

Policies, and Controls ................................................................................................................. 8-1 

8.3 Energy Requirements and Conservation Potential ..................................................................... 8-1 

8.4 Irreversible or Irretrievable Commitment of Resources ............................................................. 8-1 

8.5 Relationship Between Short-Term Uses of the Human Environment and the Maintenance and 

Enhancement of Long-Term Productivity .................................................................................. 8-2 

8.6 Natural or Depletable Resource Requirements and Conservation Potential .............................. 8-2 

8.7 Federal Action to Address Environmental Justice in Minority Populations and Low-Income 

Populations ................................................................................................................................. 8-2 

8.8 Federal Action to Address Protection of Children from Environmental Health Risks and 

Safety Risks ................................................................................................................................ 8-2 

8.9 Public Notice and Comment ...................................................................................................... 8-2 

8.9.1 Thresholds for Modeling ............................................................................................... 8-3 

8.9.2 Lack of Evidence of Impacts or Sonar Related Strandings in Hawaii ........................... 8-3 

8.9.3 Non-Auditory Impacts ................................................................................................... 8-4 

8.9.4 Sonar Mitigations .......................................................................................................... 8-4 

8.9.5 Population Impacts ........................................................................................................ 8-4 

8.9.6 Cumulative Impacts ....................................................................................................... 8-5 

8.9.7 Other .............................................................................................................................. 8-5 

9.0 REFERENCES ................................................................................................................................... 9-1 

10.0 LIST OF PREPARERS ................................................................................................................... 10-1 

List of Appendices 

A THREATENED AND ENDANGERED SPECIES LISTS 

B USWEX ACOUSTIC MODELING RESULTS 

C 2006 RIM OF THE PACIFIC EXERCISE AFTER ACTION REPORT 

D PUBLIC COMMENTS (Volume 2) 

iv USWEX EA/OEA October 2007


List of Figures 

Page 

Figure 1-1 Hawaii Range Complex EA/OEA Study Area, Hawaiian Islands ....................................... 1-4 

Figure 2-1 Undersea Warfare Exercise Anti-Submarine Warfare (USWEX ASW) Acoustic 

Exposure Modeling Areas, Hawaiian Islands ...................................................................... 2-4 

Figure 3-1 Amphibious Exercise (AMPHIBEX) Areas—Pacific Missile Range Facility (PMRF), 

Kauai, Hawaii ....................................................................................................................... 3-3 

Figure 3-2 Airspace Use Surrounding Pacific Missile Range Facility, Hawaiian Islands ..................... 3-4 

Figure 3-3 High and Low Altitude Airways, Hawaiian Islands ............................................................. 3-6 

Figure 3-4 Marine Corps Training Area–Bellows, Oahu, Hawaii ......................................................... 3-8 

Figure 3-5 Pohakuloa Training Area, Hawaii, Hawaii ........................................................................ 3-15 

Figure 4-1 Summary of the Acoustic Effects Criteria and Thresholds ................................................ 4-22 

List of Tables 

Page 

Table 1-1 Component Areas of Hawaii Range Complex for USWEX ................................................ 1-5 

Table 2-1 Hawaiian Islands Operating Area Descriptions ................................................................... 2-1 

Table 2-2 Typical Sonar Usage During One USWEX ......................................................................... 2-8 

Table 3-1 USWEX Resource Area Summary ...................................................................................... 3-2 

Table 3-2 Marine Mammals that May Occur in the Hawaiian Islands Operating Area ..................... 3-23 

Table 4-1 Acoustic Effects Criteria and Thresholds ........................................................................... 4-22 

Table 4-2 Single USWEX Mid-Frequency Active Tactical Sonar Acoustic Model Results by 

Season ................................................................................................................................ 4-24 

Table 4-3 USWEX Alternative 1 Mid-Frequency Active Tactical Sonar Acoustic Model Results 

(173 dB) ............................................................................................................................. 4-25 


(190 dB) ............................................................................................................................. 4-26 


(173 dB) ............................................................................................................................. 4-38 


(190 dB) ............................................................................................................................. 4-39 

Table 4-7 USWEX Landside Cumulative Impacts Summary ............................................................ 4-44 

October 2007 USWEX EA/OEA v


THIS PAGE INTENTIONALLY LEFT BLANK 

vi USWEX EA/OEA October 2007

Acronyms and Abbreviations 


AAV 

ACM 

AMPHIBEX 

AOR 

ARTCC 

ASMEX 

ASW 

ASWEX 

ATCAA 

CEQ 

CFR 

cm 

CPF 

CSG 

CV 

CZMA 

CZMA 

dB 

dBA 

DEIS 

DoD 

EA 

EEZ 

EFH 

EFV 

EIS 

EL 

EO 

ESA 

ESG 

FACSFAC 

FONSI 

FRP 

FRTP 

ft 

GNFPP 

GUNEX 

HRC 

Hz 

ICAO 

IHA 

INST 

kHz 

km 

LCAC 

Amphibious Assault Vehicle 

Air Combat Maneuvering 


Area of Responsibility 

Air Route Traffic Control Center 

Air-to-Surface Missile/Bomb Exercise 

Anti-Submarine Warfare 

Anti-Submarine Warfare Exercise 

Air Traffic Control Assigned Airspace 

Council on Environmental Quality 

Code of Federal Regulations 

Centimeter(s) 

Commander, Pacific Fleet 

Carrier Strike Group 

Coefficient of Variation 

Coastal Zone Management 

Coastal Zone Management Act 

Decibel(s) 

A-weighted decibel(s) 

Draft Environmental Impact Statement 

Department of Defense 

Environmental Assessment 

Exclusive Economic Zone 

Essential Fish Habitat 

Expeditionary Fighting Vehicle 

Environmental Impact Statement 

Energy Flux Density Level 

Executive Order 

Endangered Species Act 

Expeditionary Strike Groups 

Fleet Area Control and Surveillance Facility 

Finding of No Significant Impact 

Fleet Response Plan 

Fleet Readiness Training Plan 

Feet 

Global Naval Force Presence Posture 

Gun Exercise 

Hawaii Range Complex 

Hertz 

International Civil Aviation Organization 

Incidental Harassment Authorization 

Instruction 

Kilohertz 

Kilometer(s) 

Landing Craft, Air Cushioned 

October 2007 USWEX EA/OEA ac-1


L eq 

m 

MCBH 

MCTAB 

MINEX 

μPa 

mm 

MMPA 

MSAT 

NDE 

NEPA 

nm 

nm 2 

NMFS 

NOAA 

NOTAM 

NOTMAR 

OEA 

OEIS 

OPNAVINST 

PIRO 

PMRF 

PTA 

PTS 

R&D 

RDT&E 

RDX 

RIMPAC 

SINKEX 

SPL 

STWEX 

SURTASS LFA 

T&E 

TORPEX 

TRACKEX 

TS 

TTS 

USWEX 

U.S.C. 

Energy-Equivalent Sound Level 

Meter(s) 

Marine Corps Base Hawaii 

Marine Corps Training Area, Bellows 

Mine Warfare Exercise 

Micro-Pascal(s) 

Millimeter 

Marine Mammal Protection Act 

Marine Species Awareness Training 

National Defense Exemption 

National Environmental Policy Act 

Nautical Mile(s) 

Square Nautical Mile(s) 

National Marine Fisheries Service 

National Oceanic and Atmospheric Administration 

Notice to Airmen 

Notice to Mariners 

Overseas Environmental Assessment 

Overseas Environmental Impact Statement 

Chief of Naval Operations Instruction 

Pacific Islands Regional Office 

Pacific Missile Range Facility 

Pohakuloa Training Area 

Permanent Threshold Shift 

Research and Development 

Research, Development, Test and Evaluation 

Common name of the chemical cyclotrimethylenetrinitramine 

Rim of the Pacific Exercise 

Sinking Exercise 

Sound Pressure Level 

Strike Warfare Exercise 

Surveillance Towed Array Sensor System Low Frequency Active 

Test & Evaluation 

Torpedo Exercise 

Tracking Exercise 

Threshold Shift 

Temporary Threshold Shift 

Undersea Warfare Exercise 

United States Code 

ac-2 USWEX EA/OEA October 2007

1.0 Purpose and Need for Proposed Action 

1.0 PURPOSE AND NEED FOR PROPOSED 

ACTION 

1.1 INTRODUCTION 

The Preamble of the Constitution of the United States, established the principle that the people of the 

United States will provide for the common defense. Article 1, Section 8 of the Constitution states, “The 

Congress shall have power To …. provide for the common defense …. provide and maintain a Navy” and 

“To make Rules for the Government and Regulation of the land and Naval Forces (capitalization 

retained).” To implement these constitutionally mandated duties, Congress provided United States Code 

Title 10, Section 5062 (U.S.C. § 5062), which states: “The Navy shall be organized, trained, and equipped 

primarily for prompt and sustained combat incident to operations at sea.” 

In order to have a Navy that is ready for prompt response with the ability to carry out sustained combat at 

sea, Title 10 U.S.C. § 5062 establishes and charges the Chief of Naval Operations (CNO) with 

responsibility for ensuring the readiness of the Nation’s naval forces. The CNO meets that directive, in 

part, by establishing and executing training programs, including at-sea training and exercises, and 

ensuring naval forces have access to the ranges, training areas, and airspace necessary to develop and 

maintain skills for the conduct of naval operations. The Undersea Warfare Exercises (USWEX) events 

taking place in Hawaii fulfill part of the Navy’s mission as required by Federal law and the objectives set 

by CNO to insure the Navy can, if necessary, conduct prompt and sustained combat at sea. 

This Programmatic Environmental Assessment (EA)/Overseas EA (OEA) has been prepared by the 

Department of the Navy in compliance with the National Environmental Policy Act (NEPA) of 1969 (42 

United States Code (U.S.C.) § 4321 et seq.); the Council on Environmental Quality (CEQ) Regulations 

for Implementing the Procedural Provisions of NEPA (Title 40 Code of Federal Regulations (CFR) §§ 

1500-1508 (2005)); Department of the Navy Procedures for Implementing NEPA (32 CFR §775 (2005)); 

and Executive Order (EO) 12114, Environmental Effects Abroad of Major Federal Actions. The NEPA 

process ensures that environmental impacts of proposed major federal actions are considered in the 

decision-making process. EO 12114 requires environmental consideration for actions that may 

significantly harm the environment of the global commons (e.g., environment outside U.S. Territorial 

Seas). This EA/OEA satisfies the requirements of both NEPA and EO 12114. The analysis in this 

EA/OEA covers the remainder of the 2-year time period from January 2007 through January 2009. 

1.2 BACKGROUND 

USWEX is an assessment based ASW exercise conducted by the U.S. Navy’s Carrier Strike Groups 

(CSG) and Expeditionary Strike Groups (ESG) while in transit from the west coast of the United States to 

the Western Pacific Ocean. Along with the assessment goal, there is significant training value in USWEX, 

as training is inherent in all at-sea exercises. Training may be considered a subset of the USWEX efforts 

designed to assess our ability to conduct Anti-Submarine Warfare (ASW) in the most realistic 

environment, against the level of threat expected in order to effect changes to both training and 

capabilities, (e.g., equipment, tactics, and changes to size and composition of the Strike Groups and 

manning). While other training exercises occur during the remainder of the deployment, USWEXs are 

October 2007 USWEX EA/OEA 1-1


conducted shortly after deployment to ensure the Strike Groups are fully capable of conducting strike 

warfare while defending themselves against submarines. The USWEX assessment allows additional crew 

ASW training opportunity to occur at this junction because skill sets diminish over time and it is 

necessary to ensure the Strike Group maintains and improves upon critical ASW skill sets. 

The USWEX assessment provides the Commander, U.S. Pacific Fleet, the ability to identify future ASW 

requirements. The USWEX assessment efforts have been instrumental and directly responsible for a 

significant increase in Navy ASW investments and positive changes to our tactics, thereby improving our 

ASW capabilities. Not assessing the ASW ability of a Strike Group to succeed at the highest level 

possible when there is the opportunity to do so would present an overwhelming national security concern, 

as the failure to do so could result in significant adverse results in combat, including the loss of ships and 

life. 

The ESG is a relatively new naval organizational structure, having been established in 2003 as part of 

ongoing transformation processes in the Department of the Navy. An ESG typically consists of the 

following: amphibious assault ship; amphibious transport dock ship; dock landing ship; guided missile 

cruiser; guided missile destroyer; frigate; attack submarine; marine expeditionary unit; AV-8B Harrier II 

aircraft; CH-53E Super Stallion helicopters; CH-46D Sea Knight helicopters; and AH-1W Super Cobra 

helicopters. The CSG organizational structure likewise reflects enhanced operational capabilities for 

formations formerly known as carrier battle groups. The CSG typically consists of the following: aircraft 

carrier with 75 to 85 aircraft; two guided missile cruisers; two guided missile destroyers; two attack 

submarines; and ammunition, oiler, and supply ships. Larger naval formations, such as a two-carrier 

formation—a Carrier Strike Force—are possible. 

The deployment of naval forces is determined by the Joint Chiefs of Staff, based on the requirements of 

the Unified Commanders. In order to meet operational requirements, most notably for CSG and ESG 

deployments, these forces are apportioned. This apportionment for the U.S. Navy and U.S. Marine Corps 

is known as the Global Naval Force Presence Posture (GNFPP). The GNFPP addresses where and when 

Strike Groups with embarked Marine Air-Ground Task Forces are deployed throughout the world. The 

dynamic requirements of national security and other operational commitments, affect the deployment of 

naval forces. As a result, the GNFPP is not a fixed deployment schedule but is flexible and often changes 

to meet the Nation’s security needs. As these changing operational needs impact the deployment 

schedules of naval forces, they subsequently affect the training cycles required to ensure that these forces 

are adequately trained to conduct assigned missions. As an example, Strike Group training dates cannot 

be fixed to a month or even a season on a recurring annual basis. Real-world contingencies drive the 

training schedule in relation to when the Strike Group is required to be in a Unified Commander’s area of 

responsibility. To meet this readiness challenge and the demands of the GNFPP, the U.S. Navy executes 

its Fleet Response Plan (FRP). The FRP calls for the capability to deploy or surge Strike Groups in a 

very short time. 

The deployment training cycle for the Strike Group comprises pre-deployment training and certification, 

deployment, and post-deployment maintenance. The USWEX is an important component of the training 

and deployment of naval forces organized into ESGs and CSGs. The objective of USWEX is to enhance 

the interoperability and proficiency of naval surface, subsurface, and air forces to counter submarine 

threats in the context of littoral operations. The training environment of the USWEX replicates expected 

operating conditions as realistically as practicable. USWEX also demonstrate the ability of a naval force 

to communicate and operate in simulated hostile scenarios. The vast size of the HRC allows a CSG/ESG 

1-2 USWEX EA/OEA October 2007


to train in a realistic manner, unfettered by artificial and unrealistic geographic boundaries exercise. In 

addition, the presence of the instrumented tracking ranges at Pacific Missile Range Facility (PMRF), the 

presence of various Department of Defense (DoD)-controlled beaches enabling amphibious landing 

training while conducting ASW, the ability for fixed-wing aircraft sorties to the Pohakuloa Training Area 

(PTA) (island of Hawaii) and rotary aircraft to fly sorties to Kaula while their Strike Group conducts 

ASW, and the presence of submarines homeported at Pearl Harbor which can serve as an opposition 

force) all contribute to Hawaii being the best location for this training. Based on the U.S. Navy’s FRP, 

which governs deployment training cycles and global deployment of naval forces, the U.S. Pacific Fleet 

anticipates the need to conduct between four and six USWEXs annually. 

This EA/OEA identifies the Proposed Action as a consolidated set of exercise events that comprise a 

USWEX, and the areas where it could be conducted. The EA/OEA evaluates environmental impacts of 

USWEX training activities, assuming that the typical USWEX involves maximum usage of assets during 

the course of all training events that are conducted during the exercise. 

This EA/OEA analyzes mid-frequency active tactical sonar use associated with the USWEX. As a result 

of scientific advances in acoustic exposure effects-analysis modeling on marine mammals, action 

proponents now can quantitatively estimate acoustic exposure effects on marine mammals. This EA/OEA 

documents an acoustic exposure effects-analysis on marine mammals that may be affected by the 

USWEX training events and use of mid-frequency active tactical sonar. 

1.3 OVERVIEW OF HAWAII RANGE COMPLEX 

A range complex is an organized and designated set of specifically bounded geographic areas which can 

encompass a landmass, body of water (above or below the surface), and airspace used to conduct training, 

research and development (R&D), and test and evaluation (T&E) of military hardware, personnel, tactics, 

munitions, explosives, or electronic combat systems. A range complex can consist of several ranges, 

operating areas, and special use airspace. These areas can be under strict control of the Department of 

Defense (DoD) or its agencies, or can be shared among several agencies. The HRC geographically 

encompasses offshore, nearshore, and onshore areas located on or around the major islands of the 

Hawaiian Islands chain. The offshore areas extend from 17 to 25 degrees north latitude and from 154 to 

162 degrees west longitude, forming an area approximately 480 nautical miles (nm) by 355 nm 

(Figure 1-1). 

The HRC provides the geography, infrastructure, space, and location necessary to accomplish USWEX 

training. The large area available to deploy forces within HRC allows a CSG/ESG to train using a 

geographic scope that replicates possible real world events, with the channels between islands serving as 

strategic choke-points to ocean commerce. The presence of the instrumented tracking ranges at PMRF as 

well as DoD-controlled warning areas and special use airspace also enable USWEX to proceed in a safe 

and structured manner while retaining the flexibility for controllers to interject tactical challenges to 

enhance realism for exercise participants. Given that USWEX is an event tailored to challenge a 

CSG/ESG, the HRC provides the ability for a CSG to conduct air strikes sorties to PTA and for an ESG to 

conduct amphibious landing on DoD beaches, both while simultaneously conducting anti-submarine 

warfare. Finally, the presence of submarines homeported at Pearl Harbor provides access to these 

submarines, which can then serve as an opposition force during the USWEX event without having to 

transit to participate in the exercise events. 



WORKING PAPERS 

Nene 

W-188 W-188 

(Rainbow) 

Northern Pacific Ocean 

W-189 

R-3101 

PMRF 

W-190 

R-3107 

W-187 

Kaula 

W-186 

R-311B 

W-196 

A-311 

Pali 

Marine Corps Training 

Area - Bellows 

Mela North 

Quint 

Taro 

W-191 


Mela Central 

Mela South 

W-192 

W-193 

W-194 

Pele 

R-3103 

Mako 

Lono West 

Lono East 

Lono Central 

EXPLANATION 

12 nautical mile Territorial Limit 

Hawaiian Islands Operating Area 

Special Use Airspace 


0 50 100 200 Kilometers 

Barking Sands Tactical 

Underwater Range 

(BARSTUR) Hydrophones 

Barking Sands Underwater 

Range (BSURE) Hydrophones 

Military 

Land 

Hawaii Range Complex 

EA/OEA Study Area 

Hawaiian Islands 

North 

0 50 100 200 Nautical Miles 

Figure 1-1 

060530_HI EA-OEA.eps 

1-4 

USWEX EA/OEA 

1-3 

October 2007


The HRC includes the southern tip of the Papahanaumokuakea Marine National Monument (Monument) 

where part of the 50-mile buffer around the islands within the monument extends into the traditionally 

used exercise area and adjacent ranges at PMRF. Use of the Monument “for activities and exercises of 

the Armed Forces of the United States” was codified when the Monument was established. Except for the 

southeast tip of the monument where the 50-mile buffer extends from Nihoa into W-188, USWEX 

activities are not currently planned within the Monument. This area encompasses about 3,311 square 

miles of the entire Monument’s 139,793 square miles. USWEX exercise activities are not currently 

contemplated to occur within that portion of W-188 that overlaps with the Monument. 

Figure 1-1 and Table 1-1 summarize the component areas of the HRC that could host all or portions of a 

USWEX. These ranges and operating areas are used by naval and other military forces of the United 

States and allied nations to conduct operations and training in tactics, techniques, and procedures utilizing 

weapons, systems, equipment, and munitions, and to conduct research, development, test, and evaluation 

(RDT&E) activities. 

Component Area 


Pacific Missile Range Facility 

Marine Corps Training Area Bellows 

Table 1-1. Component Areas of Hawaii Range Complex for USWEX 

Description 

Sea and airspace including Warning Areas W-188 (Rainbow only), W-187, 

W-189, W-190, W-191, W-192, W-193, W-194, W-196; Air Traffic 

Control Assigned Airspace; and other open ocean areas 

Amphibious exercise landing area and R-3101 airspace, Barking Sands 

Tactical Underwater Range, Barking Sands Underwater Range Extension, 

W-186 airspace, and W-188 (plus the Kuku extension) 

Amphibious exercise landing area 

Pohakuloa Training Area Air-to-Ground target impact area on the island of Hawaii, including R 3103 

Kaula 

Air-to-Ground target range on the island of Kaula, including R-3107 and 

W-187 

1.4 SCOPE AND CONTENT OF THE EA/OEA 

An EA is a concise public document for which a federal agency is responsible that serves to: (1) provide 

sufficient evidence and analysis to determine whether preparation of an Environmental Impact Statement 

(EIS) or Finding of No Significant Impact is appropriate; (2) aid the agency in complying with NEPA 

when no EIS is necessary, or in preparing an EIS if necessary; and (3) discuss the environmental impacts 

of a Proposed Action and alternatives (40 CFR 1508.9). An OEA ensures that the programs and actions 

of the federal government meet the policies and goals set forth in EO 12114. The U.S. Navy considers 

potential environmental impacts in conjunction with other relevant information to plan actions and make 

decisions. 

The geographic scope of this EA/OEA (Study Area) includes the 210,000 square nautical miles (nm 2 ) of 

ocean area within the Hawaiian Islands Operating Area. As noted previously, USWEX activities are not 

currently planned to be conducted within the Papahanaumokuakea Marine National Monument. This 

EA/OEA will provide a programmatic evaluation of current and proposed USWEX training activities 

through January 2009. 



1.5 PURPOSE AND NEED 

The purpose of the Proposed Action is to achieve and maintain Fleet readiness using the HRC to support 

west-coast based Strike Groups after deployment and before entering the Seventh Fleet Area of 

Operations, and to achieve and maintain Fleet readiness of Hawaii homeported ships and submarines as 

well. 

The need for the Proposed Action stems from the following: 

• Maintain and improve current levels of naval readiness in the context of undersea warfare, as 

required by the laws and directives governing the training of the Armed Forces, by conducting 

assessment and training in the HRC for deployed, deploying, and locally-based naval forces. 

• Support the requirements of the GNFPP and FRP, including current training requirements and 

future increases in operational training tempo for deployment and sustainment training in the 

context of undersea warfare exercises in the HRC. 

• Demonstrate strike warfare capabilities of the strike group while establishing and maintaining 

control over any threats posed by submarines. CSGs must demonstrate the ability to enter a 

theater, transit through littoral waterspace that restricts the maneuverability of the strike group, 

establish an operating area, and conduct air strikes against land and sea based targets. The ESG 

must demonstrate the ability to enter a theater, transit through littoral waterspace that restricts the 

maneuverability of the strike group, establish an operating area, and conduct amphibious warfare 

operations in a shallow littoral environment. 

• The USWEX must occur post-Joint Task Force Exercise and during deployment. 

• The USWEX capabilities must occur before entering the Seventh Fleet Area of Responsibility 

(AOR). 

• The USWEX must occur where U.S. controlled land based ranges are readily available. 

• The USWEX must occur where U.S. naval facilities are able to support the exercise. This 

includes the use of P-3 aircraft and submarines that are able to participate. 

• The Commander, U.S. Pacific Fleet (CPF) task force responsible for running the ASW training 

module must be co-located for this USWEX series to occur. 

1.6 RELATED ENVIRONMENTAL DOCUMENTS 

According to CEQ regulations for implementing NEPA, material relevant to an EA may be incorporated 

by reference with the intent of reducing the size of the document. The NEPA compliance documents for 

some of the programs and projects within the geographical scope of this EA/OEA include: 

• Final Environmental Assessment for Temporary Hawaiian Area Tracking System, 

U.S. Department of the Navy, June 1994 

• Supplemental Environmental Assessment for Temporary Hawaiian Area Tracking System, 

U.S. Department of the Navy, 1996 



• Rim of the Pacific (RIMPAC) Programmatic Environmental Assessment, U.S. Department of the 

Navy, 2002 

• Rim of the Pacific (RIMPAC) Supplement to the 2002 Programmatic Environmental Assessment, 

U.S. Department of the Navy, 2004 and U.S. Department of the Navy, 2006 

• Hawaiian Islands Humpback Whale National Marine Sanctuary Final Environmental Impact 

Statement, National Oceanic and Atmospheric Administration (NOAA), 1997 

• Final Environmental Impact Statement for Land Use and Development Plan, Bellows Air Force 

Station, Waimanalo, Hawaii, U.S. Pacific Command, 1995 

• Final Environmental Impact Statement Transformation of the 2 nd Brigade, 25 th Infantry Division 

(L) to a Stryker Brigade Combat Team in Hawaii, U.S. Department of the Army, Office of the 

Secretary of the Army and U.S. Army Corps of Engineers, Honolulu Engineer District, 2004 

• Environmental Assessment/Overseas Environmental Assessment of the SH-60R Helicopter/ALFS 

Test Program, October 1999 

• Final Environmental Impact Statement for the Pacific Missile Range Facility Enhanced 

Capability, December 1998 





2.0 Description of Proposed Action and Alternatives 

2.0 DESCRIPTION OF PROPOSED ACTION 

AND ALTERNATIVES 

This chapter provides detailed information on the Proposed Action and alternatives analyzed in the 

USWEX EA/OEA. Three alternatives are analyzed in this EA/OEA. Two additional alternatives were 

considered, but eliminated from further analysis due to their incompatibility with the stated purpose and 

need of the Proposed Action. 

This chapter is divided into four major sections: Section 2.1 describes the Hawaiian Islands Operating 

Area, Section 2.2 describes the major elements of the Proposed Action, Section 2.3 describes the 

alternatives analysis, Section 2.4 describes alternatives for implementing the Proposed Action, and 

Section 2.5 describes the No-Action Alternative. 

2.1 DESCRIPTION OF THE HAWAIIAN ISLANDS OPERATING AREA 

The Hawaiian Islands Operating Area consists of airspace, sea space, and undersea space surrounding the 

Hawaiian Islands (refer to Figure 1-1). Table 2-1 provides an overview of each area and its location. 


Operating Area 

Northern Warning Areas 

W-188 Rainbow, 

W-189, 

W-190 

Southern Warning Areas 

W-192, W-193, 

W-194 

Table 2-1. Hawaiian Islands Operating Area Descriptions 

Description 

Oahu is essentially the center of the range complex. The northern Warning Areas 

comprise sea space and airspace north of Oahu. All are available from the surface to an 

unlimited altitude and are used for surface and air operations. Conventional ordnance is 

authorized, except that sonobuoy drops require the issuance of a Notice to Mariners 

(NOTMAR). These and all other Hawaii Offshore Warning Areas have published 

hours of 7:00 a.m. to 10:00 p.m. Monday through Friday and 8:00 a.m. to 4:00 p.m. 

Saturday and Sunday. Other times by Notice to Airmen (NOTAM) and NOTMAR. 

The southern Warning Areas comprise sea space and airspace located south of Oahu. 

Available from surface to unlimited altitude, they are used for air and surface 

operations. Only conventional ordnance is authorized. NOTMAR required for 

sonobuoy drops. 

W-191 W-191, located directly south of Oahu, is available from surface to 3,000 feet (ft) for 

air and surface operations and conventional ordnance. NOTMAR required for 

sonobuoy drops. 

W-196 W-196 is used for surface and helicopter operations only. W-196 extends from surface 

to 2,000 ft and is not available to fixed-wing aircraft. Authorized ordnance includes 

conventional ordnance (surface gunnery limited to less than 3-inch caliber guns). 

Kapu/Quickdraw, 

Wela Hot Areas 

Kapu/Quickdraw and Wela Hot Areas, also known as Special Operations Areas 4 and 

6, respectively, are located completely within W-192. Area uses include: surface, air, 

and Anti-Air Warfare gunnery; air-to-surface bombing and gunnery; and jettisoning 

ordnance. Both areas have a continuous NOTMAR in effect during the published hours 

of 7:00 a.m. to 10:00 p.m. Monday through Friday and 8:00 a.m. to 4:00 p.m. Saturday 

and Sunday. 



Table 2-1. Hawaiian Islands Operating Area Descriptions (Continued) 


Description 

Operating Area 

Air Traffic Control Assigned Airspace (ATCAA) 

Nene 

Nene is the only ATCAA associated with the northern Warning Areas. It is typically 

activated for use during Hawaii Air National Guard intercept training. 

Pali 

Pali is roughly a 40 nautical mile (nm) circular area over the island of Oahu, from 

Flight Level 250 to unlimited, although normally not available below Flight Level 

280. Pali is used by high altitude aircraft transiting between the northern and southern 

Warning Areas. 

Taro 

Taro overlays W-191, sharing the same boundaries and, when available, extends its 

airspace from 3,000 ft to 16,000 ft. This airspace allows aircraft to remain in 

controlled airspace while transiting above W-191’s 3,000-ft ceiling. 

Quint 

Quint is located 45 nm southwest of Honolulu, with available airspace from Flight 

Level 250 to unlimited altitude, although usually not available below Flight Level 

280. Quint is seldom used, but is sometimes activated to provide additional airspace 

when needed. 

Mela North, Mela The Mela ATCAAs connect the western border of W-192 with the southern border of 

Central, Mela South W-186 (Pacific Missile Range Facility). Available from the floor of controlled 

airspace (1,200 ft) to unlimited except for Mela North which has a ceiling of 15,000 

ft. The Mela ATCAAs are frequently active during the Undersea Warfare Exercise 

(USWEX) to provide more airspace for carrier strike group operations. Outside of 

USWEX, P-3s and ship borne SH-60Bs conduct training here. 

Mako, Lono West, The Mako and Lono ATCAAs are available to extend the Special Use Airspace of 

Lono Central, Lono Mela South, W-192, W-193, and W-194 by an additional 104 nm. All are available 

East 

from floor of controlled airspace to unlimited and are activated to provide more 

southern area airspace. The Lono ATCAA is especially useful to the aircraft carrier 

during USWEX. Its location allows easy access to Pohakuloa Training Area for 

launching air strikes. 

Pele 

Pele provides a transit corridor from W-194 and Lono East into R-3103 airspace over 

Pohakuloa Training Area on Hawaii. When activated, Pele extends from 16,000 ft to 

Flight Level 290. 

Submarine Operating Areas 

Grid Operating Area The Grid Operating Area encompasses the entire area of the Hawaii Islands 

Operating Area Descriptions. The Hawaii grid system consists of letter designated 

East-West rows that are 20 minutes of latitude and number designated North-South 

columns that are 20 minutes of longitude. The grid system is bounded by 17N, 25N, 

154W, and 162W, excepting grid area controlled by Commanding Officer, Pacific 

Missile Range Facility. 

Hawaii Area Tracking The former Hawaii Area Tracking System range no longer contains an instrumented 

System Range tracking system, but the name has remained, referring to an area in the Maui basin, 

centered approximately 9 nm southwest of Maui, situated among the islands of Maui, 

Kahoolawe, and Lanai. The location is a popular submarine training area due to its 

highly reverberant acoustic environment and shallow depths of 300 to 600 ft. The 

range is located completely within the Hawaiian Islands Humpback Whale National 

Marine Sanctuary. 



2.2 PROPOSED ACTION 

The Proposed Action is to sustain the U.S. Navy’s ASW capabilities by conducting USWEXs in the HRC 

for deploying west-coast based CSGs and ESGs and Hawaii homeported ships and submarines. CSGs and 

ESGs that deploy from the west coast of the United States will experience realistic submarine combat 

conditions and assess submarine warfare training postures in the Hawaii Operations Area prior to their 

deployment to a theater of operations. HRC training areas, test ranges, and ocean operating areas would 

be utilized to fully support the Fleet Readiness Training Plan (FRTP). The purpose of the Proposed 

Action is to achieve and maintain Fleet readiness using the HRC to support current and future ASW 

training with up to six USWEXs annually. 

ASW training conducted during a USWEX utilizes ships, submarines, aircraft, non-explosive exercise 

weapons, and other training systems and devices. The use of mid-frequency active tactical sonar in ASW 

training has been occurring in the Hawaiian Islands for approximately 40 years using the same basic 

equipment with no direct evidence of harm to marine mammals. Nearly all USWEX ASW training would 

occur in the six areas delineated in Figure 2-1. ASW events typically occur in one or more of these six 

ASW areas. While ASW events could occur throughout the approximate 210,000 nm 2 of the Hawaiian 

Islands Operating Area, most events would occur within the approximate 46,000 nm 2 of these six areas, 

which were used for analysis as being representative of the marine mammal habitats and the bathymetric, 

seabed, wind speed, and sound velocity profile conditions within the entire Hawaiian Islands Operating 

Area. For purposes of this analysis, all likely USWEX ASW events were modeled as occurring in these 

six areas. Each USWEX may include one ASW event that occurs within a channel area focused on 

restricted maneuverability. 

As a combined force, submarines, surface ships, and aircraft will conduct ASW against opposition 

submarine targets. Submarine targets include real submarines, target drones that simulate the operations 

of an actual submarine, and virtual submarines interjected into the training events by exercise controllers. 

ASW training events are complex and highly variable. For the USWEX, the primary event involves from 

one to five surface ships equipped with sonar, with one or more helicopters, and a P-3 aircraft searching 

for one or more submarines. Four to six USWEXs will be conducted annually over a period of 2 years, 

with an average event length of approximately 72 to 96 hours. A total of 1,167 hours of active sonar 

training were modeled for USWEX acoustic effects. This total includes all potential ASW training that is 

expected to occur during the maximum number of six USWEXs annually in Hawaii. For each ESG 

USWEX there would be 139.5 hours of active sonar training, and for each CSG USWEX there would be 

222 hours of active sonar training. 

A USWEX is a complex, large-scale exercise in which a Strike Group must establish a safe operating area 

from where strike operations against land targets are conducted. The simultaneous conduct of both ASW 

and strike missions fully stresses the strike group, providing essential refresher training. Establishing a 

secure operating area requires deploying assets over a large geographic area to locate and prosecute 

simulated enemy submarines. Within this larger exercise, smaller ASW exercises are conducted that 

refine ASW crews’ skills. During a USWEX, units will conduct ASWEX, which include Anti-Submarine 

Warfare Tracking Exercises (ASW TRACKEX), and Anti-Submarine Torpedo Exercise (ASW 

TORPEX). Submarines participating in the exercise are engaged in detecting and engaging, and avoiding 

detection and engagement by surface ships or submarines simulating enemy forces. Submarines almost 

exclusively use passive sonar to accomplish these tasks. 




Nene 

W-188 W-188 

(Rainbow) 


1 

W-189 

R-3101 

PMRF 

2 

W-190 

R-3107 

W-187 

Kaula 

W-186 

3 

R-311B 

W-196 

A-311 

Pali 



Mela North 

Quint 

Taro 

W-191 

4 


Mela Central 

Mela South 

6 

W-192 

5 

W-193 

W-194 

Pele 

R-3103 

Mako 

Lono West 

Lono East 

Lono Central 

EXPLANATION 


Special Use Airspace 


USWEX ASW Acoustic Exposure 

Modeling Areas 


Barking Sands Tactical 

Underwater Range 

(BARSTUR) Hydrophones 

Barking Sands Underwater 

Range (BSURE) Hydrophones 

Military 

Land 

Undersea Warfare 

Exercise Anti-Submarine 

Warfare (USWEX ASW) 

Acoustic Exposure 

Modeling Areas 


North 

0 50 100 200 Nautical Miles 

Figure 2-1 

060530_USWEX.eps 

2-4 

2-4 USWEX EA/OEA 

October 2007


ASW TRACKEX trains aircraft, ship, and submarine crews in tactics, techniques, and procedures for 

search, detection, localization, and tracking of submarines. No torpedoes are fired during a TRACKEX. 

As the TRACKEX is a unit-level exercise, the participants are typically an aircraft, ship, or submarine 

versus one target submarine or simulated target. The target may be non-evading while operating on a 

specified track, or it may be fully evasive, depending on the training requirements of the operation. 

ASW TORPEX operations train crews in tracking and attack of submerged targets, using active or passive 

acoustic systems, and firing one or two Exercise Torpedoes or Recoverable Exercise Torpedoes. 

TORPEX targets include live submarines, MK-30 ASW training targets, and MK-39 Expendable Mobile 

ASW Training Targets. The target may be non-evading while operating on a specified track or it may be 

fully evasive, depending on the training requirements of the operation. Submarines periodically conduct 

torpedo firing training exercises within the Hawaii Islands Operating Area. 

USWEX is an assessment based ASW exercise conducted by CSG and ESG while in transit from the west 

coast of the United States to the Western Pacific Ocean, their theater of operations. Along with the 

assessment goal, there is significant training value in USWEX, as training is inherent in all at-sea 

exercises. Training may be considered a subset of the USWEX efforts designed to assess our ability to 

conduct ASW in the most realistic environment, against the level of threat expected in order to effect 

changes to both training and capabilities, (e.g., equipment, tactics, and changes to size of the strike groups 

and manning). While other training exercises occur during the remainder of the deployment, USWEXs 

are conducted shortly after deployment to ensure the Strike Group is fully capable of conducting strike 

warfare while defending the Strike Group against submarines. The USWEX assessment may provide 

additional training opportunity to occur at this junction because skill sets diminish over time and it is 

necessary to ensure the Strike Group maintains and improves upon critical ASW skill sets. 

2.2.1 Active Acoustic Devices Utilized During the USWEX 

Tactical military sonars are designed to search for, detect, localize, classify, and track submarines. There 

are two types of sonars, passive and active: 

• Passive sonars only listen to incoming sounds and, since they do not emit sound energy in the 

water, lack the potential to acoustically affect the environment. 

• Active sonars generate and emit acoustic energy specifically for the purpose of obtaining 

information concerning a distant object from the received and processed reflected sound energy. 

Modern sonar technology has developed a multitude of sonar sensor and processing systems. In concept, 

the simplest active sonars emit omnidirectional pulses (“pings”) and time the arrival of the reflected 

echoes from the target object to determine range. More sophisticated active sonar emits an 

omnidirectional ping and then rapidly scans a steered receiving beam to provide directional, as well as 

range, information. More advanced sonars transmit multiple preformed beams, listening to echoes from 

several directions simultaneously and providing efficient detection of both direction and range. 

The tactical military sonars to be deployed in a USWEX are designed to detect submarines in tactical 

operational scenarios. This task requires the use of the sonar mid-frequency range (1 kilohertz [kHz] to 

10 kHz) predominantly. 



The types of tactical acoustic sources that would be used in training events during a USWEX are 

discussed in the following paragraphs. 

• Surface Ship Sonars—A variety of surface ships participate in a USWEX, including guided 

missile cruisers, destroyers, guided missile destroyers, and frigates. Some ships (e.g., aircraft 

carriers) do not have any onboard active sonar systems designed to locate submarines. Others, 

like guided missile cruisers and guided missile destroyers, are equipped with active as well as 

passive sonars for submarine detection and tracking. For purposes of the analysis, all surface ship 

sonars were modeled as equivalent to SQS-53 having the nominal source level of 235 decibels 

(dB) re 1 µPa 2 -s @ 1 m. Since the SQS-53 is the U.S. Navy’s most powerful surface ship sonar, 

modeling this source is a conservative assumption tending towards an overestimation of potential 

effects. Sonar ping transmission durations were modeled as lasting 1 second per ping and 

omnidirectional, which is a conservative assumption that will overestimate potential effects. 

Actual ping durations will be less than 1 second. The SQS-53 sonar transmits at center 

frequencies of 2.6 kHz and 3.3 kHz. Effects analysis modeling used frequencies that are required 

in tactical deployments such as those during a USWEX. Details concerning the tactical use of 

specific frequencies and the repetition rate for the sonar pings are classified; modeling was based 

on the required tactical training setting. 

• Submarine Sonars—Submarine sonars are used to detect and target enemy submarines and 

surface ships. When a submarine uses sonar, enemy ships are alerted to its presence and possible 

location. Therefore, submarines minimize the use of sonar. Because submarine active sonar use 

is very rare and in those rare instances, very brief, it is extremely unlikely use of active sonar by 

submarines would have any effect on marine mammals. Therefore, this type of sonar was not 

modeled for the USWEX. 

• Aircraft Sonar Systems—Aircraft sonar systems that would operate during USWEX include 

sonobuoys and dipping sonar. Sonobuoys may be deployed by P-3 aircraft or helicopters; 

dipping sonars are used by carrier-based helicopters. A sonobuoy is an expendable device used 

by aircraft for the detection of underwater acoustic energy and for conducting vertical water 

column temperature measurements. Most sonobuoys are passive, but some can generate active 

acoustic signals, as well as listen passively. Dipping sonar is an active or passive sonar device 

lowered on cable by helicopters to detect or maintain contact with underwater targets. During the 

USWEX, these systems’ active modes are only used briefly for localization of contacts and are 

not used in primary search capacity. Because active mode dipping sonar use is very brief (2-5 

pulses of 3.5-700 milliseconds with a source level of approximately 201 dB re 1 µPa 2 -s @ 1 m), it 

is extremely unlikely its use would have any effect on marine mammals. The AN/AQS 13 

(dipping sonar) used by carrier based helicopters was determined in the Environmental 

Assessment/Overseas Environmental Assessment of the SH-60R Helicopter/ALFS Test Program, 

October 1999 (Section 3.6.3) not to be problematic due to its limited use and very short pulse 

length. Therefore, the aircraft sonar systems were not modeled for the USWEX. 

• Torpedoes—Torpedoes are the primary ASW weapon used by surface ships, aircraft, and 

submarines. The guidance systems of these weapons can be autonomous or electronically 

controlled from the launching platform through an attached wire. The autonomous guidance 

systems are acoustically based. They operate either passively, exploiting the emitted sound 

energy by the target, or actively, ensonifying the target and using the received echoes for 

guidance. All torpedoes used for ASW during a USWEX would be located in the range area 



managed by the PMRF and would be non-explosive and recovered after use. Potential impacts 

from the use of torpedoes on the PMRF range areas were analyzed in the PMRF Enhanced 

Capability EIS and, consistent with NOAA’s June 3, 2002, Endangered Species Act (ESA) 

Section 7 letter to the U.S. Navy and the RIMPAC 2006 Biological Opinion (see Chapter 6.0), the 

U.S. Navy determined that the potential for effects on marine mammals would not be significant. 

The area ensonified by an active torpedo is relatively small, and the speed of the torpedo reduces 

the potential exposure time. 

• Acoustic Device Countermeasures—Acoustic Device Countermeasures are, in effect, 

submarine simulators that make noise to act as decoys to avert localization or torpedo attacks. 

Previous classified analysis has shown that, based on the operational characteristics (classified 

source output level and frequency) of these acoustic sources, the potential to affect marine 

mammals was low, and therefore they were not modeled for the USWEX. 

• Training Targets—ASW training targets are used to simulate target submarines. They are 

equipped with one or a combination of the following devices: (1) acoustic projectors emanating 

sounds to simulate submarine acoustic signatures; (2) echo repeaters to simulate the 

characteristics of the echo of a particular sonar signal reflected from a specific type of submarine; 

and (3) magnetic sources to trigger magnetic detectors. Based on the operational characteristics 

(source output level or frequency) of these acoustic sources, the potential to affect marine 

mammals is low, and therefore they were not modeled for USWEX. Consistent with NOAA’s 

June 3, 2002, ESA Section 7 letter to the U.S. Navy and the RIMPAC 2006 Biological Opinion 

(see Chapter 6.0), the U.S. Navy determined that the potential for effects on marine mammals 

would not be significant. 

• Range Sources—Range pingers are active acoustic devices that allow each of the in-water 

platforms on the range (e.g., ships, submarines, target simulators, and exercise torpedoes) to be 

tracked by hydrophones in the range transducer nodes. In addition to passively tracking the 

pinger signal from each range participant, the range transducer nodes are capable of transmitting 

acoustic signals for a limited set of functions. These functions include submarine warning 

signals, acoustic commands to submarine target simulators (acoustic command link), and 

occasional voice or data communications (received by participating ships and submarines on 

range). Based on the operational characteristics (relatively low source output level [~190 dB], 

and very short pulse length) of these acoustic sources, the potential to affect marine mammals is 

low, and therefore they were not modeled for the USWEX. Consistent with NOAA’s June 3, 

2002, ESA Section 7 letter to the U.S. Navy and the RIMPAC 2006 Biological Opinion (see 

Chapter 6.0), the U.S. Navy determined that the potential effects on marine mammals would not 

be significant. 

The CSG USWEX occurs over a 96-hour period, generally within ASW modeling areas 4, 5, and 6. The 

ESG USWEX occurs over a 72-hour period, generally within ASW modeling areas 1, 2, and 3. 

Figure 2-1 identifies these areas. Table 2-2 shows the hours of sonar for each USWEX. 




Acoustic 

Exposure 

Modeling Area 

Table 2-2. Typical Sonar Usage During One USWEX 

Total Sonar 

Hours per Ship 

at Each Area 

Number of 

Ships 

Total Sonar 

Hours in Each 

Area 

1 15.5 3 46.5 

Total Sonar 

Hours by 


2 15.5 3 46.5 ESG 139.5 

3 15.5 3 46.5 

4 26 3 78 

5 4 3 12 CSG 222 

6 44 3 132 

2.2.2 Non-ASW Events Occurring During a USWEX 

As the operating area is being secured, strike operations commence against simulated enemy land targets. 

This part of the larger exercise provides strike crews an opportunity to hone their skills enroute to 

deployment. Fixed-wing aircraft will fly sorties to PTA on the island of Hawaii and rotary aircraft will 

fly sorties to Kaula located off the coast of Kauai. Aircraft will utilize these live ranges to drop live or 

inert rounds. These aircraft could participate in the following exercises within the USWEX. 

2.2.2.1 Air-to-Surface Gunnery Exercise (GUNEX) 

GUNEX operations are conducted by rotary-wing aircraft against stationary targets (Floating at Sea 

Target and smoke buoy). Rotary-wing aircraft involved in this operation would include a single SH-60 

using either 7.62-millimeter (mm) or 0.50-caliber door-mounted machine guns. A typical GUNEX will 

last 1 hour and involve the expenditure of approximately 400 rounds of 0.50-caliber or 7.62-mm nonexplosive 

ammunition. 

2.2.2.2 Air Combat Maneuvers (ACM) 

ACM includes Basic Fighter Maneuvers where aircraft engage in offensive and defensive maneuvering 

against each other. These maneuvers typically involve supersonic flight and expenditure of chaff and 

flares. No air-to-air ordnance is released during this exercise. ACM operations within the range complex 

are primarily conducted within W-189, W-190, W-192, W193, and W-194 under Fleet Area Control and 

Surveillance Facility (FACSFAC) Pearl Harbor’s control. These operations typically involve from two to 

eight aircraft; however, based on the training requirement, ACM exercises may involve over a dozen 

aircraft. Sorties can be as short as 30 minutes or as long as 2 hours, but the typical ACM mission occurs 

within the warning area with an average duration of 1.1 hours. 

2.2.2.3 Air-to-Surface Missile/Bomb Exercise (ASMEX) 

An ASMEX provides training for U.S. Navy and U.S. Marine tactical aircrews in air-to-surface missile 

firing; conventional ordnance delivery (including bombing, gunnery, and rocketry); and precision-guided 

munitions firing. Precision-guided munitions include optical, infrared seeking or laser-guided missiles 



fired at surface targets. This event takes place at-sea against ships, boats, small craft, and other maritime 

targets (see GUNEX). An ASMEX event lasts 1 to 2 hours. 

2.2.2.4 Air-to-Ground Strike Warfare Exercise (STWEX) 

This event is similar to the ASMEX except that the targets are land-based. The STWEX exercise 

provides training for U.S. Navy and U.S. Marine Corps fighter and attack aircraft crews in air-to-ground 

missile firing, conventional ordnance delivery (including bombing, gunnery, and rocketry), and precisionguided 

munitions firing. These exercises typically involve a flight of at least 2 aircraft, and can number 

as many as 28 aircraft. Strike aircraft depart from an aircraft carrier or amphibious ship and proceed to 

the training area. Prior to commencing a bombing run, the pilot confirms a clear range with range control 

and requests clearance for weapons delivery. Safety procedures are employed to ensure that personnel on 

the range are not jeopardized. These measures include a requirement that the target be positively 

identified prior to weapons release, a prohibition from bombing through a cloud layer if it obscures the 

target, and no over-flight of shore facilities while carrying live or inert ordnance. The average range time 

is 30 minutes for fighter aircraft and 1 hour for larger aircraft (e.g., S-3, P-3). 

2.2.2.5 Amphibious Exercise (AMPHIBEX) 

During an ESG USWEX, amphibious forces could utilize the beaches at PMRF or at Marine Corps 

Training Area Bellows (MCTAB) to conduct amphibious landings. Embarked Marines would board 

landing craft and practice an amphibious landing that would be consistent with the parameters as set forth 

in the PMRF Enhanced Capability EIS and the RIMPAC Programmatic EA (including the 2004 and 2006 

Supplements). An AMPHIBEX involves the movement of Marine Corps combat and support forces from 

U.S. Navy ships at sea to an objective or an operations area ashore. AMPHIBEXs could involve an 

amphibious assault across a beach, or the insertion of Marines to an inland location called Ship-to- 

Objective Maneuver. The objective of an AMPHIBEX is to provide a realistic training environment for 

conducting amphibious assaults, amphibious raids, reconnaissance, hydrographic surveys, and surf 

condition assessments. Amphibious operations may include shore assault, boat raid, airfield seizure, 

humanitarian assistance, and force reconnaissance. U.S. Navy and U.S. Marine Corps fighter and attack 

aircraft from the CSG and the ESG provide Close Air Support for the amphibious operation. 

Doctrine calls for the capability to conduct amphibious landings by Marine Corps forces launched from 

U.S. Navy ships. For an amphibious assault, Marine Corps task forces come ashore in aircraft and 

landing craft, including Landing Craft Air Cushion (LCAC), Amphibious Assault Vehicles (AAV), and 

Expeditionary Fighting Vehicles (EFV). LCACs are high-speed vessels whose air cushion capability 

allows them to travel across the beach to the desired location for discharging Marines, combat vehicles, 

and cargo. AAVs and EFVs are lightly armored tracked vehicles capable of swimming through the water 

and driving on land, which ferry Marines from ship to shore. Once ashore, the Marine Corps forces 

conduct tactical training, including reconnaissance, movement, attack, defensive actions, force protection, 

and force sustainment. 



2.3 ALTERNATIVES ANALYSIS 

2.3.1 Evaluation Factors/Screening Criteria 

Each of the alternatives must be feasible, reasonable, and reasonably foreseeable in accordance with U.S. 

Navy guidance in Chief of Naval Operations Instruction (OPNAVINST) 5090.1B and CEQ regulations 

(40 CFR Parts 1500-1508). Reasonable alternatives include those that are practical or feasible from the 

technical and economic standpoint and that use common sense. Reasonable alternatives must meet the 

stated purpose and need of the Proposed Action. 

Alternatives were selected based on their ability to meet the following criteria: 

• Meet the operational needs of forces deploying to the western Pacific Ocean prior to arrival at 

their operational location 

• Meet the operational needs of forces returning from deployment after leaving their operational 

area 

• Ability to handle flexible training tempo requirement based on Fleet deployment schedules 

• Proximity to USWEX management team and ASW experts 

• Implement ASW operational training requirements—requirements include physical 

environments similar to those where hostile submarines will be encountered when deployed 

• Proximity to P-3 aircraft and submarines that can support the exercise 

• Proximity of other U.S. Navy aircraft and surface ships that can support the exercise 

• Proximity to readily available U.S. controlled land based ranges 

• Support realistic, unconstrained training within the bounds of sound environmental stewardship 

to the greatest extent practicable. 

2.3.2 Alternatives Eliminated From Further Consideration 

2.3.2.1 Locations other than Hawaii 

Ocean areas off of Guam, California, and Japan were considered for conducting USWEXs. Alternative 

sites outside of Hawaii do not provide reasonable alternatives for required training purposes because of 

the following considerations: 

• USWEX is an advanced ASW exercise managed by Commander, U.S. Pacific Fleet’s (CPF’s), 

ASW experts who are located in Pearl Harbor. 

• Hawaii serves as an ideal enroute training location for units deploying to the western Pacific 

Ocean from the U.S. west coast. P-3 aircraft are located at Marine Corps Base, Hawaii 

(MCBH), and submarines are based at Pearl Harbor. Both play a pivotal role in the USWEX. 

The co-location of these assets is critical for efficiently conducting USWEXs in Hawaii. 

• The Hawaiian Islands Operating Area surrounds the major homeport of Pearl Harbor where a 

large number of ships and submarines are based. Hawaii is also the home for U.S. Navy aircraft 

from five operational squadrons and seven major U.S. Navy commands. The USWEX is the 

last training evolution before the deploying forces report to Commander, U.S. Seventh Fleet, 

and become an operational force. 

• The USWEX simulates a real-world submarine threat and gives an ESG or CSG the opportunity 

to conduct ASW operations as a team prior to embarking on its deployment. 



• Since most ships and squadrons have been training in the continental United States for a period 

as long as 18 months prior to deployment, the Hawaii area provides an opportunity of working 

in an unfamiliar environment, and making real-time adjustments just as they will have to do 

when they reach their station in the Seventh or Fifth Fleet AOR. 

• The operational training needs of deploying forces can not be met after arriving in their 

deployed location in Guam and Japan. 

Other major training exercises occur in California, Guam, and Japan and are being evaluated in separate 

NEPA documents. 

2.3.2.2 Computer Simulation Training 

A simulation alternative would require all naval training to be completed through the use of simulation in 

the place of actual exercises. Computer simulators are already used extensively in the U.S. Navy’s 

training program. Computer technologies provide excellent tools for implementing a successful, 

integrated training program while reducing the risk and expense typically associated with training at sea. 

However, while it is an essential component of training, computer simulation cannot substitute for the 

high-stress environment (such as personnel experience under combat conditions) that would be 

encountered during an actual contingency situation. Simulation does not capture the complexity of 

multiple warfare areas occurring simultaneously and requiring coordination among the various warfare 

commanders. U.S. Navy training doctrine requires live exercises to be conducted for purposes of 

developing and sustaining naval readiness. Consequently, conducting all naval training by simulation is 

deemed inadequate and fails to meet the purpose and need of the Proposed Action. Therefore, this 

alternative was not carried forward for analysis. 

2.4 ALTERNATIVES FOR IMPLEMENTING THE PROPOSED ACTION 

2.4.1 Alternative 1—Six USWEXs Conducted per Year 

Alternative 1 is a proposal designed to meet the maximum expected U.S. Navy and DoD current and 

near-term operational training requirements based on known and expected force structure. This 

Alternative analyzes four CSG USWEXs and two ESG USWEXs per year occurring in Hawaii. Although 

the USWEX is dependent on the U.S. Navy’s operational schedules, this Alternative assumes that half of 

the CSG USWEXs (two) would occur between November and April, and half of the CSG USWEXs 

would occur between May and October. The same ratio is also assumed to apply to the ESG USWEXs. 

The CSGs generally conduct their USWEXs south of Oahu in order to take advantage of the geography 

and also to allow its embarked air wing to conduct training at PTA on the island of Hawaii. The ESGs 

generally conduct their USWEXs north and west of Oahu in order to have the option of conducting 

AMPHIBEX operations at PMRF on Kauai, or at MCTAB on Oahu. In addition to AMPHIBEX, 

USWEX events would include ASWEX, GUNEX, ACM, ASMEX, and STWEX exercises that would 

occur as described in Section 2.2.2. 



2.4.2 Alternative 2—Four USWEXs Conducted per Year 

Alternative 2 is a proposal designed to meet the typical expected U.S. Navy and DoD current and nearterm 

operational training requirements based on known and expected force structure. This Alternative 

analyzes three CSG USWEXs and one ESG USWEX per year occurring in Hawaii. Although the 

USWEX is dependent on the U.S. Navy’s operational schedules, this Alternative assumes that one CSG 

USWEX would occur between November and April, and two CSG USWEXs would occur between May 

and October. The single ESG would occur between May and October. USWEX events would be the 

same as those described for Alternative 1 and include AMPHIBEX, ASWEX, GUNEX, ACM, ASMEX, 

and STWEX exercises that would occur as described in Section 2.2.2. 

2.5 NO-ACTION ALTERNATIVE 

Under the No-Action Alternative, USWEXs would not occur; however, individual training events that 

compose a USWEX would continue to occur on an as-needed basis. Individual ASW training events 

would continue to be environmentally analyzed separately. The Proposed Action includes the 

consolidation of various training activities that are currently being conducted separately into one training 

event (USWEX). The consolidated training event would result in more realistic combat conditions with 

the ability to assess submarine warfare training postures in the Hawaiian Islands Operating Area prior to 

deployment. This training is timed to occur within the HRC because Strike Group skills need to be 

refined and maintained to perform on complex Strike Group scenarios. Only then can mission 

requirements be met. Implementation of the No-Action Alternative is fundamentally inconsistent with 

directives governing the training of naval forces and the responsibilities vested in the Department of the 

Navy for readiness of naval forces, including in the area of undersea warfare. 


3.0 Affected Environment 

3.0 AFFECTED ENVIRONMENT 

This chapter describes existing conditions and the environment at each location that may be affected by 

Alternatives 1 and 2, and the No-Action Alternative. Information is provided to serve as a baseline from 

which to identify and evaluate changes that may result from proposed activities. Sources of data in this 

section include existing reference materials such as EAs, EISs, installation master plans, personal 

contacts, and other published sources. 

The affected environment was initially evaluated in terms of 11 resource areas: air quality, airspace, 

biological resources, cultural resources, geology and soils, hazardous materials and waste, land use, noise, 

safety and health, socioeconomics, and water resources. The exercises proposed for USWEX are a part of 

the ongoing training operations routinely carried out at the proposed USWEX locations. Existing 

environmental documentation prepared for these same training exercises and locations were reviewed to 

determine if there was a potential for impact relative to the 11 resource areas. Based on that review, 

USWEX would have no significant impact on air quality, geology and soils, hazardous materials and 

waste, socioeconomics, and water resources. Air quality impacts would be limited to temporary, shortterm 

vehicle emissions from vehicles used during AMPHIBEX. These emissions would be minor and are 

considered mobile sources. Geology and soils impacts would be limited to short-term minor disturbance 

of beach sand along existing AMPHIBEX access routes. Movement from the beach would also result in 

minor, short-term disturbance to pre-defined access routes. Ordnance impacts during a GUNEX and 

STWEX would result in localized soil disturbance within an existing impact area. Any hazardous 

materials used and waste generated would be managed in accordance with State and federal requirements. 

The USWEX Letter of Instruction will define specific responsibilities regarding implementing the 

procedures required to meet these requirements for managing hazardous waste generated during a 

USWEX. There is very little opportunity for economic interaction during a USWEX. With respect to 

socioeconomics, personnel involved in USWEX would be transient and primarily living aboard the 

surface and submarine vessels and therefore, not create a significant long-term population or housing 

growth increase. However, while briefly in-port during the exercise, expenditures by transient military 

personnel either before or after a USWEX would have a minor positive direct effect on the local economy 

through the purchase of goods and services. Water resources would not be impacted by AMPHIBEX 

activities. Primary surface water features are defined as off-limits during the training exercises, and the 

exercises do not impact groundwater. Ordnance impacts from GUNEX and STWEX would not affect the 

minimal water resources at the USWEX locations. 

Six resource areas were determined to have potential impacts and are included in the USWEX EA/OEA: 

airspace, biological resources, cultural resources, land use, noise, and safety and health. Each resource 

area is discussed for each location unless the proposed activities at that location, based on past analyses, 

would not result in an impact. Table 3-1 provides a summary of resource areas addressed at each location 

in this document. Underwater noise is included in the Biological Resources section. The data presented 

are commensurate with the importance of the potential impacts in order to provide the proper context for 

evaluating impacts. Environmental Justice was also considered, and Chapter 4 includes a section that 

considers potential disproportionate environmental and health impacts to low-income and minority 

groups. 

Aircraft operations that support USWEX are assumed to be supported by the ships involved in the 

USWEX (helicopter and strike warfare aircraft). Operations by P-3 aircraft would originate out of Marine 



Corps Base Hawaii . The use of P-3 aircraft would be part of ongoing training activities for the P-3 wing 

at Marine Corps Base Hawaii. In addition, a limited number of aircraft operations could occur at Hickam 

Air Force Base. These activities are a part of the ongoing exercise ground support operations at Hickam 

Air Force Base. No impacts from these types of operations have been attributed to specific USWEX-type 

activities, and the number of aircraft operations at Hickam Air Force Base would be within operational 

guidelines. Therefore, aircraft ground support operations have not been addressed in this document. 

Table 3–1. USWEX Resource Area Summary 

Affected Environment 

Resource Area 

Airspace 

Biological Resources 

Cultural Resources 

Land Use 

Noise (air borne) 

Safety and Health 

Pacific Missile Range Facility, Kauai x x x x 

Marine Corps Training Area Bellows, 

Oahu 

x x x x x 

Kaula x x x x 

Pohakuloa Training Area, Hawaii x x x x x 

Ocean Areas x x x 

3.1 PACIFIC MISSILE RANGE FACILITY (PMRF), KAUAI 

Amphibious landings at PMRF occur at Majors Bay landing beach, located south of the Main Base and 

about 1,000 ft north of the PMRF housing area. The landing beach is used for large-scale amphibious 

training by ATF and Marine Expeditionary Unit elements. Once ashore, there is no adjacent maneuver 

area, resulting in limited training value. Figure 3-1 shows the location of the landing area at Majors Bay 

in relationship to other facilities on base. 

3.1.1 Airspace—PMRF, Kauai 

The special use airspace in the PMRF region of influence (Figure 3-2) consists of Restricted Airspace 

R-3101, which lies immediately above PMRF and to the west of Kauai, portions of Warning Area W-188 

north of Kauai, and Warning Area W-186 southwest of Kauai, all controlled by PMRF. 

The airfield at PMRF serves as a heliport and a training facility for fixed-wing landings and takeoffs. 

PMRF is located in Class D controlled airspace (2,500-ft ceiling) that is used for airspace overlying 

airports that have an operational control tower. Class E airspace adjoins the Class D airspace to the north, 

south, and east with a floor 700 ft above the surface (Figure 3-2). The adjacent airspace beyond 4 miles is 

international airspace designated for Special Use as Warning Area W-188. It is controlled by Honolulu 




Nohili Ditch 

Kauai, HI 

Kamokala Magazines 

Pacific Ocean 

PMRF Main Base 

Majors Bay 

Beach 

Landing Area 

PMRF Housing 

EXPLANATION 

Roads 

Air Runway 

PMRF Installation Boundary 

Existing Structures 

0 0.5 1 2 Kilometers 

AMPHIBEX Staging Area 

AMPHIBEX Training Beach Area 

Land 


(AMPHIBEX) Areas - 

Pacific Missile Range 

Facility (PMRF) 

Kauai, Hawaii 

North 

0 0.5 1 2 Miles 

Figure 3-1 

060530_AMPHIBEX.eps 

October 2007 

USWEX EA/OEA 

3-3 

3-3


Niihau 

Kaula 

Kauai 

Oahu 

Molokai 

Lanai 

Kahoolawe 

Maui 

Hawaii 

Warning Area 

W-188 Rainbow 

The Hawaiian Islands 

Warning Area 

W-188 

Warning 

Area 

W-189 

R-3101 

V15 

Class E 

Airspace 

Pacific Missile 

Range Facility 

Lihue 

Class E 

Airspace 

V16 

W-186 

Niihau 

Class D 

Airspace 

Kauai 

Class D 

Airspace 

W-187 

R-3107 

Warning Area 

W-186 

Class E 

Airspace 

V15 

V16 

Kaula 

Source: Environmental Systems Research Institute (ESRI) AVDAFIF, 2006 

V12 

EXPLANATION 

Airways 

Warning Areas 

Land 

Airspace Use 

Surrounding Pacific 

Missile Range Facility 

Airport Airspace 

Restricted Airspace 



North 

0 5 10 20 Nautical Miles Figure 3-2 

060530_PMRFAirSpace.eps 



Combined Center Radar Approach Control on behalf of PMRF for a variety of weapons-testing exercises, 

including missile launches. Under agreement with the Federal Aviation Administration (FAA), the 

PMRF Range Safety Officer is solely authorized and responsible for administering range safety criteria, 

surveilling and clearing the range, and issuing firing orders. (Pacific Missile Range Facility, Barking 

Sands, 1998) 

Although relatively remote from the majority of jet routes that crisscross the Pacific Ocean (Figure 3-3), 

the airspace in the PMRF area includes two Instrument Flight Rules en route low altitude airways used by 

commercial air traffic. The most pertinent one to PMRF is V15, which passes east to west through the 

southernmost part of Warning Area W-188 (Figure 3-2). There is a high volume of sightseeing helicopter 

traffic in the region, although none of them fly over PMRF and its Restricted Airspace. (Pacific Missile 

Range Facility, Barking Sands, 1998) 

3.1.2 Biological Resources—PMRF, Kauai 

The broad, white, sandy beach fronting Majors Bay supports only sparse littoral vegetation. Thickets of 

kiawe (Prosopis pallida) and koa haole (Leucaena leucocephala) occupy the northern half, and some 

long-thorn kiawe (Prosopis juliflora) and patches of agave (Agave sisalana) are scattered along the beach 

front. Patches of native Dodonaea-Vitex scrub exist on the southern half. The nearest proposed or 

designated endangered species critical habitat is located approximately 850 ft northwest and 3,600 ft 

southeast of the proposed amphibious landing location. This potential lauèhu (Panicum niihauensis) 

critical habitat is designated as unoccupied critical habitat. 

Migratory shorebirds and seabirds that use the beach are among 39 bird species that have been observed 

throughout PMRF. No threatened or endangered terrestrial species have been recorded within the 

amphibious landing site. The endangered Newell's shearwater (Puffinus auricularis newelli) may over fly 

the training area at night during the April–November breeding season (Pacific Missile Range Facility, 

Barking Sands, 1998). The endangered Hawaiian hoary bat (Lasiurus cinereus semotus) may forage in 

the area. 

Green sea turtles (Chelonia mydas), a species listed as threatened under the federal ESA and listed as 

endangered by the State of Hawaii, infrequently nest on the beach at PMRF. One turtle nest was 

discovered on the southern portion of PMRF in 1985 (Pacific Missile Range Facility, Barking Sands, 

1998). During a 1990 survey of the shoreline of PMRF, approximately 32 green sea turtles were 

observed. In 1999, two nests and four indications of further nesting activities were observed in the Nohili 

ditch area, approximately 3.5 miles north of the proposed amphibious exercise area. There is no 

indication of any nesting activity in recent years. Although green sea turtles may haul out at various 

points along the PMRF beach, they frequently haul out at the Nohili Ditch outfall when it is flowing, and 

feed on attached growths adjacent to the outfall (Burger, personal communication, 2005). 

The endangered Hawaiian monk seal (Monachus schauinslandi) occasionally occurs in the waters 

fronting the Majors Bay beach landing area. Monk seals have been observed to haul out occasionally on 

PMRF beaches. A Hawaiian monk seal gave birth on a PMRF beach approximately 1 mile north of the 

proposed amphibious exercise area in 1999 (Pacific Missile Range Facility, 1999). 


V7 



A331 

R464 

R463 


Pacific Missile 

Range Facility 

V15 

Kauai 



V13 

R465 

V17 

V16 

V25 

Kaula 

V12 

Niihau 

Oahu 

Molokai 

V8 

R576 

R577 

V4 

V2 

V24 

V7 

V1 

V6 

Maui 

V11 

R578 

V5 

B580 

V23 

V21 

V20 

V3 

V22 


Hawaii 

B595 

A579 

Source: National Geospatial Intelligence Agency, 2006 

B596 

G347 

EXPLANATION 

Air Traffic Services Routes 

Oceanic Routes 

High and Low Altitude 

Airways 

Installation Areas 

Land 

North 



0 25 50 100 Nautical Miles Figure 3-3 

060530_HI Airways.eps 

3-6 



3.1.3 Cultural Resources—PMRF, Kauai 

Cultural resources are prehistoric and historic sites, structures, or places with evidence of human activity 

that are significant to a community, culture, or ethnic group. Cultural resources considered to be 

significant for scientific, traditional, or religious reasons, and which meet one or more criteria for 

eligibility to the National Register of Historic Places under the National Historic Preservation Act, are 

historic properties. 

The U.S. Navy prepared a Cultural Resources Management Overview Survey of PMRF to establish an 

inventory of cultural resource properties (U.S. Department of the Navy, 1996). Since the preparation of 

this survey, the U.S. Navy has conducted a Phase I archaeological survey of the installation’s unsurveyed 

areas, and a historic resources survey that includes Cold War properties. 

PMRF has an Integrated Cultural Resources Management Plan (Pacific Missile Range Facility, 2005) 

that provides for a coordination process among the installation, regulatory agencies, and the public that 

helps ensure proper management of the installation’s cultural resources (U.S. Department of Defense 

Instruction 4715.3, Environmental Conservation Program). The U.S. Navy is establishing a 

Programmatic Agreement with the State Historic Preservation Officer to address long-term PMRF 

activities. 

No cultural resource sites have been recorded in the Majors Bay landing and staging areas. The beach 

area has a low potential for discovery of cultural resources and human remains. One documented cultural 

site is located adjacent to the overnight area inland of the beach. This site is thoroughly marked in the 

field, and should be easily recognized as an area excluded from use during exercise activities. 

3.1.4 Safety and Health—PMRF, Kauai 

PMRF Range Control is charged with surveillance, clearance, and real-time range safety. PMRF uses 

Range Commanders Council (RCC) Standard 321-97, Common Risk Criteria for National Test Ranges. 

RCC 321-97 sets requirements for minimally acceptable risk criteria to occupational and nonoccupational 

personnel, test facilities, and non-military assets during range operations. Portions of the 

airspace in the vicinity of the amphibious landing beach are subject to management under Warning Area 

W-188 (see Airspace). In addition, the area of ocean about 1,640 ft offshore falls within the aircraft 

Accident Potential Zone located on the south approach of the airfield. (Pacific Missile Range Facility, 

Barking Sands, 1998) 

3.2 MARINE CORPS TRAINING AREA BELLOWS (MCTAB) 

USWEX exercises conducted at MCTAB include AMPHIBEX as described in Chapter 2.0. MCTAB is a 

1,568-acre military reservation on the southeast coast of Oahu (Figure 3-4). The inactive airfield in the 

center of the site is limited to rotary wing activity, and is occasionally used for U.S. Marine Corps 

helicopter training. About 387 acres of the airfield were converted to expand space available for ground 

and aviation training, offering sufficient area for company-sized amphibious exercises to train for the 

transition from beach landings to combat ashore. (U.S. Pacific Command, 1995) 




KEOLU DR 

Auke 

Kamahele St 

Lapa Pl 

Fire Rd 

Kiukee 

Pl Pl 

Keolu D Dr 

Akamai St St 

Akuila 

Pl 

Oahu, HI 

Akaakaawa St 

Akumu St 

Kahili St 

Holoholo St St 

Akahai St 

Paukiki St 

Kanapuu Dr 

Aupupu u 

St 

Kahako St 

Alahaki ahaki St 

Auwaiku St 

Manulania St 

Aulepe e St St 

Hele St 

Hui St 

Nanialii alii St St 

Aukele St 

Kaluli St 

TA-3 

Loho Loho 

St St 

Humuula St St 

Onioni St 

Lekeona St 

Kuuna Pl 

Kina St 

Kuuna St 

Kupau St 

Family Circle Rd 

Beachwalk St 

Jetty Pl 

Kalanianaole Hwy 

Tinker Rd 

Waimanalo Rd 

Amphibious Landing Zone 

TA-1 

TA-2 

Mahiku Pl 

Flamingo St 

Kumuhau St 

Mahailua St 

72 

Humuniki St 

Humupaa St 

Mekia St 

Poalima St 

Kakaina St 

Hughes Rd 

Moole St 

Inoaole St 

Inoa St 

Everetts Rd 

EXPLANATION 

Roads 

Existing Structures 

Airfield 

Training Areas (TA) 

Installation Boundary 

Land 



North 

0 0.25 0.5 1 Kilometers 

0 0.25 0.5 1 Miles 

Oahu, Hawaii 

Figure 3-4 

060530_Marine Bellows.eps 

3-8 



In addition to USWEX, amphibious landing exercises occur routinely at MCTAB during about 2 weeks 

of each quarter. LCACs and AAVs can exit the beach area via a concrete ramp and cross Tinker Road. 

This transit corridor allows the amphibious units to continue their training in other areas of MCTAB. 

(U.S. Pacific Command, 1995) 

3.2.1 Airspace—MCTAB, Oahu 

Airspace requirements for MCTAB are minimal because aviation is limited to rotary wing activity. Two 

Takeoff Safety Zones and Approach-Departure Clearance Surfaces are delineated over the runways and 

do not extend off-base. In addition, there are two water drop zones that are suitable for helicopter, 

parachute, and helicast training. These areas are designed to avoid over-flights of inhabited areas and 

wildlife sanctuaries. (U.S. Pacific Command, 1995) 

3.2.2 Biological Resources—MCTAB, Oahu 

Vegetation at MCTAB was surveyed in 1994 for the Bellows Air Force Station Land Use and 

Development Plan EIS (U.S. Pacific Command, 1995). Major plant communities include ironwood 

forest, koa haole/christmasberry shrublands, mixed introduced forest, and wetlands. All of the plant 

communities are dominated by introduced species, and exhibit signs of human and grazing-animal 

disturbance. No plant species listed as threatened or endangered under the federal ESA were identified 

during the survey, and none are expected to occur at MCTAB. Only 12 percent of the species recorded 

were native species. Three endemic, but not sensitive or rare, species were identified: ko’olo’olau 

(Bidens sandvicensis), kauna’oa (Cuscuta sandwichiana), and nama (Nama sandwicensis) (U.S. Pacific 

Command, 1995). 

Waimanalo Stream and Inoaole Stream provide some riparian habitat within MCTAB. No wetlands have 

been delineated at MCTAB. However, five small areas exhibit wetland characteristics. These areas 

provide habitat for many native and migratory birds (U.S. Pacific Command, 1995). The endangered 

Hawaiian black-necked stilt (Himantopus mexicanus knudseni), Hawaiian duck (Anas wyvilliana), 

Hawaiian moorhen (Gallinula chloropus sandvicensis) and Hawaiian coot (Fulica americana alai) have 

been observed at MCTAB (U.S. Army Corps of Engineers, 2005). 

A Coral Reef Ecosystem Management Study prepared for MCBH (December 2002) described the 

offshore areas of MCTAB. From the shoreline to approximately 500 ft seaward, the bottom consists of a 

wide, relatively shallow sandy flat extending from the shoreline. Beyond 500 ft from the shore, the sea 

bottom consists of low-relief fossil coral reef platforms, interspersed between sand flats. According to the 

MCBH Coral Reef Ecosystem Management Study, about 48% of the inner Waimanalo Bay consists of 

hard bottom and the remaining 52% is sandy bottom. Live coral covers about 2% of the inner bay. The 

fringing coral reef that separates the inner Waimanalo Bay from the open ocean contains live coral. The 

threatened green sea turtle and endangered hawksbill turtle and Hawaiian monk seal occur in inshore 

waters, and may occur in higher concentrations near the mouth of Waimanalo Stream. Very infrequently, 

green sea turtles and Hawaiian monk seals may haul out onto the beach. There is no recent historical 

record of sea turtle nesting on the beaches at MCTAB. 

The outer barrier reef crest is an actively accreting coral reef habitat comprised predominantly of the 

genera Pocillopora, Porites, and Montipora. There are two well-defined sand channels that extend from 

the shoreline through the barrier reef to the open ocean beyond. 



Green sea turtles occur frequently in the nearshore water off MCTAB. Also occasionally feeding in these 

waters are hawksbill turtles. Hawaiian monk seals have been sighted in the area. Waimanalo Bay is 

expected to be too shallow for the presence of whales, such as the humpback whale, which winters in the 

Hawaiian Islands. However, it is possible that a humpback whale could occasionally use Waimanalo 

Bay. (U.S. Pacific Command, 1995) 

3.2.3 Cultural Resources—MCTAB, Oahu 

MCTAB has undergone extensive mechanical disturbance through construction activities. This 

disturbance has had a profound effect on the archaeological resources of the area. Only one site with 

surface structural remains exists in the entire region. Over the past 30 years, MCTAB has been subjected 

to numerous archaeological studies. 

Eighteen archaeological sites have been identified at MCTAB (U.S. Pacific Command, 1995). Several of 

these sites are located within the runway complex. Most of the archaeological sites are subsurface 

archaeological remains, including possible burial sites in isolated locations. Archaeological studies at 

MCTAB also have identified several sites that appear to be Traditional Cultural Properties. Many of the 

sites are potentially eligible for listing on the National Register of Historic Places (U.S. Army Corps of 

Engineers, 2005). 

The draft Integrated Cultural Resources Management Plan (U.S. Army Corps of Engineers 2005) 

indicates that large portions of MCTAB have moderate to high probabilities of encountering unrecorded 

Native Hawaiian resources. In particular, the banks of Waimanalo and Inoaole Streams and some 

sections of beach dunes are areas of high sensitivity. An excavation at a former waste disposal site 

adjacent to the northern end of the amphibious landing beach, however, yielded no artifacts of traditional 

Hawaiian manufacture (U.S. Air Force, 15 th Airlift Wing, 2005). 

An EIS prepared for the Bellows Air Force Station land use and development plan determined that 

crossing Waimanalo Stream and other training activities could adversely affect cultural resources. 

Measures identified to mitigate this potential impact include crossing streams only at pre-selected 

locations, restricting vehicle crossings to existing bridges or pre-selected fords with no sensitive 

resources, and selecting stream crossings to avoid known cultural resources deposits. (U.S. Pacific 

Command, 1995) 

3.2.4 Land Use—MCTAB, Oahu 

MCTAB occupies land formerly known as Bellows Air Force Base. The land includes an inactive airfield 

consisting of five inactive runways that are in a deteriorated condition. No aircraft are stationed at 

MCTAB. As shown on Figure 3-4, MCTAB consists of three training areas (TA-1, TA-2, and TA-3). 

MCTAB is utilized for military training activities including amphibious training events that do not 

involve expenditure of live ordnance. The beach along TA-1 is open to the public from noon Friday to 

8:00 a.m. Monday. The northern portion of the beach areas at former Bellows Air Force Base was 

retained as a recreation facility, known as Bellows Air Force Station, for use by service members, their 

families, and other DoD personnel. 



3.2.5 Noise—MCTAB, Oahu 

Noise is any sound that is undesirable because it interferes with communication, is intense enough to 

damage hearing, diminishes the quality of the environment, or is otherwise annoying. Responses to noise 

can vary according to the type and characteristics of the noise source, the distance between the noise 

source and the receptor, the sensitivity of the receptor, and the time of day. Acceptable noise levels 

depend on the receiving land uses. A continually varying noise level over a given period can be described 

as a single “equivalent” noise level that contains an amount of sound energy equal to that of the actual 

noise level. This equivalent noise level usually is averaged over a 1, 8, or 24-hour period. Noise is 

commonly measured as instantaneous sound levels in units of decibels (dB). Decibels express the 

intensity of a sound, on a logarithmic scale, relative to a standard sound level pressure. Sound 

measurements in air are referenced to a standard of 20 micro-Pascals (μPa) at a distance of 1 meter (m). 

(A Pascal is a standard unit of measure for pressure.) To account for the varying sensitivity of the human 

ear, raw sound level measurements in decibels are weighted according to various scales. A-weighted 

sound levels (denoted as dBA) that de-emphasize low and high frequencies and emphasize mid-range 

frequencies are used to characterize sound levels that are heard especially well by the human ear. The 

range of human hearing extends from approximately 20 dBA (the threshold of hearing) to 120 dBA (the 

threshold of pain). 

Community noise levels typically are evaluated in terms of the energy-equivalent sound level (L eq ). An 

acceptable indoor noise level is 55 dBA, the threshold at which noise interferes with normal daily 

activities. Outdoor noise levels of 65 dBA are acceptable for most residential land uses, based on an 

assumption that the residential building envelope reduces sound levels by approximately 10 dB. Noisesensitive 

land uses, such as schools, hospitals, libraries, and nursing homes, require more protection than 

other land uses from intrusive noise levels. An acceptable outdoor noise threshold for these land uses is 

55 dBA. 

Ambient noise levels at MCTAB are dominated by surf, wind, and highway noise. During the existing 

military training exercises, including beach landing and helicopter operations, the average equivalent 

sound level in adjacent offsite areas is well within daytime residential criteria for noise exposure (55 

dBA). Short-term, intrusive noise from aircraft and landing craft operations, however, can substantially 

exceed the average ambient noise level. 

In particular, noise from night helicopter operations was determined to have a significant impact on 

nearby residents (U.S. Pacific Command, 1995). Sensitive noise receptors exist in Waimanalo residential 

neighborhoods adjacent to MCTAB. Mitigation measures identified for implementation of the land use 

and development plan included restricting helicopter operations after 10:00 p.m. and retaining noise 

easements on Air Force Station lands declared to be excess. Also, helicopters arriving to and departing 

from the MCTAB airfield arrive from the east and depart to the west, primarily over the ocean, to avoid 

noise impacts on Waimanalo. 



3.3 KAULA 

USWEX activities conducted at Kaula include GUNEX and STWEX, as described in Section 2.2.2. 

Kaula comprises approximately 108 acres used by the U.S. Navy for aircraft gunnery and inert ordnance 

target practice. The rock islet is located 35 km southwest of Niihau. The ordnance impact area is limited 

to about 10 acres at the southeastern tip of the island. The island is not inhabited, and there are no 

manmade structures except for some targets, which are periodically replaced (U.S. Marine Corps, 2002). 

Public access to the island is restricted. (Pacific Missile Range Facility, Barking Sands, 1998) 

3.3.1 Airspace—Kaula 

The island of Kaula encompasses two special use airspace areas: Restricted Airspace R-3107 over Kaula 

and Warning Area W-187 surrounding the island (Figure 3-2). Both areas are controlled by the Honolulu 

Combined Center Radar Approach Control on behalf of FACSFAC Pearl Harbor. 

3.3.2 Biological Resources—Kaula 

Low-growing shrubs and herbs belonging to a semi-arid and strand flora dominate the vegetation on 

Kaula, due to the strong, dry, continuous winds. A few koa haole have been observed on the island. The 

vegetation composition includes 5 endemic (Hawaii only) species, 10 indigenous species, and 14 

introduced (exotic) species. None of the species of plants known to occur on Kaula are listed as 

endangered or threatened (Pacific Missile Range Facility, Barking Sands, 1998). 

According to the State Land Use Classification, Kaula is within a conservation use district protective 

subzone listed as a seabird sanctuary (Pacific Missile Range Facility, Barking Sands, 1998). Twenty-six 

different species of seabirds have been observed on Kaula. These birds include three species of migratory 

shorebirds that occasionally stop on Kaula and six species of exotic (introduced) land birds found on the 

island in small numbers. None of these species is listed as endangered or threatened (Pacific Missile 

Range Facility, Barking Sands, 2002). However, four species designated as Birds of Conservation 

Concern by the U.S. Fish and Wildlife Service nest on the island: black-footed albatross (Diomedea 

nigripes), Laysan albatross (Diomedea immutabilis), Christmas Island shearwater (Puffinus nativitatis), 

and blue-gray noddy (Procelsterna cerulea). Monk seals (Monachus schauinslandi) reportedly haul out 

on the eastern side of the island (U.S. Department of the Navy, 2001a). 

Kaula Banks around Kaula supports some of the best-developed coral reefs in the main Hawaiian Islands. 

The entire Bank has been identified as a habitat of concern. Monk seals (Monachus schauinslandi) have 

been reported hauled out on the east side of the island. (U.S. Department of the Navy, 2001a) 

The humpback whale occurs seasonally in the ocean waters off Kaula. The species is federally listed as 

endangered and is also protected under the Marine Mammals Protection Act. Four consecutive National 

Marine Fisheries Service humpback whale surveys conducted between 1976 and 1979 established that the 

humpback whale occurs in the nearshore waters of Kaula during the winter season on an annual basis 

(Pacific Missile Range Facility, Barking Sands, 1998). 



Three species of sea turtles (hawksbill [Eretmochelys imbricata], green, and loggerhead [Caretta caretta] 

sea turtles, Appendix A) are known to occur in Hawaiian waters and may be present around Kaula. All 

three are listed as threatened or endangered species (Pacific Missile Range Facility, Barking Sands, 

1998). 

3.3.3 Cultural Resources—Kaula 

No evidence exists of extensive human habitation of Kaula, although some evidence of visitation was 

noted during a 1976 survey by a State of Hawaii archaeologist. References to Kaula have been noted in 

Hawaiian oral traditions. No confirmed historic resources exist on the island. No sites on Kaula have 

been designated as State or federal historic places, as defined in EO 11593, Protection and Enhancement 

of the Cultural Environment (Pacific Missile Range Facility, Barking Sands, 1998). Kaula was surveyed 

for archaeological resources in 1999. Six archaeological sites were found on the northern portion of the 

island. No sites were found on the southern portion of the island, inside the impact area. Due to the 

presence of unexploded ordnance, only a small portion of the impact area could be surveyed (Pacific 

Missile Range Facility, Barking Sands, 1998). 

3.3.4 Safety and Health—Kaula 

The primary safety and health concern associated with Kaula is the aerial inert bombing impact area; no 

other hazardous operations occur on the island. To minimize health and safety risks, a Surface Danger 

Zone surrounding Kaula was established for the primary purpose of ensuring an adequate margin of 

safety to non-participating personnel and equipment during gunnery training operations. (Pacific Missile 

Range Facility, Barking Sands, 1998) The Kaula Danger Zone is defined as the waters within a circular 

area with a radius of 5 km (3 miles) having its center on Kaula at latitude 21° 39’ 30”, longitude 160° 32’ 

30” (Pacific Missile Range Facility, Barking Sands, 1998). In addition, because of the potential for 

unexploded ordnance on and just below the surface of the island and adjacent waters, the island and tidal 

shoreline are not open to unauthorized personnel. Prior to any air-to-surface activities, an aircraft flies 

over the island and determines if the area is clear of non-participants and marine mammals before 

conducting the training. If the area is not clear, then the operation is cancelled and the presence of nonparticipants 

is reported to the Coast Guard. (Pacific Missile Range Facility, Barking Sands, 1998) 

The U.S. Navy opens the Surface Danger Zone for fishing on weekends and holidays in accordance with 

33 CFR § 165.1406. The Commander Fleet Air Hawaii, as the controlling and scheduling agency for the 

military use of Kaula, is responsible for notifying the State of Hawaii Department of Land and Natural 

Resources, Division of Fish and Game, State of Hawaii, and Commander Fourteenth Coast Guard 

District, in writing, of the period of time the Surface Danger Zone will be opened for fishing (Pacific 

Missile Range Facility, Barking Sands, 1998). These agencies then make official notifications to the 

public. 

For special operations, multi participants, or hazardous weekend firings, PMRF and FACSFAC Pearl 

Harbor publish dedicated warning Notices to Airmen (NOTAMs) and Notices to Mariners (NOTMARs). 



3.4 POHAKULOA TRAINING AREA (PTA), HAWAII 

USWEX exercises at PTA include STWEX air to ground exercise activities as described in Chapter 2.0. 

The STWEX occurs within the impact area shown in Figure 3-5. 

PTA is a sub-installation of Schofield Barracks (U.S. Pacific Command, 1995). It is located near the 

center of the island of Hawaii in the Humuula Saddle between three volcanoes: Mauna Kea, Mauna Loa, 

and Hualalai. The training area is located on a roughly hexagonal tract of land that extends 15 miles from 

north to south and 17 miles from east to west. Its total area is approximately 108,800 acres (U.S. Army 

Garrison, Hawaii and U.S. Army Corps of Engineers, 1997). 

The mission of PTA is to provide training of full-scale live firing exercises for the 25 th Infantry Division 

(Light), U.S. Army Garrison, Hawaii. PTA also provides training facilities for other branches of the U.S. 

military and friendly foreign forces. As a designated major training area, the training area provides a 

regional location where units from local training areas in the Pacific Rim can build on their home-station 

training. To operate and support the training of various DoD branches, training units of up to 2,500 

personnel are assigned to PTA, usually for a 3- or 4-week rotation. PTA accommodates combined 

air/ground live-fire exercises not possible anywhere else in Hawaii. (U.S. Pacific Command, 1995) 

3.4.1 Airspace—PTA, Hawaii 

The airspace in the PTA region of influence includes uncontrolled Class G airspace, which extends from 

the surface to a ceiling of 1,200 ft, and controlled Class E airspace, which is airspace above 1,200 ft 

unless the special use airspace, discussed below, is activated. Bradshaw Army Airfield is surrounded by 

Class D airspace extending from the surface to a ceiling of 8,700 ft. (U.S. Army 2004). Commercial 

aviation routes are approximately 16 miles from PTA. 

The R-3101 restricted area (Figures 1-1 and 3-5) lies above the PTA, extending from the surface to 

30,000 ft. The effective altitude is from the surface to 30,000 ft; time of use is intermittent by NOTAM 

12 hours in advance; and the controlling agency is Honolulu Combined Center Radar Approach Control. 

When R-3103 is active, Bradshaw Army Airfield Tower maintains control of a corridor of airspace for 

aircraft arriving or departing Bradshaw Army Airfield and PTA. Aircraft operating outside this corridor 

must coordinate with Range Control to enter or exit the airspace and to obtain specific routes for flights 

within Restricted Airspace R-3103 (U.S. Army Garrison, Hawaii, 1996). When the airspace is scheduled 

to be inactive, the agency releases it back to the Honolulu Combined Center Radar Approach Control, 

and, in effect, the airspace is no longer restricted. (U.S. Army, 2004) 

Although there are no formal, published military training routes on the island of Hawaii, the R-3103 

restricted area is used for helicopter training exercises, with an average of 900 aircraft movements per 

month, 99 percent of which involve helicopters. Typical training involves the use of 10 rotary winged 

aircraft at any one time. During deployment training one or two C-130s would be involved about twice a 

year. (U.S. Army, 2004) 




200 

Hawaii, HI 

TA-20 

TA-16 

TA-15 

TA-14 

TA-17 

TA-12 

TA-11 

Bradshaw Army Airfield 

TA-10 

Cantonment Area 

TA-19 

TA-13 

TA-18 

TA-9 

TA-8 

TA-7 

TA-6 

TA-22 

RNG-14 

RNG-12 

RNG-11T 

RNG-10 

TA-5 

TA-3 

TA-4 

TA-1 

TA-2 

TA-21 

TA-21 

Impact Area 

RNG-1 - Attack 

TA-23 

EXPLANATION 

Roads 

Special Use Airspace: R-3103 

Impact Area 

Land 

Pohakuloa Training 

Area 

North 

Bradshaw Army Airfield 

Cantonment Area 


0 1.25 2.5 5 Miles 

RNG = Range 

TA = Training Area 


Hawaii, Hawaii 

Figure 3-5 

060530_Pohakuloa TA.eps 

October 2007 USWEX EA/OEA 

3-15 

3-15


3.4.2 Biological Resources—PTA, Hawaii 

PTA was surveyed for biological resources in 1997. Ten distinct habitats were identified during this 

baseline assessment, five of which are considered rare by the Hawaii Natural Heritage Program. Many 

native plant and animal species in the area are rare or endangered. Many of the species occurring in PTA 

are unique to the island of Hawaii. Several exist only in the Saddle Region surrounding PTA, while 

others are specific to PTA itself (U.S. Army Garrison, Hawaii and U.S. Army Corps of Engineers, 

1998a). A unique cave system harbors many wildlife species that may be endemic or unique. The area 

has been disturbed by an influx of weedy alien vegetation and feral animals, particularly ungulates such 

as goats and sheep. 

The Impact Area is an isolated, central portion of PTA. The Impact Area has not been surveyed in detail 

due to the hazard posed by unexploded ordnance. Helicopter fly-overs have identified several native taxa 

and natural areas within the Impact Area (U.S. Army Garrison, Hawaii and U.S. Army Corps of 

Engineers, 1997). 

PTA supports extensive populations of rare plants, in spite of extensive habitat damage caused by 

introduced species. Most of the vegetation consists of native plants, primarily elements of the Subalpine 

Dryland plant community. Twenty-one rare plant species with federal status have been identified. 

Thirteen of these species are listed under the federal ESA. Five species are considered critically 

endangered, of which two are known to exist only within PTA. Federally listed endangered and 

threatened plant species found in PTA are listed in Appendix A. 

PTA supports an abundant avian fauna, including the common àmakihi (Hemignathus virens), Ììwi 

(Vestiaria coccinea), and àpapane (Himatione sanguinae). Eight rare animal species are known to 

inhabit PTA, of which six are birds listed as endangered under ESA. The endangered Hawaiian hoary bat 

(Lasiurus cinereus semotus) and a rare land snail also are found in PTA. Federally listed endangered and 

threatened wildlife found in PTA are listed in Appendix A. 

3.4.3 Cultural Resources—PTA, Hawaii 

Recent archaeological surveys have identified 250 known archaeological sites at PTA. Most of these are 

subterranean lava tubes, which are concentrated in the western portion of the training area. Other 

identified sites include a habitation cave, platforms and shrines, ahus (rock pile sites), trails, lithic quarries 

and workshops, rock walls, and an open-air shelter. Most of the 250 sites are related to traditional native 

Hawaiian history and would be considered significant under the National Historic Preservation Act 

(Criterion D) due to research potential. Protective measures for cultural resources were addressed in the 

Ecosystem Management Plan Report for Pohakuloa Training Area (U.S. Army Garrison, Hawaii and 

U.S. Army Corps of Engineers, 1998b). 

As of 2001, an estimated 30 percent of the PTA had been surveyed for archaeological sites. The current 

archaeological management areas are known sites. No archaeological sites have been identified within 

the impact area. There are two known caves west of Redleg Trail within the impact area (U.S. Army 

Garrison, Hawaii and U.S. Army Corps of Engineers, 1998b). 



3.4.4 Noise—PTA, Hawaii 

PTA is located in a rural area where, in the absence of military training activities, the background noise 

level is low. Based on the Stryker Brigade Final EIS (U.S. Army 2004), the dominant noise sources at 

PTA include military aircraft (mostly helicopters), military vehicle traffic, and ordnance use during live 

fire and other training exercises. Areas with sound levels above 75 dBA are contained within the present 

boundaries of PTA. Areas with sound levels of 65-75 dBA affect Bradshaw Army Airfield and the 

western portion of the cantonment area. These noise conditions extend beyond the boundaries of PTA 

from Bradshaw Army Airfield westward to the northwest corner of the post. Except for the cantonment 

area, no noise-sensitive land uses are affected by existing noise conditions that exceed 65 dBA. 

The U.S. Army is developing an environmental noise management plan that will be used for exploring: 

• Improvements in land use compatibility adjacent and proximal to U.S. Army Garrison Hawaii 

facilities 

• The feasibility of providing increased acoustical insulation to structures or areas where noisesensitive 

receptors may reside, specifically in areas that are or may become exposed to Zone III 

and Zone II noise conditions, with a priority given to family and troop housing areas affected by 

Zone III conditions 

• Ways to improve notification to surrounding communities about the scheduling and nature of 

nighttime training exercises, which are possible sources of complaints about noise and vehicle 

activity—while enhanced public information programs will not reduce actual noise levels, they 

can help reduce the frequency of noise complaints 

The U.S. Army occasionally receives complaints from adjacent land-owners about noise from low-flying 

aircraft and ordnance detonations (U.S. Army, 2004). For ordnance deliveries to the impact area, the 

rental cabins at Mauna Kea State Park and the Kilohana Girl Scout Camp are considered to be noisesensitive 

receptors. These areas are located approximately 3 miles and 6 miles, respectively from the PTA 

impact area. 

3.4.5 Safety and Health—PTA, Hawaii 

The impact area is in an isolated area in the center of PTA with restricted access located away from the 

civilian population (Figure 3-5). Surface danger zones are designated for the ranges at PTA and are 

configured toward the impact area (approximately 51,000 acres) in the central portion of PTA. In 

addition, there is a 16,800-acre cluster bomb impact area within the larger impact area. The ordnance 

impact area and cluster bomb impact area are not accessible. (U.S. Army, 2004) 

Safety and health precautions are covered in the PTA External Standing Operating Procedures and are 

briefed by the PTA Operations Center (U.S. Army Garrison, Hawaii, 1996). The DoD takes every 

reasonable precaution during the planning and execution of the operation of training exercises to prevent 

injury to human life and wildlife, or damage to property. Specific safety plans are developed to ensure 

that each hazardous operation is in compliance with applicable policy and regulations and to ensure that 

the general public and range personnel and assets are provided an acceptable level of safety. 



3.5 OCEAN AREA HAWAIIAN ISLANDS 

Ongoing USWEX activities in the open-ocean area include ASWEX, ASMEX, and GUNEX as described 

in Chapter 2.0. The region of influence for USWEX activities includes the entire Hawaiian Islands 

Operating Area including the Warning Areas and Air Traffic Control Assigned Airspace Areas (ATCAA) 

areas (Figure 1-1). As discussed in the PMRF Enhanced Capability EIS (Pacific Missile Range Facility, 

Barking Sands, 1998) and other related environmental documents, a limited number of resources would 

potentially be impacted, including airspace, biological resources, and safety and health. Open ocean areas 

outside jurisdictional waters of the United States are analyzed per EO 12114. 

3.5.1 Airspace—Ocean Area, Hawaiian Islands 

Areas beyond the territorial limit are defined as international airspace. Therefore, the procedures of the 

International Civil Aviation Organization (ICAO) outlined in ICAO Document 4444, Rules of the Air and 

Air Traffic Services, are followed (International Civil Aviation Organization, 1996; 1997). ICAO 

Document 4444 is the equivalent air traffic control manual to FAA Handbook 7110.65, Air Traffic 

Control. The ICAO is not an active air traffic control agency and has no authority to allow aircraft into a 

particular sovereign nation's Flight Information Region or Air Defense Identification Zone and does not 

set international boundaries for air traffic control purposes. The ICAO is a specialized agency of the 

United Nations whose objective is to develop the principles and techniques of international air navigation 

and to foster planning and development of international civil air transport. 

The FAA acts as the U.S. agent for aeronautical information to the ICAO, and air traffic in the central 

Pacific is managed by the Oakland Air Route Traffic Control Center (ARTCC) within several Oceanic 

Control Sectors. The Radar Control Area that surrounds the Hawaiian Islands is managed by the 

Honolulu Combined Radar Approach Control. 

Most of the airspace utilized during USWEX is in international airspace and air traffic is managed by the 

Honolulu Combined Facility. The Honolulu Combined Facility includes the ARTCC, the Honolulu 

control tower, and the Combined Radar Approach Control (CERAP) collocated in a single facility. 

The special use airspace in the ocean area is shown on Figure 1-1 and consists of Warning Area W-188 

north of Kauai, and Warning Area W-186 southwest of Kauai, controlled by PMRF. Warning Areas W- 

188 Rainbow, W-189 and W-190 north of Oahu, W-187 surrounding Kaula, and W-191, W-192, W-193, 

W-194 and W-196 south of Oahu are scheduled through the Navy Fleet Area Control and Surveillance 

Facility (FACSFAC) Pearl Harbor, which then coordinates with the Honolulu Combined Facility. There 

are also 12 ATCAA areas within the ROI. These ATCAA areas provide additional FAA controlled 

airspace adjacent to and between the Warning Areas. 

Training exercises within the Hawaiian Islands Operating Area are conducted in accordance with 

FACSFAC San Diego Instruction (INST) 3120.1D. This instruction includes a description of each 

operating area within the Hawaiian Islands Operating Area that includes the location, description, type of 

exercises, authorized ordnance, altitude, periods of usage, scheduling authority, communications 

frequencies, and special instructions including protected species considerations and restrictions. 

The Ocean Area airspace has several oceanic routes, as shown on Figure 3-3. Most of the oceanic routes 

enter the ROI from the northeast and southwest, and are generally outside the special use airspace 



warning areas described above. The Air Traffic Services routes are concentrated along the Hawaiian 

Island chain. Most of the open ocean ROI is well removed from the jet routes that currently crisscross the 

North Pacific Ocean. As an alternative to aircraft flying above 29,000 ft following published, preferred 

IFR routes, the FAA is gradually permitting aircraft to select their own routes. This “Free Flight” 

program is an innovative concept designed to enhance the safety and efficiency of the National Airspace 

System. 

Free Flight is already underway, and the plan for full implementation will occur as procedures are 

modified and technologies become available and are acquired by users and service providers. This 

incremental approach balances the needs of the aviation community and the expected resources of both 

the FAA and the users. The Central Pacific Oceanic Program is one of the Free Flight programs 

underway. In the airspace over the Central Pacific, advanced satellite voice and data communications are 

being used to provide faster and more reliable transmission to enable reductions in vertical, lateral, and 

longitudinal separation, more direct flights and tracks, and faster altitude clearances. With the full 

implementation of this program, the amount of airspace in the ROI that is likely to be clear of traffic may 

decrease as pilots, whenever practical, choose their own route and file a flight plan that follows the most 

efficient and economical route. 

Air traffic in the USWEX open ocean area is managed by the Honolulu ARTCC and to a lesser extent the 

Oakland ARTCC. 

3.5.2 Biological Resources—Ocean Area, Hawaiian Islands 

Essential Fish Habitat (EFH)—In 2003, NMFS prepared a detailed description of non-fishing impacts 

to essential fish habitat and recommended conservation measures. Activities that may potentially impact 

EFH were identified as occurring in four discreet ecosystems: upland, riverine, estuarine, and 

coastal/marine systems. Broad categories of such activities include, but are not limited to, mining, 

dredging, fill, impoundment, discharge, water diversions, thermal additions, actions that contribute to 

non-point source pollution and sedimentation, introduction of potentially hazardous materials, 

introduction of exotic species, and the conversion of aquatic habitat that may eliminate, diminish, or 

disrupt the functions of EFH. 

Sound in the Water—As sound travels through water, it creates a series of pressure disturbances. 

Frequency is the number of complete cycles a sound/pressure wave occurs per unit time (measured in 

cycles per second, or hertz [Hz]). Generally speaking for acoustics, frequency is loosely characterized as 

low, medium, or high: 

• Low frequency—Below 1,000 Hz 

• Mid-frequency—From 1,000 Hz to 10,000 Hz 

• High frequency—Above 10,000 Hz 

Animals hear at many different frequencies, which can vary not only between species but also from 

individual to individual. From an acoustical impact perspective, for a marine animal to be affected by 

mid-frequency sound sources it must: 

• Be within the geographic area influenced by the mid-frequency active tactical sonar used 

during USWEX 



• Possess the ability to transduce sound energy into mechanical effects 

Species that did not meet these criteria were excluded from further consideration of acoustic effects in this 

EA/OEA. 

In order for sound to have an effect on an animal, some organ or tissue must be capable of transducing 

sound energy into mechanical effects. To achieve this, the organ or tissue must have an acoustic 

impedance different from water, or an impedance mismatch. Thus, many organisms would be unaffected, 

even if they were in areas with high mid-frequency sound levels, because they do not have significant 

acoustic impedance mismatches or cannot detect mid-frequency sounds. 

These factors immediately limit the types of organisms that could be adversely exposed to mid-frequency 

sound levels. For example, phytoplankton and zooplankton species have no tissues with sufficient 

impedance mismatches from water or sensory perception mechanisms to detect mid-frequencies (the 

sound pulse would essentially pass through them without being detected. Therefore, phytoplankton and 

zooplankton do not have the potential to be physically affected by the operation of mid-frequency active 

tactical sonar and thus are not evaluated further in this EA/OEA. 

3.5.2.1 Benthic Invertebrates 

Invertebrates are not analyzed in this EA/OEA because: 

• They do not have delicate organs or tissues whose acoustic impedance is significantly 

different from water. 

• There is no evidence of auditory capabilities in the frequency range to be used during 

USWEX. 

While some gelatinous plankton do have air-filled bladders, due to their small size they do not have a 

resonance frequency sensitive to the frequencies to be used during USWEX. 

Among invertebrates, only cephalopods (octopus and squid) and decapods (lobster, shrimp, and crab) are 

known to sense sound, but only at low frequencies (Budelman and Young, 1994; Offutt, 1970). There are 

some limited studies indicating that these invertebrates have negligible hearing capability for frequencies 

greater than 1 kHz. Given that the mid-frequency sound used during USWEX is not considered to be in 

the primary hearing register of those invertebrate species that may possess the ability to sense sound, the 

potential for effects is negligible for invertebrate species that may inhabit the area during USWEX. 

Invertebrates, therefore, are not addressed further, from an acoustical perspective, in this document. 

3.5.2.2 Fish 

Behavioral studies have shown that most fish only detect sound up to 1 kHz-3 kHz (1,000 to 3,000 Hz) 

(Popper, 2000). The most sensitive hearing range for most fish is from 100 Hz to 200 Hz. The proposed 

mid-frequency active tactical sonar operations would use mid-frequency sound sources, which range from 

1 kHz (1,000 Hz) to 10 kHz (10,000 Hz). Thus, it is expected that most fish species would only be able 

to detect the USWEX mid-frequency sonar at the lower end of its frequency range. In addition, the 

USWEX mid-frequency sonar would not be within the sensitive hearing range of most fish. It has been 

demonstrated that a few species (i.e., bay anchovy—Anchoa mitchilli; scaled sardine—Harengula 

jaguana; and Spanish sardine—Sardinella aurita) can detect sounds up to about 4 kHz (4,000 Hz) and 



that one species (American shad—Alosa sapidissima) is able to detect sounds up to 180 kHz (180,000 

Hz) (Mann, et al., 2001). 

Broadly, fish can be categorized as hearing specialists (broad hearing frequency range with low auditory 

thresholds) or hearing generalists (narrower frequency range with higher auditory thresholds) (Scholik 

and Yan, 2002). Wysocki and Ladich (2005) investigated the influence of noise exposure on the auditory 

sensitivity of two hearing specialists (goldfish—Carassius auratus and lined Raphael catfish—Platydoras 

costatus) and a hearing generalist (sunfish—Lepomis gibbosus). Baseline thresholds showed greatest 

hearing sensitivity around 0.5 kHz (500 Hz) in the goldfish and catfish and at 0.1 kHz (100 Hz) in the 

sunfish. For the hearing specialists (goldfish and catfish), continuous white noise of 130 dB resulted in a 

significant threshold shift of 23-44 dB. In contrast, the auditory thresholds in the hearing generalist 

(sunfish) declined by 7-11 dB. It was concluded that acoustic communication and orientation of fishes, in 

particular of hearing specialists, may be limited by noise regimes in their environment (Wysocki and 

Ladich, 2005). 

Other studies have also found that fish hearing generalists normally experience only minor or no hearing 

loss when exposed to continuous noise, but that hearing specialists may be affected by noise exposure and 

that acoustic communication might be restricted in noisy habitats (Amoser and Ladich, 2003; Smith, et 

al., 2004 a and b). 

With respect to fish behavior, studies have shown that low frequency noise will alter the behavior of fish. 

For example, research has been conducted on the use of low frequency devices to deter fish away from 

potentially dangerous situations, such as turbine inlets of hydroelectric power plants (Knudsen et al., 

1994). Stronger avoidance responses are exhibited from sounds in the infrasound range (5-10 Hz) than 

from 50 and 150 Hz sounds (Knudsen et al., 1992). In test pools, wild salmon will swim to a deeper 

section of the test pool, even if that deep section was near the sound source, when exposed to low 

frequency sound. In regard to high frequency sound, one behavioral response study demonstrated that 

exposure to broadband biosonar-type sounds (odontocete biosonar is directed forward (different than the 

mid-frequency sonar that would be used during USWEX, however) causes behavioral modification in 

Pacific herring (Wilson and Dill, 2002). 

With respect to mid-frequency sound, research has been conducted on acoustic devices designed to deter 

marine mammals from gillnet fisheries (Gearin et al., 2000; Culik et al., 2001) to ascertain how noise may 

affect fish behavior. These devices generally have a mid-frequency range, similar to the sonar devices 

that would be used during USWEX. Adult sockeye salmon exhibited an initial startle response to the 

placement of inactive acoustic alarms designed to deter harbor porpoise (Gearin et al., 2000). The fish 

resumed their normal swimming pattern within 10 to 15 seconds. After 30 seconds, the fish approached 

the inactive alarm to within 30 centimeters (cm) (1 ft). 

The same experiment was conducted with the alarm active. The fish exhibited the same initial startle 

response from the insertion of the alarm into the tank; however, within 30 seconds, the fish were 

swimming within 30 cm (1 ft) of the active alarm. After 5 minutes of observation, the fish did not exhibit 

any reaction or behavior change except for the initial startle response (Gearin et al., 2000). This 

demonstrated that the alarms were either inaudible to the fish, or the fish were not disturbed by the midfrequency 

sound (Gearin et al., 2000). 



To summarize the results of some of the recent research on fish and acoustics, it is expected that most fish 

species would barely be able to detect the USWEX mid-frequency sonar at the lower end of its frequency 

range. The results of several studies have indicated that acoustic communication and orientation of 

fishes, in particular of hearing specialists, may be limited by noise regimes in their environment. Further, 

some fish may respond behaviorally to varying sound frequencies, including possible mid-frequency 

sources (similar to the sonar sources that would be used during USWEX). Although the potential for 

impact is minimal, fish are included for analysis. 

3.5.2.3 Seabirds 

There are few data on hearing in seabirds and even less on underwater hearing. Studies with other species 

have shown that birds are highly sensitive to low frequency sound in the air. While it is likely that many 

diving birds can hear mid-frequency sound, there is no evidence that seabirds use sound underwater. In 

addition, seabirds spend a very small fraction of their time submerged, and they can rapidly disperse to 

other areas if disturbed. For these reasons, seabirds are not addressed further, from an acoustical 

perspective, in this EA/OEA. 

3.5.2.4 Marine Mammals 

As described in Section 1.2, long-term studies of the quantification and effects of exposure of marine 

mammal species to acoustic emissions are progressing and the U.S. Navy, in coordination with the 

National Marine Fisheries Service (NMFS), is incorporating the results into relevant environmental 

planning analyses and documents. This section includes additional information on marine mammals 

within these areas. 

The information contained in this section relies heavily on the data gathered in the Marine Resource 

Assessment for the Hawaiian Islands Operating Area (U.S. Department of the Navy, Commander, U.S. 

Pacific Fleet, 2005). Bibliographic citations from that document are included in the text to maintain 

readability and to provide the reader with the specific reference used in the original document. Based on 

the Marine Resource Assessment, there are 27 marine mammal species with possible or confirmed 

occurrence in the Hawaiian Islands Operating Area. As shown in Table 3-2, there are 25 cetacean species 

(whales, dolphins, and porpoises) and 2 pinnipeds (seals). In addition, five species of sea turtles are 

known to occur in the Hawaiian Islands Operating Area. 

3.5.2.5 Marine Mammal Occurrence 

The Marine Resource Assessment data were used to provide a regional context for each species. The data 

were compiled from available sighting records, literature, satellite tracking, and stranding and bycatch 

data. The most abundant marine mammals are rough-toothed dolphins, dwarf sperm whales, and Fraser’s 

dolphins, and the most abundant large whales are sperm whales (Barlow, 2003). Each marine mammal 

species is described below with available distribution information. Seven marine mammal species listed 

as federal endangered occur in the area, including the humpback whale, North Pacific right whale, sei 

whale, fin whale, blue whale, sperm whale, and Hawaiian monk seal. Endangered marine mammals are 

presented first in the following text, with the remaining species following the order presented in 

Table 3-2. 



Table 3-2. Marine Mammals that May Occur in the Hawaiian Islands Operating Area 

Order Cetacea Scientific Name Status Occurs 1 Group Detection Probability 3 

Size 2 Group 1-20 Group >20 

Overall 

Abundance 

Suborder Mysticeti (baleen whales) 

Family Balaenidae (right whales) 

North Pacific right whale Eubalaena japonica E Rare 

Family Balaenopteridae (rorquals) 

Humpback whale Megaptera novaeangliae E Regular 1.7 4,005 

Minke whale 

Balaenoptera 

Rare 

acutorostrata 

Sei whale Balaenoptera borealis E Rare 3.4 0.90 0.90 77 

Fin whale Balaenoptera physalus E Rare 2.6 0.90 0.90 174 

Blue whale Balaenoptera musculus E Rare 

Bryde’s whale 

Balaenoptera 

Regular 1.5 0.90 0.90 493 

edini/brydei* 

Suborder Odontoceti (toothed whales) 

Family Physeteridae (sperm whale) 

Sperm whale Physeter macrocephalus E Regular 7.8 0.87 0.87 7,082 

Family Kogiidae (pygmy sperm whales) 

Pygmy sperm whale Kogia breviceps Regular 1.0 0.35 0.35 7,251 

Dwarf sperm whale Kogia sima Regular 2.3 0.35 0.35 19,172 

Family Ziphiidae (beaked whales) 

Cuvier’s beaked whale Ziphius cavirostris Regular 2.0 0.23 0.23 12,728 

Blainville’s beaked whale Mesoplodon densirostris Regular 2.3 0.45 0.45 2,138 

Longman’s beaked whale Indopacetus pacificus Regular 17.8 0.96 0.96 766 

Family Delphinidae (dolphins) 

Rough-toothed dolphin Steno bredanensis Regular 14.8 0.74 1.00 19,904 

Common bottlenose dolphin Tursiops truncatus Regular 9.5 0.74 1.00 3,263 

Pantropical spotted dolphin Stenella attenuata Regular 60.0 0.77 1.00 10,260 

Spinner dolphin Stenella longirostris Regular 29.5 0.77 1.00 2,804 

Striped dolphin Stenella coeruleoalba Regular 37.3 0.77 1.00 10,385 

Risso’s dolphin Grampus griseus Regular 15.4 0.74 1.00 2,351 

Melon-headed whale Peponocephala electra Regular 89.2 0.74 1.00 2,947 

Fraser’s dolphin Lagenodelphis hosei Rare 286.3 0.77 1.00 16,836 

Pygmy killer whale Feresa attenuata Regular 14.4 0.74 1.00 817 

False killer whale Pseudorca crassidens Regular 10.3 0.74 1.00 268 

Killer whale Orcinus orca Regular 6.5 0.90 0.90 430 

Short-finned pilot whale 

Globicephala 

Regular 22.3 0.74 1.00 8,846 

macrorhynchus 

Order Carnivora 

Suborder Pinnipedia (seals, sea lions, walruses) 

Family Phocidae (true seals) 

Hawaiian monk seal Monachus schauinslandi E Regular 

Northern elephant seal Mirounga angustirostris Rare 

Source: U.S. Department of the Navy, Commander, U.S. Pacific Fleet, 2005; Barlow, 2003; Mobley, et al., 2001a 

Notes: 

Taxonomy follows Rice (1998) for pinnipeds and sirenians and the International Whaling Commission (2004) for cetaceans. 

1 

Occurrence: Regular = A species that occurs as a regular or normal part of the fauna of the area, regardless of how abundant or common it is; 

Rare = A species that only occurs in the area sporadically; *includes more than one species, but nomenclature is still unsettled. 

2 Mean group sizes are the geometric mean of best estimates from multiple observers and have not been corrected for bias. 

3 Barlow (2003) 



3.5.2.5.1 Endangered Cetaceans 

Humpback Whale (Megaptera novaeangliae) 

Humpback whales in Hawaiian waters are considered to be from the central North Pacific stock (Angliss 

and Lodge 2004). There are an estimated 4,005 (Coefficient of Variation [CV]=0.095) individuals in this 

stock (Angliss and Lodge, 2004). Estimates from Calambokidis et al. (1997) and Baker and Herman 

(1987) suggest that the stock has increased in abundance. 

Humpback whales utilize Hawaiian waters as a major breeding ground during winter and spring 

(November through April). Peak abundance around the Hawaiian Islands is from late February through 

early April (Mobley et al., 2001a; Carretta et al., 2005). During the fall-winter period, primary 

occurrence is expected from the coast to 50 nm (93 km) offshore, which takes into consideration both the 

available sighting data and the preferred breeding habitat (shallow waters) (Herman and Antinoja, 1977; 

Mobley et al., 1999, 2000, 2001a). The greatest densities of humpback whales (including calves) are in 

the four-island region consisting of Maui, Molokai, Kahoolawe, and Lanai, as well as Penguin Bank 

(Baker and Herman, 1981; Mobley et al., 1999; Maldini 2003). Secondary occurrence is expected from 

seaward of this area, past the Hawaiian Islands Operating Area boundaries. 

The Hawaiian Island Humpback Whale National Marine Sanctuary was signed into law in November 

1992. The Final EIS/Management Plan was released in March 1997, and the final rule was published in 

November 1999. Included as activities allowed within the Sanctuary are all classes of military activities, 

internal or external to the Sanctuary, that are being or have been conducted before the effective date of the 

regulations, as identified in the Final EIS/Management Plan. The sanctuary includes specific areas from 

the coast of the Hawaiian Islands seaward to the 100-fathom isobath. 

North Pacific Right Whale (Eubalaena japonica) 

No reliable population estimate presently exists for this species; the population in the eastern North 

Pacific Ocean is considered to be very small, perhaps only in the tens of animals (National Marine 

Fisheries Service, 2002; Clapham et al,. 2004), while in the western North Pacific Ocean, the population 

may number at least in the low hundreds (Brownell et al., 2001; Clapham et al., 2004). There is no 

proposed or designated critical habitat for the North Pacific right whale in the Hawaiian Islands Operating 

Area. NMFS has recently published the final rule for two areas within the Gulf of Alaska and the Bering 

Sea, designating critical habitat for the North Pacific right whale. 

Right whales occur in sub-polar to temperate waters. The North Pacific right whale historically occurred 

across the Pacific Ocean north of 35 degrees north, with concentrations in the Gulf of Alaska, eastern 

Aleutian Islands, south-central Bering Sea, Sea of Okhotsk, and the Sea of Japan (Omura et al., 1969; 

Scarff, 1986; Clapham et al., 2004). Presently, sightings are extremely rare, occurring primarily in the 

Okhotsk Sea and the eastern Bering Sea (Brownell et al., 2001; Shelden et al., 2005). Prior to 1996, right 

whale sightings were very rare in the eastern North Pacific Ocean (Scarff, 1986; Brownell et al., 2001). 

Recent summer sightings of right whales in the eastern Bering Sea represent the first reliable consistent 

observations in this area since the 1960s (Tynan et al., 2001; LeDuc et al, 2001). 

Historical whaling records provide virtually the only information on North Pacific right whale 

distribution. During the summer, whales were found in the Gulf of Alaska, along both coasts of the 

Kamchatka Peninsula, the southeastern Bering Sea, and in the Okhotsk Sea (Clapham et al., 2004; 

Shelden et al., 2005). Based on migration patterns and whaling data, the Hawaiian Islands may have been 



a breeding ground for North Pacific right whales in the past (Clapham et al., 2004). Therefore, 

occurrence patterns would likely change in this area if the population were to increase substantially. 

There are very few recorded sightings from the Hawaiian Islands; they are from both shallow and deep 

waters (Herman et al., 1980; Rowntree et al., 1980; Salden and Mickelsen, 1999). The highly endangered 

status of this species necessitates an extremely conservative determination of its occurrence (Jefferson, 

personal communication, 2005). Secondary occurrence is expected from the coastline to seaward of the 

Hawaiian Islands Operating Area boundaries. Right whales are not expected to make their way into 

lagoons or busy harbors (Jefferson, personal communication, 2005). Right whale occurrence patterns are 

assumed to be similar throughout the year. 

Fin Whale (Balaenoptera physalus) 

The NOAA stock assessment report recognizes three stocks of fin whales in the North Pacific Ocean: (1) 

the Hawaii stock; (2) the California/Oregon/Washington stock; and (3) the Alaska stock (Carretta et al., 

2005). The best available estimate of abundance for the Hawaiian stock of the fin whale is 174 

individuals (CV = 0.72) (Barlow, 2003; Carretta et al., 2005). 

Fin whales are not common in the Hawaiian Islands. Sightings were reported north of Oahu in May 

1976, the Kauai Channel in February 1979, and north of Kauai during February 1994 (Shallenberger, 

1981; Mobley et al., 1996). Thompson and Friedl (1982) suggested that fin whales migrate into Hawaiian 

waters mainly during fall and winter, based on acoustic recordings off the islands of Oahu and Midway 

(Northrop et al., 1971; McDonald and Fox, 1999). Primary occurrence is expected seaward of the 100 m 

isobath during the fall-winter period to account for possible stragglers migrating through the area. There 

is a rare occurrence of fin whales throughout the Hawaiian Islands during the spring-summer period. 

Sei Whale (Balaenoptera borealis) 

For the NOAA stock assessment reports, sei whales within the Pacific Exclusive Economic Zone (EEZ) 

are divided into three discrete, non-contiguous areas: (1) the Hawaiian stock; (2) California/Oregon/ 

Washington stock; and (3) the Eastern North Pacific (Alaska) stock (Carretta et al., 2005). The best 

available estimate of abundance is 77 sei whales (CV = 1.06) for the Hawaiian Islands EEZ (Barlow, 

2003; Carretta et al., 2005). 

The taxonomy of the baleen whale group formerly known as sei and Bryde’s whales is currently confused 

and highly controversial (see Reeves et al. 2004 for a recent review, also see the Bryde’s whale species 

account in Section 3.5.2.2.3 for further explanation). 

Sei whales spend the summer months feeding in the subpolar higher latitudes and return to the lower 

latitudes to calve in winter. 

The sei whale is considered to be rare in Hawaiian waters based on reported sighting data and the species’ 

preference for cool, temperate waters. Secondary occurrence is expected seaward of the 3,000 m isobath 

on the north side of the islands only. This pattern was based on sightings made during the NMFS– 

Southwest Fisheries Science Center shipboard survey assessment of Hawaiian cetaceans (see Barlow et 

al. 2004). Sei whales are expected to be rare throughout the remainder of the Hawaiian Islands Operating 

Area. Occurrence patterns are expected to be the same throughout the year. 



Blue Whale (Balaenoptera musculus) 

Acoustic data suggest that there are two stocks: the western North Pacific stock (that includes Hawaii) 

and the eastern north Pacific stock (Stafford et al., 2001; Stafford, 2003). No estimate of abundance is 

available for the western North Pacific stock of the blue whale (Carretta et al., 2005). 

Blue whales are distributed from the ice edges to the tropics in both hemispheres (Jefferson et al., 1993). 

Blue whales as a species are thought to summer in high latitudes and move into the subtropics and tropics 

during the winter (Yochem and Leatherwood, 1985). Data from both the Pacific and Indian Oceans, 

however, indicate that some individuals may remain in low latitudes year-round, such as over the Costa 

Rican Dome (Wade and Friedrichsen, 1979; Reilly and Thayer, 1990). 

Blue whales belonging to the western North Pacific stock appear to feed during summer southwest of 

Kamchatka, south of the Aleutians, and in the Gulf of Alaska (Stafford, 2003; Watkins et al., 2000), and 

in winter they migrate to lower latitudes in the western Pacific Ocean and less frequently in the central 

Pacific Ocean, including Hawaii (Stafford et al., 2001; Carretta et al., 2005). 

The only (presumably) reliable sighting report of this species in the central North Pacific Ocean was a 

sighting made from a scientific research vessel about 400 km northeast of Hawaii in January 1964 

(National Marine Fisheries Service, 1998). 

There is a rare occurrence for the blue whale throughout the year throughout the entire Hawaiian Islands 

Operating Area. Blue whale calls have been recorded off Midway and Oahu (Northrop et al., 1971; 

Thompson and Friedl, 1982; McDonald and Fox, 1999); these provide evidence of blue whales occurring 

within several hundred kilometers of these islands (National Marine Fisheries Service, 1998). The 

recordings made off Oahu showed bimodal peaks throughout the year, suggesting that the whales were 

migrating into the area during summer and winter (Thompson and Friedl, 1982; McDonald and Fox 

1999). The greatest likelihood of encountering blue whales would be in waters with depths greater than 

100 m, based on observations in locales that blue whales are seen regularly (e.g., Schoenherr, 1991). 

Sperm Whale (Physeter macrocephalus) 

The NOAA stock assessment report divides sperm whales within the U.S. Pacific EEZ into three discrete, 

noncontiguous areas: (1) waters around the Hawaiian Islands, (2) California, Oregon, and Washington 

waters, and (3) Alaskan waters (Carretta et al., 2005). The best available abundance estimate for the 

Hawaiian Islands stock of the sperm whale is 7,082 individuals (CV = 0.30) (Barlow, 2003; Carretta et 

al., 2005). Sperm whale abundance in the eastern temperate North Pacific Ocean is estimated to be 

32,100 individuals and 26,300 individuals by acoustic and visual detection methods, respectively (Barlow 

and Taylor, 2005). 

Sperm whales are widely distributed throughout the Hawaiian Islands year-round (Rice, 1960; 

Shallenberger, 1981; Lee, 1993; and Mobley, et al. 2000). Sperm whale clicks recorded from 

hydrophones off Oahu confirm the presence of sperm whales near the Hawaiian Islands throughout the 

year (Thompson and Friedl, 1982). The primary area of occurrence for the sperm whale is seaward of the 

shelf break in the Hawaiian Islands Hawaiian Islands Operating Area. There is a rare occurrence of 

sperm whales from the shore to the shelf break. This occurrence prediction is based on the possibility of 

this typically deepwater species being found in insular shelf waters that are in such close proximity to 

deep water. Occurrence patterns are assumed to be similar throughout the year. 



3.5.2.5.2 Endangered Pinniped 

Hawaiian Monk Seal (Monachus schauinslandi) 

Hawaiian monk seals are managed as a single stock although there are six main reproductive 

subpopulations at French Frigate Shoals, Laysan Island, Lisianski Island, Pearl and Hermes Reef, 

Midway Island, and Kure Atoll (Ragen and Lavigne, 1999; Carretta et al., 2005). Genetic comparisons 

between the Northwestern and Main Hawaiian Island seals have not yet been conducted, but observed 

interchange of individuals among the regions is extremely rare, suggesting that these may be more 

appropriately designated as separate stocks; further research is needed (Carretta et al., 2005). 

The best estimate of the total population size is 1,304 individuals (Carretta et al., 2005). There are an 

estimated 55 seals in the Main Hawaiian Islands (Baker and Johanos, 2004; U.S. Department of the Navy, 

Commander, U.S. Pacific Fleet, 2005; Carretta et al., 2005). The vast majority of the population is 

present in the Northwestern Hawaiian Islands. The trend in abundance for the population over the past 20 

years has mostly been negative (Baker and Johanos, 2004; Carretta et al., 2005). A self-sustaining 

subpopulation in the Main Hawaiian Islands may improve the monk seal’s long-term prospects for 

recovery (Marine Mammal Commission, 2003; Baker and Johanos, 2004; Carretta et al., 2005). 

Critical habitat for the Hawaiian monk seal is designated from the shore out to 37 m (20 fathoms) in 10 

areas of the Northwestern Hawaiian Islands (National Marine Fisheries Service, 1988). 

Most monk seal haulout events in the Main Hawaiian Islands have been on the western islands of Niihau 

and Kauai (Baker and Johanos, 2004; Carretta et al., 2005), although sightings or births have now been 

reported for all of the Main Hawaiian Islands, including Lehua and Kaula (Marine Mammal Commission, 

2003; Baker and Johanos, 2004). 

Hawaiian monk seals show very high site fidelity to natal islands, with only about 10% of individuals 

moving to another island in their lifetime (Gilmartin and Forcada, 2002). While monk seals do move 

between islands, long-distance movements are not common. Seals move distances of up to 250 km on a 

regular basis, but distances of more than 1,000 km have not been documented (DeLong et al., 1984; 

Ragen and Lavigne, 1999). 

Primary occurrence of monk seals is expected in a continuous band between Nihoa, Kaula, Niihau, and 

Kauai. This band extends from the shore to around the 500 m isobath and is based on the large number of 

sightings and births recorded in this area (Westlake and Gilmartin, 1990; Ragen and Finn, 1996; Marine 

Mammal Commission, 2003; Baker and Johanos, 2004). An area of secondary occurrence is expected 

from the 500 m isobath to the 1,000 m isobath around Nihoa, Kaula, Niihau, and Kauai. A continuous 

area of secondary occurrence is also expected from the shore to the 1,000 m isobath around the other 

Main Hawaiian Islands, taking into account sighting records, the location of deepsea corals, and the 

ability of monk seals to forage in water deeper than 500 m (Parrish et al., 2002; Severns and Fiene- 

Severns, 2002; Kona Blue Water Farms, 2003; Kubota, 2004; Anonymous, 2005; Fujimori, 2005; Parrish, 

personal communication, 2005). The Pearl Harbor entrance is included in the area of secondary 

occurrence based on sightings of this species near the entrance of the harbor (U.S. Department of the 

Navy, 2001b). There is a rare occurrence of the monk seal seaward of the 1,000 m isobath. Occurrence 

patterns are expected to be the same throughout the year. 

An underwater audiogram obtained for the Hawaiian monk seal showed relatively poor hearing 

sensitivity, as well as a narrow range of best sensitivity and a relatively low upper frequency limit 



(Thomas et al., 1990). The data demonstrated best underwater hearing at 12 kHz to 28 kHz and 60 kHz to 

70 kHz (Thomas et al., 1990). It should be noted that this audiogram is based on a single marine mammal 

whose hearing curve has some characteristics that suggest its responses may have been affected by 

disease or age (Reeves et al., 2001). 

3.5.2.5.3 Non-Endangered Cetaceans 

Minke Whale (Balaenoptera acutorostrata) 

For the NOAA stock assessment report, there are three stocks of minke whales within the U.S. Pacific 

EEZ: (1) a Hawaiian stock; (2) a California/Oregon/Washington stock; and (3) an Alaskan stock (Carretta 

et al., 2005). There currently is no abundance estimate for the Hawaiian stock of minke whales, which 

appears to occur seasonally (approximately November through March) around the Hawaiian Islands 

(Carretta et al., 2005). 

The minke whale is expected to occur seasonally in the Hawaiian Islands Operating Area (Barlow 2003). 

Abundance is expected to be higher between November and March (Carretta et al. 2005). Therefore, an 

area of secondary occurrence is seaward of the shoreline during the fall-winter period. Both visual and 

acoustic detections of minke whales have been reported for this area (e.g., Balcomb, 1987; Thompson and 

Friedl, 1982; Barlow, et al. 2004; Carretta et al., 2005; Norris et al., 2005). The occurrence pattern takes 

into account both sightings in shallow waters in some locales globally as well as the anticipated oceanic 

occurrence of this species (Jefferson, personal communication, 2005). “Boings” were recorded in waters 

with a bottom depth of approximately 1,280 m to 3,840 m (Norris et al., 2005). Norris et al. (2005) 

reported sighting a minke whale 93 km southwest of Kauai, in waters with a bottom depth of 

approximately 2,560 m. During the spring-summer period, there is a rare occurrence for the minke whale 

throughout the entire Hawaiian Islands Operating Area. 

Bryde’s Whale (Balaenoptera edenybrydei) 

For the NOAA stock assessment reports, Bryde’s whales within the U.S. Pacific EEZ are divided into two 

areas: (1) Hawaiian waters, and (2) the eastern tropical Pacific Ocean (east of 150°W and including the 

Gulf of California and waters off California) (Carretta et al., 2005). The abundance estimate for the 

Hawaiian Islands stock of the Bryde’s whale is 493 individuals (CV = 0.34) (Barlow, 2003). 

Bryde’s whales are seen year-round throughout tropical and subtropical waters (Kato, 2002) and are also 

expected in the Hawaiian Islands Operating Area year-round (Jefferson, personal communication, 2005). 

It should be noted that more sightings are reported for the Northwestern Hawaiian Islands than in the 

Main Hawaiian Islands (e.g., Barlow et al., 2004; Carretta et al., 2005). Bryde’s whales have been 

reported to occur in both deep and shallow waters globally. There is a secondary occurrence of Bryde’s 

whales seaward of the 50 m isobath in the Hawaiian Islands Operating Area. Bryde’s whales are 

sometimes seen very close to shore and even inside enclosed bays (see Best et al., 1984). 

Pygmy and Dwarf Sperm Whales (Kogia breviceps and Kogia sima, respectively) 

Pygmy and dwarf sperm whales within the U.S. Pacific EEZ are each divided into two discrete, noncontiguous 

areas: (1) Hawaiian waters, and (2) waters off California, Oregon, and Washington (Carretta 

et al., 2005). The best available estimate of abundance for the Hawaiian stock of the pygmy sperm whale 

is 7,251 individuals (CV = 0.77) (Barlow, 2003; Carretta et al., 2005). The best available estimate of 

abundance for the Hawaiian stock of the dwarf sperm whale is 19,172 individuals (CV = 0.66) (Barlow, 




Both species of Kogia generally occur in waters along the continental shelf break and over the continental 

slope (e.g., Baumgartner et al., 2001; McAlpine, 2002; Baird, 2005a). The primary occurrence for Kogia 

is seaward of the shelf break in the Hawaiian Islands Operating Area. This takes into account their 

preference for deep waters. There is a rare occurrence for Kogia inshore of the area of primary 

occurrence. Occurrence is expected to be the same throughout the year. 

Beaked Whales (Family Ziphiidae) 

Seven species of beaked whales are known to occur in the North Pacific Ocean (MacLeod et al., in press); 

only three are expected to occur in the Hawaiian Islands Operating Area: Cuvier’s beaked whale, 

Blainville’s beaked whale (Mesoplodon densirostris), and Longman’s beaked whale. Of these species, 

only the Cuvier’s beaked whale is relatively easy to identify. 

The best available estimate of abundance for the Hawaiian stock of the Cuvier’s beaked whale is 12,728 

individuals (CV = 0.83) (Barlow, 2003; Carretta, et al. 2005). The best available estimate of abundance 

for the Hawaiian stock of the Blainville’s beaked whale is 2,138 individuals (CV = 0.77) (Barlow, 2003; 

Carretta, et al. 2005). The best available estimate of abundance for the Hawaiian stock of the Longman’s 

beaked whale is 766 individuals (CV = 1.05) (Barlow, 2003; Carretta, et al. 2005). 

Cuvier’s beaked whales are generally sighted in waters with a bottom depth greater than 200 m and are 

frequently recorded at depths of 1,000 m or more (Gannier, 2000; MacLeod, et al. 2004). They are 

commonly sighted around seamounts, escarpments, and canyons. In the eastern tropical Pacific Ocean, 

the mean bottom depth for Cuvier’s beaked whales is approximately 3,400 m, with a maximum depth of 

over 5,100 m (Ferguson, 2005). Both Baird et al. (2004) and MacLeod et al., (2004) reported that 

Blainville’s beaked whales are found in shallower waters than Cuvier’s beaked whales in the Hawaiian 

Islands and the Bahamas, respectively. 

Most of the ecological information for the Blainville’s beaked whale comes from the northern Bahamas 

(MacLeod et al., 2004; MacLeod and Zuur, 2005). In the eastern tropical Pacific Ocean, the mean bottom 

depth for Blainville’s beaked whale sightings is just over 3,500 m and a maximum depth of 5,750 m 

(Ferguson, 2005). The Longman’s beaked whale appears to have a preference for warm tropical water, 

with most sightings occurring in waters with a sea surface temperature warmer than 26°C (Pitman et al., 

1999). 

Vocalizations of what are believed to be beaked whales are routinely detected in hydrophone recordings 

from the instrumented range at PMRF, where USWEX have occurred since 2005 and ASW operations 

have been ongoing since establishment of the underwater range in the 1980’s. In addition, recent research 

results from McSweeney et. al., (2007) indicate site fidelity for a number individual beaked whales in the 

Alenuehaha Channel (between Hawaii and Maui) where ASW exercises and USWEX have been 

occurring for years. The continual presence of beaked whales in these areas where active sonar use has 

been ongoing for years, provides an indication that in Hawaii (minimally), beaked whales and sonar use 

can coexist without apparent impact on the presence of beaked whales. 

Rough-Toothed Dolphin (Steno bredanensis) 

Nothing is known about stock structure for the rough-toothed dolphin in the North Pacific Ocean 

(Carretta et al., 2005). The best available estimate of abundance for the Hawaiian stock of the roughtoothed 

dolphin is 19,904 individuals (CV = 0.52) (Carretta et al., 2005). 



In the Main Hawaiian Islands, this species is found in waters with bottom depths ranging from 250 m to 

4,320 m, with sighting rates highest in the deepest portions (2,000 to 4,000 m) (Baird personal 

communication, 2005b). 

Rough-toothed dolphins are found in tropical to warm-temperate waters globally, rarely ranging north of 

40°N or south of 35° (Miyazaki and Perrin, 1994). In the Main Hawaiian Islands, this species appears to 

demonstrate site fidelity to specific islands (Baird, personal communication, 2005b). 

Primary occurrence for the rough-toothed dolphin is from the shelf break to seaward of the Hawaiian 

Islands Operating Area boundaries. There is also an area of rare occurrence of rough-toothed dolphins 

from the shore to the shelf break. 

Common Bottlenose Dolphin (Tursiops truncatus) 

The best available estimate of abundance for the Hawaiian stock of the bottlenose dolphin is 3,263 

individuals (CV = 0.60) (Barlow, 2003; Carretta, et al. 2005). 

Bottlenose dolphins found in nearshore waters around the Main Hawaiian Islands are island-associated, 

with all sightings occurring in relatively nearshore and shallow waters (


Spinner dolphins occur in both oceanic and coastal environments. Most sightings of this species have 

been associated with inshore waters, islands, or banks (Perrin and Gilpatrick, 1994). 

Spinner dolphins occur year-round throughout the Hawaiian Islands Operating Area, with primary 

occurrence from the shore to the 4,000 m isobath. This takes into account nearshore resting habitat and 

offshore feeding areas. Spinner dolphins are expected to occur in shallow water (50 m or less) resting 

areas throughout the middle of the day, moving into deep waters offshore during the night to feed. 

Primary resting areas are along the west side of Hawaii, including Makako Bay, Honokohau Bay, Kailua 

Bay, Kealakekua Bay, Honaunau Bay, Kauhako Bay, and off Kahena on the southeast side of the island 

(Östman-Lind et al., 2004). Along the Waianae coast of Oahu, spinner dolphins rest along Makua Beach, 

Kahe Point, and Pokai Bay during the day (Lammers, 2004). Kilauea Bay in Kauai is also a popular 

resting bay for Hawaiian spinner dolphins (Jefferson, personal communication, 2005). There is an area of 

secondary occurrence seaward of the 4,000 m isobath. Although sightings have been recorded around the 

mouth of Pearl Harbor (Lammers, 2004), spinner dolphin occurrence is expected to be rare. Occurrence 

patterns are assumed to be the same throughout the year. It is currently not known whether individuals 

move between islands or island groups (Carretta et al., 2005). 

Striped Dolphin (Stenella coeruleoalba) 

The best available estimate of abundance for the Hawaiian stock of the striped dolphin is 10,385 


The striped dolphin regularly occurs throughout the Hawaiian Islands Operating Area. There is a primary 

occurrence for the striped dolphin seaward of the 1,000 m isobath based on sighting records and the 

species’ known preference for deep waters. Striped dolphins are occasionally sighted closer to shore 

(Mobley et al., 2000); therefore, an area of secondary occurrence is expected from the 100 m to the 1,000 

m isobaths. Occurrence patterns are assumed to be the same throughout the year. 

Risso’s Dolphin (Grampus griseus) 

The best available estimate of abundance for the Hawaiian stock of the Risso’s dolphin is 2,351 


There is an area of secondary occurrence between the 100 m and 5,000 m isobaths based on the known 

habitat preferences of this species, as well as the paucity of sightings even though there is extensive aerial 

and boat-based survey coverage near the islands. There is a narrow band of rare occurrence from the 

shore to the 100 m isobath. Risso’s dolphins are expected to be rare seaward of the 5,000 m isobath. 

Occurrence patterns are assumed to be the same throughout the year. 

Melon-headed Whale (Peponocephala electra) 

The best available estimate of abundance for the Hawaiian stock of the melon-headed whale is 2,947 

individuals (Barlow, 2003; Carretta et al., 2005). 

Melon-headed whales are most often found in offshore, deep waters. Melon-headed whales in the Main 

Hawaiian Islands are found in waters with bottom depths ranging from 255 to 4,407 m, with a preference 

for waters with a bottom depth greater than 2,000 m (Baird, personal communication, 2005b; Baird et al., 

2003). Nearshore sightings are generally from areas where deep, oceanic waters are found near the coast 

(Perryman, 2002). 



Preliminary results from photo-identification work in the Main Hawaiian Islands suggest inter-island 

movements by some individuals (e.g., between the islands of Kauai and Hawaii) as well as some 

residency by other individuals (e.g., at the island of Hawaii) (Baird, personal communication, 2005b). 

The melon-headed whale is an oceanic species. Melon-headed whales are primarily expected to occur 

from the shelf break to seaward of the Hawaiian Islands Operating Area and vicinity. There is rare 

occurrence from the shore to the shelf break, which would take into account any sightings that could 

occur closer to shore since deep water is very close to shore at these islands. Occurrence patterns are 

assumed to be the same throughout the year. 

Fraser’s Dolphin (Lagenodelphis hosei) 

The best available estimate of abundance for the Hawaiian stock of the Fraser’s dolphin is 16,836 


Fraser’s dolphins have only recently been documented in Hawaiian waters (Carretta et al., 2005). 

Sightings have been recorded in the Northwestern Hawaiian Islands but not within the Main Hawaiian 

Islands (Barlow, 2003). There is a rare occurrence of the Fraser’s dolphin from the shore to seaward of 

the Hawaiian Islands Operating Area that takes into account that this is an oceanic species that can be 

found closer to the coast, particularly in locations where the shelf is narrow and deep waters are nearby. 


Pygmy Killer Whale (Feresa attenuata) 

The best available estimate of abundance for the Hawaiian stock of the pygmy killer whale is 817 


Pygmy killer whales regularly occur in the Hawaiian Islands Operating Area. Pygmy killer whales are 

easily confused with false killer whales and melon-headed whales, which are two species that also have 

expected occurrence in the Hawaiian Islands study area. The pygmy killer whale is primarily expected to 

occur from the shelf break to seaward of the Hawaiian Islands Operating Area boundaries. There is a rare 

occurrence from the shore to the shelf break that takes into account any sightings that could occur just 

inshore of the shelf break, since deep water is very close to shore here. Occurrence patterns are assumed 

to be the same throughout the year. Pygmy killer whales off the island of Hawaii demonstrate 

tremendous site fidelity to the island (Baird, personal communication, 2005b). 

False Killer Whale (Pseudorca crassidens) 

The best available estimate of abundance for the Hawaiian stock of the false killer whale is 268 

individuals (CV = 1.08) (Barlow, 2003; Carretta et al., 2005). This stock is listed as a strategic stock by 

NMFS because the estimated level of serious injury and mortality from the Hawaii-based tuna and 

swordfish longline fishery is greater than the potential biological removal (Carretta et al., 2005). 

False killer whales are commonly sighted in nearshore waters from small boats and aircraft, as well as 

offshore from longline fishing vessels (e.g., Mobley et al., 2000; Baird et al., 2003; Walsh and Kobayashi, 

2004). Baird et al. 2005 reported that false killer whales in the Hawaiian Islands occur in waters from 

about 40 m to 4,000 m. There is an area of primary occurrence for the false killer whale from the shore to 

the 2,000 m isobath. There is an additional area of primary occurrence seaward of the 4,000 m isobath on 

the south side of the islands, which takes into account false killer whale sighting and bycatch data in the 



southwestern portion of the Hawaiian Islands Operating Area (Forney, 2004; Walsh and Kobayashi, 

2004; Carretta et al., 2005). The area of secondary occurrence includes a narrow band between the 2,000 

m and 4,000 m isobaths south of the islands and the entire area north of the islands seaward of the 2,000 

m isobath. It has been suggested that false killer whales using coastal waters might be a discrete 

population from those in offshore waters and waters off the Northwestern Hawaiian Islands (Baird et al., 

2005; Carretta et al., 2005). The area of secondary occurrence takes into account the possibility of two 

different stocks, with a possible hiatus in their distribution (Jefferson, personal communication, 2005). 


Killer Whale (Orcinus orca) 

The best available estimate of abundance for the Hawaiian stock of the killer whale is 430 individuals 

(CV = 0.72) (Barlow, 2003; Carretta et al., 2005). 

Killer whales in general are uncommon in most tropical areas (Jefferson, personal communication, 2005). 

The distinctiveness of this species would lead it to be reported more than any other member of the dolphin 

family, if it occurs in a certain locale. Killer whales are infrequently sighted and found stranded around 

the Hawaiian Islands (Shallenberger, 1981; Tomich, 1986; Mobley et al., 2001b; Baird et al., 2003; Baird 

et al., in preparation), though with increasing numbers of boaters, sightings each year could be expected 

(Baird, personal communication, 2005b). Since the killer whale has a sporadic occurrence in tropical 

waters and can be found in both coastal areas and the open ocean, there is a rare occurrence of this species 

in the Hawaiian Islands Operating Area from the shoreline to seaward of the Hawaiian Islands Operating 

Area boundaries. Occurrence patterns are assumed to be the same throughout the year. 

Short-finned Pilot Whale (Globicephala macrorhynchus) 

The best available estimate of abundance for the Hawaiian stock of the short-finned pilot whale is 8,846 

individuals (CV = 0.49) (Barlow, 2003; Carretta et al., 2005). Stock structure of short-finned pilot whales 

has not been well-studied in the North Pacific Ocean, except in Japanese waters (Carretta et al., 2005). 

Pilot whales are sighted throughout the Hawaiian Islands (e.g., Shallenberger, 1981). 

Short-finned pilot whales are expected to occur year-round throughout the Hawaiian Islands Operating 

Area. They are commonly found in deep waters with steep bottom topography, including deepwater 

channels between the Main Hawaiian Islands, such as the Alenuihaha Channel between Maui and Hawaii 

(Balcomb, 1987). The area of primary occurrence for this species is between the 200 m and 4,000 m 

isobaths. Considering the narrow insular shelf and deep waters in close proximity to the shore, secondary 

occurrence is between the 50 m and 200 m isobaths. Another area of secondary occurrence extends from 

the 4,000 m isobath to seaward of the Hawaiian Islands Operating Area boundaries. Short-finned pilot 

whales are expected to be rare between the shore and the 50 m isobath. Occurrence patterns are assumed 

to be the same throughout the year. Photo-identification work suggests a high degree of site fidelity 

around the island of Hawaii (Shane and McSweeney, 1990). 

3.5.2.5.4 Non-Endangered Pinniped 

Northern Elephant Seal (Mirounga angustirostris) 

The population size has to be estimated since all age classes are not ashore at any one time of the year 

(Carretta et al., 2005). There is a conservative minimum population estimate of 60,547 elephant seals in 

the California stock (Carretta et al., 2005). Based on trends in pup counts, abundance in California is 



increasing by around 6% annually, but the Mexican stock is evidently decreasing slowly (Stewart et al., 


Northern elephant seals occur in Hawaiian waters only rarely as extralimital vagrants. The most farranging 

individual appeared on Nijima Island off the Pacific coast of Japan in 1989 (Kiyota et al., 1992). 

This demonstrates the great distances that these marine mammals are capable of covering. 

There is a rare occurrence of northern elephant seals throughout the Hawaiian Islands Operating Area 

year-round. The first confirmed sighting of a northern elephant seal in the Hawaiian Islands was a female 

found on Midway Island in 1978 that had been tagged earlier at San Miguel Island (off the coast of 

southern California) (Northwest and Alaska Fisheries Center, 1978). The first sighting of an elephant seal 

in the Main Hawaiian Islands occurred on the Kona coast of Hawaii in January 2002; a juvenile male was 

sighted hauled out at Kawaihae Beach and later at the Kona Village Resort (Fujimori, 2002; Antonelis, 

personal communication, 2004). Based on these sightings and documented long-distance movements as 

far west as Japan (Northwest and Alaska Fisheries Center, 1978; Antonelis and Fiscus, 1980; Tomich, 

1986; Kiyota, et al. 1992; Fujimori, 2002), rare encounters with northern elephant seals in the Hawaiian 

Islands Operating Area are possible. 

3.5.2.6 Threatened and Endangered Sea Turtles 

3.5.2.6.1 Green Turtle (Chelonia mydas) 

Although green turtle populations are in serious decline throughout much of the Pacific Ocean, their 

status is currently improving in Hawaiian waters, presumably due to effective protection at primary 

nesting areas in the Northwestern Hawaiian Islands and better enforcement of regulations prohibiting take 

of the species. However, the relatively recent increase in fibropapillomatosis, a tumor-producing disease 

in green turtles that is likely caused by a herpes-type virus, threatens to eliminate improvements in the 

status of the Hawaiian stock. There are no estimates of the current population size of green turtles in the 

Pacific Ocean (National Marine Fisheries Service and U.S. Fish and Wildlife Service, 1998a; 1998b). 

Green turtles occur in the coastal waters surrounding the Main Hawaiian Islands throughout the year and 

also migrate seasonally to the Northwestern Hawaiian Islands in order to reproduce. 

Adult green turtles that breed in the Northwestern Hawaiian Islands make regular reproductive migrations 

from their foraging grounds either around the Main Hawaiian Islands or around the westernmost atolls in 

the Northwestern Hawaiian Islands. This has been evidenced by frequent mark-recapture and satellitetracking 

studies on both adult male and female green turtles (Balazs, 1976; 1983; Balazs and Ellis, 2000; 

Balazs et al., 1994). Juvenile green turtles can also make long-range movements throughout the Hawaiian 

archipelago. From June 2002 to March 2003, a captive-reared green turtle released off northwestern 

Hawaii traveled over 4,800 km around the Hawaiian Islands, swimming as far west as the waters between 

Nihoa and Necker Islands before turning around and heading back to the Main Hawaiian Islands 

(Thompson, 2003). 

The largest nesting colony in the central Pacific Ocean occurs at French Frigate Shoals in the 

Northwestern Hawaiian Islands, where about 200 to 700 females nest each year. On occasion, green 

turtles also nest in the Main Hawaiian Islands. The most famous nesting green turtle in the Main 

Hawaiian Islands is turtle 5690, known by sea turtle biologists as “Maui Girl.” This turtle, which was 

raised to a year old at Oahu’s Sea Life Park and then tagged and released, has nested on beaches near 

Lahaina, Maui in 2000, 2002, and 2004 (Leone, 2004). Other sporadic nesting events in the Main 



Hawaiian Islands have occurred along the north shore of Molokai, the northwest shore of Lanai, and the 

south, northeast, and southwest shores of Kauai (U.S. Department of the Navy, 2001b, 2002; National 

Ocean Service, 2001). 

Green turtles outnumber all other species combined in the nearshore waters of the Hawaiian archipelago. 

The available sighting and stranding data for the Hawaiian Islands Operating Area clearly evidence this. 

The area of year-round primary occurrence for green turtles is located in waters inshore of the 100 m 

isobath around all of the Main Hawaiian Islands and Nihoa. It is in these areas where reefs, their 

preferred habitats for foraging and resting, are most abundant. The area of secondary occurrence 

encompasses an oceanic zone surrounding the Hawaiian Islands. This area is frequently inhabited by 

adults that are migrating to the Northwestern Hawaiian Islands to reproduce and by pelagic stage 

individuals that have yet to settle into coastal feeding grounds of the Main Hawaiian Islands. Further 

offshore of this seasonal use zone is the area of year-round rare occurrence, as green turtles are not likely 

to be found in portions of the Hawaiian Islands Operating Area that are extremely far from land. 

3.5.2.6.2 Hawksbill Turtle (Eretmochelys imbricata) 

A lack of regular quantitative surveys for hawksbill turtles in the Pacific Ocean and the discrete nature of 

this species’ nesting have made it extremely difficult for scientists to assess the distribution and 

population status of hawksbills in the region (National Marine Fisheries Service and U.S. Fish and 

Wildlife Service, 1998c; Seminoff et al., 2003). Around the Hawaiian Islands, hawksbills are only known 

to occur in the coastal waters of the eight main and inhabited islands of the archipelago. Hawksbills 

forage throughout the Main Hawaiian Islands, although in much fewer numbers than green turtles. 

Hawksbills have been captured at several locations including Kiholo Bay and Kau (Hawaii), Palaau 

(Molokai), and Makaha (Oahu) (Hawaii Department of Land and Natural Resources, 2002). Strandings 

have been reported in Kaneohe and Kahana Bays (Oahu) as well as in other locations throughout the 

Main Hawaiian Islands (Eckert, 1993; National Marine Fisheries Service and U.S. Fish and Wildlife 

Service, 1998c). No reliable reports are known from Niihau (U.S. Department of the Navy, 2001b). 

Hawksbills are much more abundant in the shallow, nearshore waters of the Hawaiian Islands than they 

are in deeper, offshore waters of the central Pacific Ocean. 

Throughout the year, the area of primary occurrence for hawksbill turtles can be found in Hawaiian 

Islands Operating Area waters shoreward of the 100 m isobath. Beyond the 100 m isobath, hawksbill 

occurrence is rare year round. Pelagic stage individuals may occur in oceanic waters off the Main 

Hawaiian Islands and Nihoa, but these life stages are nearly impossible to sight during surveys and rarely, 

if ever, interact with the pelagic longline fishery. Of the five sea turtle species known to occur in the 

Hawaiian Islands Operating Area, the hawksbill is the only one that is not taken by Hawaiian longliners 

(Kobayashi and Polovina, 2005). 

3.5.2.6.3 Olive Ridley Turtle (Lepidochelys olivacea) 

Until the advent of commercial exploitation, the olive ridley was highly abundant in the eastern tropical 

Pacific Ocean probably outnumbering all other sea turtle species combined in the area (National Marine 

Fisheries Service and U.S. Fish and Wildlife Service, 1998e). Clifton et al. (1995) estimated that a 

minimum of 10 million olive ridleys were present in ocean waters off the Pacific coast of Mexico prior to 

1950. Even though there are no current estimates of worldwide abundance, the olive ridley is still 

considered the most abundant of the world’s sea turtles. However, the number of olive ridley turtles 



occurring in U.S. territorial waters is believed to be small (National Marine Fisheries Service and U.S. 

Fish and Wildlife Service, 1998e). 

Olive ridleys are rare visitors to the nearshore waters around the Hawaiian Islands, although they have 

been recorded in increasing numbers over the past two decades. Juveniles and adults have become 

entangled in fishing gear and other marine debris in nearshore waters off Hawaii, Molokai, Maui, and 

Oahu (Eckert, 1993). A total of 26 olive ridley turtles have stranded in the Hawaiian Islands since 1982, 

making it the third most common species to strand after greens and hawksbills (Hawaii Department of 

Land and Natural Resources, 2002). Available information suggests that olive ridleys traverse through 

the oceanic waters surrounding the Hawaiian Islands during foraging and developmental migrations (Nitta 

and Henderson, 1993). 

In the Hawaiian Islands, a single nesting was recorded along Paia Bay, Maui in September 1985; 

however, there was no successful hatching associated with this event (Balazs and Hau 1986; National 

Ocean Service, 2001). Since there are no other known nesting records for the central Pacific Ocean, the 

above nesting attempt should be considered an anomaly (National Marine Fisheries Service and U.S. Fish 

and Wildlife Service, 1998e). 

About two-thirds of all olive ridleys found in the vicinity of the Hawaiian Islands are derived from eastern 

Pacific nesting populations, while the remaining one-third originate in the western Pacific Ocean or 

Indian Ocean. As a result, the Hawaiian Islands represent a point of convergence for these source areas 

(Hawaii Department of Land and Natural Resources, 2002). 

Based on the oceanic habitat preferences of this species throughout the Pacific Ocean, it has been 

determined that the area of year-round primary occurrence in the Hawaiian Islands Operating Area lies in 

waters beyond the 100 m isobath. Olive ridleys are frequently captured by pelagic longline fishermen in 

deep, offshore waters of the Hawaiian Islands Operating Area, especially during spring and summer. 

Inside of the 100 m isobath, olive ridley occurrence in the Hawaiian Islands Operating Area is rare year 

round. Like the loggerhead turtle, there have been few recorded sightings and strandings of this species 

in the nearshore waters of the Main Hawaiian Islands and Nihoa (as compared to the green and hawksbill 

turtles, which are primarily nearshore species). A significant number of strandings in an area likely 

indicates a strong presence in waters nearby, which is not the case here. A single recorded nesting 

attempt for the olive ridley over the past 20 years also indicates the lack of a need for this species to enter 

coastal waters surrounding the Hawaiian Islands. 

3.5.2.6.4 Leatherback Turtle (Dermochelys coriacea) 

There are few quantitative data available concerning the seasonality, abundance, or distribution of 

leatherbacks in the central North Pacific Ocean. The leatherback is not typically associated with insular 

habitats, such as those characterized by coral reefs, yet individuals are occasionally encountered in deep 

ocean waters near prominent archipelagos such as the Hawaiian Islands (Eckert, 1993). Leatherbacks are 

regularly sighted by fishermen in offshore waters surrounding the Hawaiian Islands, generally beyond the 

183 m contour, and especially at the southeastern end of the island chain and off the north coast of Oahu 

(Nitta and Henderson, 1993; Balazs, 1995; 1998). Leatherbacks encountered in these waters, including 

those caught incidental to fishing operations, may represent individuals in transit from one part of the 

Pacific Ocean to another (National Marine Fisheries Service and U.S. Fish and Wildlife Service, 1998f). 

Leatherbacks apparently have a wide geographic distribution throughout the region where the Hawaiian 

longline fishery operates, with sightings and reported interactions commonly occurring around seamount 



habitats located above the Northwestern Hawaiian Islands (from 35° to 45°N and 175° to 180°W) 

(Skillman and Balazs, 1992; Skillman and Kleiber, 1998). McCracken (2000) has also documented 

incidental captures of leatherbacks at several offshore locations around the Main Hawaiian Islands. 

Although leatherback bycatch events are common occurrences off the archipelago, leatherback stranding 

events on its beaches are not. Since 1982, only five leatherbacks have stranded in the Hawaiian Islands 

(National Marine Fisheries Service, Pacific Islands Fisheries Science Center, 2004). 

Satellite-tracking studies, a lack of Hawaiian stranding records, and occasional incidental captures of the 

species in the Hawaii-based longline fishery indicate that deep, oceanic waters are the most preferred 

habitats of leatherback turtles in the central Pacific Ocean. As a result, the area of year-round primary 

occurrence for the leatherback turtle encompasses all Hawaiian Islands Operating Area waters beyond the 

100 m isobath. Inshore of the 100 m isobath is the area of rare leatherback occurrence. This area is also 

the same year round. Leatherbacks were not sighted during any of the aerial surveys for which data were 

collected, all of which took place over waters lying in close proximity to the Hawaiian shoreline. 

Leatherbacks were not sighted during any of the NMFS shipboard surveys either, although their deep 

diving capabilities and long submergence times lessen the probability that observers will be able to spot 

them during marine surveys. 

3.5.2.6.5 Loggerhead Turtle (Caretta caretta) 

The NMFS and U.S. Fish and Wildlife Service (1998d) listed four records of this species for the 

Hawaiian Islands: two from the southeastern end of the archipelago, one from Kure Atoll (recovered from 

the stomach of a tiger shark), and a fourth from the coast of Oahu (seen just offshore of the Sheraton 

Waikiki hotel). All four individuals were identified as juvenile loggerheads and most likely drifted or 

traveled to the region from either Mexico or Japan. A single male loggerhead turtle has also been 

reported to visit Lehua Channel and Keamano Bay (located off the north coast of Niihau) every June 

through July (U.S. Department of the Navy, 2001b; National Ocean Service, 2001). Only one loggerhead 

stranding has been recorded in the Hawaiian Islands since researchers began documenting them in 1982. 

This event, which was recorded along the shores of Kaneohe Bay, Oahu, was determined to be the result 

of a shark attack (National Marine Fisheries Service, Pacific Islands Fisheries Science Center, 2004). 

Genetic analyses indicate that nearly all of the loggerheads found in the North Pacific Ocean are born on 

nesting beaches in Japan (Bowen et al. 1995; Resendiz et al. 1998). Pacific loggerheads appear to utilize 

the entire North Pacific Ocean during the course of development, much like Atlantic loggerheads use the 

North Atlantic Ocean. There is substantial evidence that both stocks make two separate transoceanic 

crossings. The first crossing (west to east) is made immediately after hatching from the nesting beach, 

while the second (east to west) is made upon reaching either the late juvenile or adult life stage. 

The area of primary occurrence for the loggerhead turtle spans all ocean waters off the Main Hawaiian 

Islands and Nihoa beyond the 100 m isobath. This area, like the area of rare occurrence, which can be 

found between the Hawaiian Islands shoreline and the 100 m isobath, is the same throughout the year. 

Occurrence in nearshore waters is believed to be rare due to a lack of sighting and stranding records in 

those waters. Except for the four sighting and one stranding records listed previously, loggerheads have 

not been recorded at all on the Hawaiian shelf. 



3.5.3 Safety and Health—Ocean Area, Hawaiian Islands 

Training exercises within the Hawaiian Islands Operating Area are conducted in accordance with 

FACSFAC Pearl Harbor Instruction 3120.1D. PMRF and FACSFAC Pearl Harbor maintain surveillance 

and coordinate scheduling of the Hawaiian Islands Operating Areas to ensure maximum utilization, 

coordination, and safety. PMRF is the using agency for Warning Areas W-186, and W-188 and 

Restricted Airspace R-3101, and FACSFAC Pearl Harbor is the using agency for Warning Areas W-187, 

W-189, W-190, W-191, W-192, W-193, W-194, and W-196 and Restricted Area R-3107. The 

easternmost section of Warning Area W-188 (Rainbow) has been sub-delegated from PMRF to 

FACSFAC Pearl Harbor. Scheduling responsibilities for the air and surface space has been divided 

between PMRF and FACSFAC Pearl Harbor as listed above for the using agency. 

In addition, all submarine activities are scheduled by Commander, Submarine Force Pacific and 

coordinated through FACSFAC Pearl Harbor. For special operations, multi-participant, or hazardous 

weekend firings, PMRF and FACSFAC Pearl Harbor publish dedicated warning NOTAMs and 

NOTMARs. 

Operating Procedure 3120, FACSFAC Pearl Harbor, includes a description of each operating area within 

the Hawaiian Fleet Operating Area. The description includes the location, description, type of exercises, 

authorized ordnance, altitude, periods of usage, scheduling authority, communications frequencies, and 

special instructions including protected species considerations and restrictions. All activities must be in 

compliance with DoD Directive 4540.1 and OPNAVINST 3770.4A, which specify procedures for 

conducting aircraft operations and for missile/projectile firing (Pacific Missile Range Facility, Barking 

Sands, 1998). 


4.0 Environmental Consequences 

4.0 ENVIRONMENTAL CONSEQUENCES 

This chapter describes the potential environmental consequences of the Proposed Action described in 

Sections 2.4.1 and 2.4.2 being implemented through Alternatives 1, 2, and the No-Action Alternative. 

The non-ASW proposed actions described in Section 2.4.2 are the same for all three alternatives and will 

be described in detail under Section 4.1 Alternative 1. The analysis in this chapter compares the activities 

for each alternative with the potentially affected environmental components. 

Sections 4.1 through 4.3 discuss Alternatives 1, 2, and the No-Action Alternative respectively. Sections 

4.4 through 4.13 provide discussions of the following with regard to proposed USWEX activities: 

cumulative impacts; mitigation measures; adverse environmental effects that cannot be avoided; 

consistency with federal, state, and local land-use plans, policies, and controls; energy requirements and 

conservation potential; irreversible or irretrievable commitment of resources; relationship between shortterm 

uses of the human environment and the maintenance and enhancement of long-term productivity; 

and natural or depletable resource requirements and conservation potential. 

To assess the potential for and significance of environmental impacts from the ongoing exercises 

proposed for USWEX, a list of activities necessary to accomplish the Proposed Action was first 

developed (Chapter 2.0). Next, the environmental setting was described, with emphasis on any special 

environmental sensitivities (Chapter 3.0). The Proposed Action was then compared with the potentially 

affected environmental components to determine the environmental impacts. Proposed USWEX 

activities were also reviewed against existing environmental documentation on current and planned 

actions and information on anticipated future projects at each of the sites to determine the potential for 

cumulative impacts. 

4.1 ALTERNATIVE 1—CONDUCT SIX USWEX PER YEAR 

Alternative 1 is a proposal designed to meet the maximum U.S. Navy and DoD current and near-term 

operational training requirements based on known and expected force structure. This Alternative analyzes 

four CSG USWEXs and two ESG USWEXs per year occurring in Hawaii. Although the USWEX is 

dependent on the U.S. Navy’s operational schedules, this Alternative assumes that half of the CSG 

USWEXs (two) would occur between November and April, and half of the CSG USWEXs would occur 

between May and October. The same ratio is also assumed to apply to the ESG USWEXs. The CSGs 

generally conduct their USWEXs south of Oahu in order to take advantage of the geography and also to 

allow its embarked air wing to conduct training at PTA on the island of Hawaii. The ESGs generally 

conduct their USWEXs north and west of Oahu in order to have the option of conducting AMPHIBEX 

operations at PMRF on Kauai, or at MCTAB on Oahu. In addition to AMPHIBEX, USWEX events 

would include ASWEX, GUNEX, ACM, ASMEX, and STWEX exercises that would occur as described 

in Section 2.2.2. 

4.1.1 Pacific Missile Range Facility (PMRF), Kauai 

USWEX activities conducted at PMRF include the AMPHIBEX as described in Chapter 2.0. The region 

of influence for USWEX activities is shown in Figure 3-1. AMPHIBEX would be conducted in the 

Majors Bay area as well as adjacent beach and inland areas. 



4.1.1.1 Airspace—PMRF—AMPHIBEX 

Air activity is coordinated by PMRF Range Control. For operations including 10 or more aircraft, the 

PMRF manager submits a NOTAM to the affected Flight Service Station and includes this information to 

the airfield Air Traffic Information Service (U.S. Army Garrison, Hawaii, 1996). 

Amphibious landings entail no use of controlled airspace other than localized use of rotary wing craft and 

jet aircraft in support of amphibious landing exercises within predefined areas. No impact to airspace has 

been identified at PMRF from previous AMPHIBEXs. The ongoing PMRF exercises, including USWEX 

activities, would continue to utilize the existing airspace and follow Federal Aviation Administration 

flight rules. No new special use airspace proposal or any modification to the existing special use airspace 

is contemplated to accommodate activities. Under Alternative 1, the existing airspace would be used for 

approximately 12 days per year. With proper scheduling and adherence to Federal Aviation 

Administration flight rules, no impacts to the airspace at PMRF would result from USWEX activities. 

4.1.1.2 Biological Resources—PMRF—AMPHIBEX 

USWEX at PMRF could affect terrestrial biological resources directly or indirectly. Movement of 

personnel, vehicles, and equipment across the beach and into upland areas could crush, trample, or uproot 

vegetation, or compact surface soils. In the absence of avoidance procedures, the exercises could disrupt 

the foraging, resting, or nesting activities of wildlife, such as the Hawaiian monk seal (Monachus 

schauinslandi) or green sea turtle (Chelonia mydas). Noise, especially from landing craft and helicopters, 

likely would startle birds and other wildlife in the vicinity. Unshielded lighting for night operations could 

disorient nocturnal wildlife, such as the Hawaiian hoary bat (Lasiurus cinereus semotus) or Newell's 

shearwater (Puffinus auricularis newelli). 

Potential impacts of past amphibious landings have been monitored. Observations indicate that, due to 

the procedures in place at PMRF as described below, and the continuing public use of the Majors Bay 

beach area, the impact from USWEX activities would be insignificant. Within 1 hour prior to initiation of 

the AMPHIBEX landing activities, landing routes and beach areas would be surveyed for the presence of 

sensitive wildlife. If any marine mammals or sea turtles were found to be present on the beach, the 

exercise would be delayed until the animals left the area. Therefore, potential AMPHIBEX activities at 

PMRF would result in no effect to Hawaiian monk seals or green sea turtles. In accordance with the 

mitigation measures adopted for the PMRF Enhanced Capability EIS (Pacific Missile Range Facility, 

Barking Sands, 1998), night lighting would be shielded to the extent practical to minimize its potential 

effect on night-flying birds in the beach area. With the implementation of these measures, impacts on 

wildlife in the vicinity of Majors Beach from the USWEX activities under Alternative 1 would be 

insignificant. Therefore, AMPHIBEX activities would result in no effect to the Hawaiian hoary bat or 

Newell’s shearwater. 

Impacts of the USWEX activities on vegetation would be insignificant because no unique, rare, or 

otherwise sensitive plants or plant communities exist in the area of potential disturbance as noted 

previously in Section 3.1.2. 

Potential impacts on marine mammals within PMRF's ocean ranges are addressed in Section 4.1.5. 



4.1.1.3 Cultural Resources—PMRF—AMPHIBEX 

No cultural resources sites have been recorded for Majors Bay or its associated beach landing and staging 

areas (Pacific Missile Range Facility, Barking Sands, 1998). USWEX activities at PMRF do not involve 

excavation or substantial disruption of surface soils, so inadvertent discovery of cultural deposits is highly 

unlikely. Potential impacts from amphibious landings thus are not anticipated. A cultural resources site 

lies adjacent to the upland area proposed for the overnight stay of USWEX participants, but this site is 

well-marked as an exclusion zone. This area would not be disturbed by the overnight activities. Thus, 

impacts on cultural resources at PMRF from the USWEX activities would be insignificant. 

Implementing an appropriate exercise monitoring program, consulting with the Hawaii State Historic 

Preservation Office, and following PMRF’s Integrated Cultural Resources Management Plan will 

provide additional confidence that USWEX would have no adverse effects on cultural resources at 

PMRF. 

4.1.1.4 Safety and Health—PMRF—AMPHIBEX 

Standard operating procedures including the use of clearance zones to protect personnel would be 

followed for the AMPHIBEX activities; thus, adverse impacts on safety and health are not anticipated. 

4.1.2 Marine Corps Training Area Bellows (MCTAB), Oahu 

4.1.2.1 Airspace—MCTAB—AMPHIBEX 

USWEX activities entail no use of controlled airspace other than localized use of rotary wing craft within 

predefined areas. No impact to airspace has been identified. 

4.1.2.2 Biological Resources—MCTAB—AMPHIBEX 

During training exercises, ground activities could temporarily impact biota on or near the shore and in the 

littoral environment. Potential environmental impacts on terrestrial and marine biota include effects from 

activities such as troop, personnel, and equipment movements and amphibious vehicles, including 

Landing Craft, Utility and AAVs. Amphibious landings have taken place for many years at MCTAB, and 

the impacts on beach landing sites have been assessed in previous U.S. Navy documents (U.S. Pacific 

Command, 1995; Marine Corps Base–Hawaii, 2001). According to previous research, soldiers training 

on foot are not expected to adversely affect vegetation or wildlife in the beach landing areas. Damage to 

vegetation from tracked vehicles is not likely if the vehicles are restricted to existing tank trails and do not 

travel off-road (U.S. Pacific Command, 1995). Restricting vehicles to existing ramps, trails, and 

roadways thus would minimize this effect. 

Threatened and endangered bird species have been observed in wetlands along Waimanalo Stream north 

of the amphibious landing beach. Noise and movement of vehicles, helicopters, and landing craft may 

temporarily displace sensitive bird species from feeding, resting, and nesting areas. Training activities are 

short in duration, however, and are not expected to affect the areas where the birds are most likely to nest. 

Training within the range areas regularly used for AMPHIBEX would not substantially increase the threat 

to these species (U.S. Pacific Command, 1995). Therefore, AMPHIBEX activities would result in no 

effect to threatened and endangered bird species at MCTAB. 



Areas of principal concern for near-shore areas are the disturbance of live coral on the ocean floor and 

disturbance to threatened and endangered marine life, including the Hawksbill turtle, green sea turtles, 

humpback whales, and Hawaiian monk seal. 

Impacts to the live coral coverage from tracked vehicles have not been found to be significant in previous 

studies, and are minimized by use of regular transit routes through sandy bottom areas. Crews are welltrained 

and follow established procedures, such as having a designated lookout watching for other vessels, 

obstructions to navigation, marine mammals (whales or monk seals), or sea turtles (U.S. Pacific 

Command, 1995). The landing routes and beach areas would be determined to be clear of marine 

mammals and sea turtles within 1 hour of the landing activities. If any are seen as noted as standard 

operating procedure, the exercise would be delayed until the animals leave the area. The operation of 

amphibious vehicles would therefore result in no effect to endangered or threatened species, such as 

humpback whales, monk seals or green sea turtles. 

No impacts on marine biota or threatened or endangered species from USWEX activities are expected, 

and no mitigation measures are required. Instructions to the DoD elements engaged in amphibious 

exercises designed to further minimize potential impacts would include: 

• Conduct surveys prior to use of amphibious launch vehicles to ensure that humpback whales are 

not disturbed. 

• Establish buffer zones in locations where green turtles are known to feed so that amphibious 

exercises do not disturb these areas. 

• Mark and monitor green turtle nests discovered on beaches so they are not affected by training 

activities. 

(U.S. Pacific Command, 1995) 

In summary, no significant impacts on terrestrial species from AMPHIBEX activities are expected under 

Alternative 1. 

4.1.2.3 Cultural Resources—MCTAB—AMPHIBEX 

The potential effects of USWEX activities on currently unknown cultural resources include disruption of 

fragile structures or sub-surface artifacts and human remains by foot and vehicle traffic. However, since 

the beach and adjacent areas to be utilized by USWEX activities are also heavily utilized by the public for 

recreation, the additional temporary traffic would have minimal impact to cultural resources. 

An archaeological survey at Bellows Air Force Station identified 18 historic and archaeological sites, 

including human burials (U.S. Pacific Command, 1995). None of these sites are located in the beach 

landing area, but several bracket the area. The two closest sites (4852 and 4851) have site features of 

habitation, workshop, and burials. Site 4852 includes the 018 Bellows Dune Site, which is on the 

National Register of Historic Places, and may be one of the earliest Hawaiian occupations on the Islands. 

Both areas are identified as off-limits on training overlays to ensure that there is no disturbance caused by 

training. Site 4851 is within an adjacent maneuver training area. Site 4852 is north of Waimanalo Stream 

and outside training areas. (U.S. Pacific Command, 1995) Thus, impacts to cultural resources are not 

anticipated. 



USWEX activities would adhere to the cultural resources mitigation measures identified in the 1995 EIS 

for the land use and development plan, and in subsequent planning documents (e.g., Integrated Cultural 

Resources Management Plan). Substantial additional impacts on unknown cultural resources from 

USWEX activities thus are not expected. Overall, USWEX activities at MCTAB under Alternative 1 

would have no significant impact on cultural resources. 

4.1.2.4 Land Use—MCTAB—AMPHIBEX 

Use of the beach and adjacent areas at MCTAB by USWEX activities would not change or alter on-base 

or off-base land use patterns. However, since the beach area is open to the public from noon on Fridays 

until 8:00 a.m. on Monday, any USWEX activities during a weekend would require closure of the beach 

to public access. These closures would be kept to the minimum time needed to conduct the exercises and 

ensure the public is properly protected. Standard modification procedures would be followed. Overall, 

the impacts to land use are considered to be temporary and insignificant. 

4.1.2.5 Noise—MCTAB—AMPHIBEX 

Ambient noise sources may include wind, surf, highway traffic, aircraft operations, and other local noisegenerating 

land uses. Noise sources from the exercise may include helicopter operations, fixed-wing 

aircraft, and operation of diesel engines of landing craft and tracked vehicles. During an AMPHIBEX, 

the total perceived noise level would be a combination of ambient background noise and noise from the 

training exercises. 

Noise levels at MCTAB have been studied during previous AMPHIBEXs to determine the likely 

propagation of noise under realistic conditions (U.S. Pacific Command, 1995). Noise from those 

previous exercises, involving AAVs, did not exceed noise impact thresholds in any off-base areas. The 

Advanced AAV, which will be used for future AMPHIBEXs, generates about 1–3 decibels more on land 

than the AAV (U.S. Department of the Navy, 2003). Therefore, off-site noise levels during future 

AMPHIBEX activities can be expected to be slightly higher than during past AMPHIBEXs. Such a 

marginal, short-term increase in ambient noise levels on a few days out of the year would not constitute a 

significant noise impact. 

4.1.3 Kaula 

4.1.3.1 Airspace—Kaula—STWEX, GUNEX 

The ongoing, continuing exercises, including USWEX activities, would continue to utilize the existing 

airspace (R-3107 and W-187). No new special use airspace proposal or any modification to the existing 

special use airspace is contemplated to accommodate the Proposed Action. USWEX would coordinate 

with the Honolulu Combined Center Radar Approach Control (on behalf of FACSFAC Pearl Harbor) for 

use of the Kaula-related restricted airspace for approximately 4 days, up to six times per year. Preexercise 

and ongoing coordination for use of the airspace would result in no impacts to the airspace over 

Kaula from USWEX activities. 

4.1.3.2 Biological Resources—Kaula—STWEX, GUNEX 

Thousands of seabirds of 13 different species nest on Kaula, including 4 species of concern (Black-footed 

albatross [Diomedea nigripes], Laysan albatross [Diomedea immutabilis], Christmas Island shearwater 

[Puffinus nativitatis], and blue-gray noddy [Procelsterna cerulea]). The number of birds on the island 



varies from month to month because of different breeding seasons among the species. However, one 

survey found over 90,000 birds nesting on the island (U.S. Department of the Navy, 2001b). About 8 

percent of the island is used for ordnance deliveries by the U.S. Navy. Assuming that the nesting habitat 

on the island is reasonably uniform and that the nests are evenly distributed, over 7,000 birds could 

attempt to nest within the impact area during peak nesting periods. The impact area is about 10 acres, so 

the average density during peak periods is about 700 nests per acre. 

USWEX activities would consist of delivering practice bombs to target areas on Kaula, and firing nonexplosive 

projectiles at fixed targets. From November to May, 20-mm and 30-mm cannon fire is 

prohibited (Pacific Missile Range Facility, Barking Sands, 1998). Impacting and ricocheting projectiles 

likely would startle nesting birds, and could result in the loss of a few individuals. Spotting charges from 

practice bombs would likely startle birds nesting near the targets. Birds frightened off their nests may 

abandon the nest and not breed again that season. Nest abandonment is highly species dependent. If the 

nest is abandoned, the bird may re-nest during the breeding season or not, depending in large part on the 

species and the point in the breeding season at which the nest is abandoned. USWEX activities would 

occur only six times per year at most, for a maximum of 4 days per exercise. Because USWEX would 

affect less than 10 percent of the island over less than 10 percent of the year, its effects on nesting 

seabirds under Alternative 1 would not be considered significant. 

Monk seals are reported to haul out on Kaula. USWEX activities likely would cause monk seals near the 

southern tip of the island to discontinue resting and return to the ocean. The seals likely would haul out 

again once the disturbance from the USWEX activities had ended. USWEX thus would have only an 

occasional, short-term effect on one element of the seal's habitat. This would not be considered a 

significant impact. Based on the limited potential impacts from USWEX activities, and past consultation 

regarding STWEX and GUNEX activities at Kaula, the U.S. Navy has determined the USWEX activities 

would result in no effect to monk seals. 

Ongoing STWEX and GUNEX activities at the southernmost 10 acres of Kaula involve some inadvertent 

ordnance release in the nearshore areas. As the humpback whales have been known to frequent this area 

during the winter season, use of live ordnance is restricted between the months of December and April. 

Sonobuoys are sometimes used to detect the presence of whales near Kaula. Prior to each gunnery run, a 

dry run is made over Kaula to verify the area is clear. (Pacific Missile Range Facility, Barking Sands, 

1998) 

Potential impacts to marine mammals in the Kaula vicinity are included in Section 4.1.5. 

4.1.3.3 Cultural Resources—Kaula—STWEX, GUNEX 

Six archaeological sites were observed outside of the impact area in 1999. STWEX and GUNEX 

exercises on Kaula are confined to the Impact Area. Most of the Impact Area has not been surveyed for 

cultural resources, due to the risks posed by unexploded ordnance. The Impact Area has been used 

extensively over a long period for ordnance deliveries and gunnery, however, so it likely does not contain 

above-ground or surface cultural resources that are sufficiently intact and that retain sufficient context to 

be eligible for listing on the National Register of Historic Places. In any case, the effects of the USWEX 

activities on cultural resources within the Impact Area would be minor and incremental in the context of 

the overall quantity of ordnance deliveries to this area from various military training activities. Therefore, 

the Proposed Action would have no significant effect on cultural resources on Kaula. 



4.1.3.4 Safety and Health—Kaula—STWEX, GUNEX 

To minimize health and safety risks, the U.S. Navy has established a Surface Danger Zone around Kaula 

and has closed the island and surrounding tidal zone to unauthorized personnel. In addition, Restricted 

Area R-3107 is located above Kaula as shown on Figure 3-2. Warning Area W-187 extends the safety 

zone beyond R-3107. With both surface and airspace safety zones, no adverse impacts from USWEX 

exercises are anticipated. 

4.1.4 Pohakuloa Training Area (PTA), Hawaii 

4.1.4.1 Airspace—PTA—STWEX 

STWEX and Close Air Support Exercise training and Live Fire Exercise occur routinely at PTA and are 

confined to the special use airspace R-3103 associated with Bradshaw Army Airfield and the range 

associated with PTA. Air activity is controlled and coordinated by PTA Range Control. For operations 

including 10 or more aircraft, the Bradshaw Army Airfield manager submits a NOTAM to Honolulu 

Flight Service Station to be published as a Honolulu Local NOTAM and as a Class D NOTAM. The 

Bradshaw Army Airfield manager provides this information to the airfield Air Traffic Information 

Service (U.S. Army Garrison, Hawaii, 1996). 

Implementing the proper coordination for use of the PTA-related restricted airspace for approximately 4 

days, up to six times per year would result in no impacts to the Pohakuloa airspace from USWEX 

activities. 

4.1.4.2 Biological Resources—PTA—STWEX 

STWEX at PTA is confined to the Impact Area (Figure 3-5). The Impact Area has not been surveyed for 

biological resources due to the risks posed by unexploded ordnance. In the absence of adverse 

modifications of the habitat, the Impact Area could be assumed to support an assemblage of native flora 

and fauna similar to that found in nearby areas of PTA. Impacts from ordnance deliveries and from other 

munitions landing within the Impact Area over a long period of use, however, likely have degraded the 

habitat, both through physical removal of native biota and by creating disturbed conditions in which 

aggressive non-native species can establish themselves. In addition, numerous ordnance-related fires over 

the years have tended to favor non-native invasive species over native Hawaiian species, which generally 

are not fire-adapted and recover slowly after a fire. 

The effects of the USWEX activities on biological resources within the Impact Area would be minor and 

incremental in the context of the overall quantity of ordnance deliveries to this area from various military 

training activities (U.S. Department of the Navy, Commander, U.S. Pacific Fleet, 2005). The impacts of 

USWEX exercises on biological resources at PTA under Alternative 1 are not likely to be significant. 

An Integrated Natural Resource Management Plan for PTA (U.S. Army Garrison, Hawaii and U.S. Army 

Corps of Engineers, 1998a) has been prepared to address protection and management of resources. 

Compliance with relevant Integrated Natural Resource Management Plan policies and procedures during 

USWEX exercises would further reduce the effects of training activities on biological resources. 

USWEX activities would therefore result in no effect to threatened and endangered species at PTA. 



4.1.4.3 Cultural Resources—PTA—STWEX 

STWEX exercises at PTA are confined to the Impact Area (Figure 3-5). The Impact Area has not been 

surveyed for cultural resources due to the risks posed by unexploded ordnance. The Impact Area has 

been used extensively over a long period for ordnance deliveries, however, so it likely does not contain 

above-ground or surface cultural resources that are sufficiently intact and that retain sufficient context to 

be eligible for listing on the National Register of Historic Places. The effects of the USWEX activities on 

cultural resources within the Impact Area would be minor and incremental in the context of the overall 

quantity of ordnance deliveries to this area from various military training activities. Therefore, the 

Proposed Action would have no significant effect on cultural resources at PTA. 

4.1.4.4 Noise—PTA—STWEX 

The STWEX activities associated with each USWEX could consist of up to 28 aircraft delivering a 

variety of ordnance within the Impact Area (see Chapter 2.0). USWEXs could occur up to six times per 

year, air wings could make more than one sortie per USWEX, and aircraft could deliver more than one 

ordnance item per sortie. The USWEXs could result in up to approximately 170 aircraft over-flights and 

ordnance drops per year on the Impact Area at PTA. Depending on the locations of the targets within the 

Impact Area, the time of day (early morning, evening, and night hours being more sensitive to noise 

impacts), and the types of ordnance, the Proposed Action could result in intrusive noise events. 

Each training event would last only a few hours, however, and the aggregate number of training days for 

the USWEXs would constitute less than 10 percent of the year. Therefore, even a large number of 

individually intrusive noise events would not substantially increase the long-term average equivalent 

noise level in the vicinity of PTA. In addition, the public exposure to this noise would be limited to a 

small number of employees and visitors to Mauna Kea State Park and Kilohana Girl Scout Camp. For 

these reasons, the effects of USWEX on the noise environment at PTA under Alternative 1 would be less 

than significant. 

4.1.4.5 Safety and Health—PTA—STWEX 

STWEX exercises occur routinely at PTA. The DoD takes every reasonable precaution during the 

planning and execution of the operation of training exercises to prevent injury to human life and wildlife, 

or damage to property. Specific safety plans are developed to ensure that each hazardous operation is in 

compliance with applicable policy and regulations and to ensure that the general public and range 

personnel and assets are provided an acceptable level of safety. 

Recent range studies at PTA have revealed elevated levels of munition byproducts, such as lead and RDX 

(cyclotrimethylenetrinitramine), above U.S. Environmental Protection Agency Region IX residential and 

industrial preliminary remediation goals at PTA. As defined in the Military Munitions Rule, ammunition 

used for its intended purpose on military ranges is not considered a regulated hazardous material but may 

be an environmental hazard. However, the analysis showed that the areas where the contamination occurs 

are in areas where the contamination is not running off-site. In addition, only government personnel or 

government contractors specifically trained and certified to travel safely in the impact area access the 

contaminated areas on a regular basis. (U.S. Army, 2004) 

All government personnel or government contractors accessing ordnance impact areas would continue to 

follow Occupational Safety and Health Administration and U.S. Army standards and guidelines to 

minimize health and safety impacts from exposure to any contaminants or ordnance (U.S. Department of 



the Army, 2004). The impact area is in an isolated area with restricted access located away from the 

civilian population. Safety and health precautions are covered in External Standard Operating Procedures 

and are briefed by the PTA Operations Center (U.S. Army Garrison, Hawaii, 1996). 

Impacts of USWEX exercises at PTA on safety and health are anticipated to be insignificant. 

4.1.5 Ocean Area, Hawaiian Islands 

4.1.5.1 Airspace—Ocean Area, Hawaiian Islands—ASMEX, ASWEX, GUNEX 

USWEX exercises would occur within existing Restricted Areas, Warning Areas, and Air Traffic Control 

Assigned Airspace areas under the control of PMRF and FACSFAC Pearl Harbor. USWEX exercises 

would be conducted in accordance with FACSFAC San Diego INST 3120.1D. PMRF and FACSFAC 

Pearl Harbor maintain surveillance and coordinate scheduling of the Hawaiian Fleet Operating Areas to 

ensure maximum utilization, coordination, and safety. PMRF is the using agency for Warning Areas W- 

186 and W-188 and Restricted Airspace R-3101, and FACSFAC Pearl Harbor is the using agency for 

Warning Areas W-187, W-189, W-190, W-191, W-192, W-193, W-194, and W-196, Restricted Airspace 

R-3107, and the Air Traffic Control Assigned Airspace areas shown on Figure 1-1. The easternmost 

section of Warning Area W-188 (Rainbow) has been sub-delegated from PMRF to FACSFAC Pearl 

Harbor. Scheduling responsibilities for the airspace has been divided between PMRF and FACSFAC 

Pearl Harbor as listed above for the using agency. FACSFAC San Diego INST 3120.1D includes a 

description of each operating area within the Hawaiian Islands Operating Area that includes the location, 

description, type of exercises, authorized ordnance, altitude, periods of usage, scheduling authority, 

communications frequencies, and special instructions including protected species considerations and 

restrictions. 

USWEX activities are similar to ongoing, continuing Fleet Training Exercises that utilize the existing 

over water airspace. No new special use airspace proposal or any modification to the existing special use 

airspace is contemplated to accommodate USWEX activities. Consequently, no impacts to the airspace 

over the open ocean have been identified from USWEX activities. 

4.1.5.2 Biological Resources—Ocean Area, Hawaiian Islands—ASMEX, ASWEX, 

GUNEX 

Essential Fish Habitat—In 2003, NMFS prepared a detailed description of non-fishing impacts to 

essential fish habitat and recommended conservation measures. Activities that may potentially impact 

EFH were identified as occurring in four discreet ecosystems: upland, riverine, estuarine, and 

coastal/marine systems. Broad categories of such activities include, but are not limited to, mining, 

dredging, fill, impoundment, discharge, water diversions, thermal additions, actions that contribute to 

non-point source pollution and sedimentation, introduction of potentially hazardous materials, 

introduction of exotic species, and the conversion of aquatic habitat that may eliminate, diminish, or 

disrupt the functions of EFH. 

None of the proposed training events identified for USWEX include activities similar to those identified 

as have a potential to affect EFH. Mid-frequency active tactical sonar would also not affect EFH waters 

or substrate and therefore an EFH Assessment is not required. 



Potential Non-ASW Impacts—Collisions with commercial and U.S. Navy ships may occasionally cause 

fatalities or major wounds to sea turtles and cetaceans. The most vulnerable marine mammals are those 

that spend extended periods of time at the surface in order to restore oxygen levels within their tissues 

after deep dives (e.g., sperm whale). Accordingly, the U.S. Navy has adopted standard operating 

procedures to reduce the potential for collisions with surfaced marine mammals and sea turtles. These 

standard operating procedures include: (1) use of lookouts trained to detect all objects on the surface of 

the water, including marine mammals and sea turtles; (2) reasonable and prudent actions to avoid the 

close interaction of U.S. Navy assets and marine mammals and sea turtles; and (3) maneuvering to keep 

away from any observed marine mammal. Based on these standard operating procedures, collisions with 

cetaceans, monk seals, and sea turtles are not expected. Personnel are aware that they are not to harm or 

harass marine mammals or sea turtles. As part of the required clearance before an exercise, the target area 

must be inspected visually and determined to be clear. The required clearance zones at the target areas, 

and exercises within controlled ranges at PMRF, keep the risk to marine mammals and sea turtles remote. 

Open ocean clearance procedures are the same for live or inert ordnance. Whenever ships and aircraft use 

PMRF’s range for missile and gunnery practice, the weapons are used under controlled circumstances 

involving clearance procedures to ensure whales, monk seals, or sea turtles are not present in the target 

area. These involve, at a minimum, a detailed visual search of the target area by aircraft reconnaissance, 

range safety boats, and range controllers supplemented by radar and the hydrophones on the range. 

Ordnance cannot be released until the target area is determined clear. Operations are immediately halted 

if whales, monk seals, or sea turtles are observed within the target area. Operations are delayed until the 

animal clears the target area. All observers are in continuous communication in order to have the 

capability to immediately stop the operations. The exercise can be modified as necessary to obtain a clear 

target area, or it is canceled. Procedures in open ocean areas outside PMRF ranges are similar to those 

described above. All of these factors serve to avoid the risk of harming whales, monk seals, or sea turtles. 

The weapons used in most missile and GUNEX exercises pose little risk to whales, monk seals, or sea 

turtles unless they were to be near the surface at the point of impact. Both 0.50-caliber machine guns and 

the close-in weapons systems exclusively fire non-explosive ammunition. The same applies to larger 

weapons firing inert ordnance for training exercises. These rounds pose a risk only at the point of impact. 

Target area clearance procedures would again reduce this risk. 

A marine mammal or sea turtle might momentarily change its behavior if overflown by a drone at low 

altitude, but this effect would be a random, transitory event. There is no information presently available 

which indicates any indirect impacts from these types of activities on marine mammals or sea turtles. 

(Pacific Missile Range Facility, Barking Sands, 1998) 

Potential ASW Impacts—Anti-submarine warfare is the primary role for U.S. Navy patrol aircraft and 

anti-submarine warfare helicopters. Anti-submarine warfare aircrews must practice using sensors, 

including electro-optical devices, radar, magnetic anomaly detectors, sonar (including helicopter dipping 

sonar and both active and passive sonobuoys) in both the deep and shallow water environment. 

The training events being analyzed for Alternative 1 are not new and have taken place in the Hawaiian 

Islands Operating Area over at least the past 40 years with no significant changes. However, marine 

mammal research and additional scientific information has led to the ability to quantitatively assess 

potential effects on marine mammals through the use of newly derived threshold criteria. As a result of 

scientific advances in acoustic exposure effects-analysis modeling on marine mammals, action proponents 



now have the ability to quantitatively estimate cumulative acoustic exposure on marine mammals. Due to 

these advances in scientific information, modeling has been conducted to support an effects-analysis on 

marine mammals that may be affected by the USWEX training events that use mid-frequency active 

tactical sonar. 

The approach for estimating potential acoustic effects from USWEX ASW training activities on cetacean 

species makes use of the methodology that was developed in cooperation with NOAA for the U.S. Navy’s 

Draft Overseas Environmental Impact Statement/Environmental Impact Statement, Undersea Warfare 

Training Range (OEIS/EIS) and the 2006 Supplement to the 2002 Rim of the Pacific (RIMPAC) 

Programmatic Environmental Assessment (U.S. Department of the Navy, Commander, Atlantic Fleet, 

2005, and U.S. Department of the Navy, Commander, Pacific Fleet, 2006). The modeling for this 

EA/OEA has been expanded to include marine mammal depth information and three dimensional 

ensonification. Acoustic exposure effects-analysis modeling will continue to evolve as researchers, 

modelers, and specialists within academia, the U.S. Navy, and NOAA continue to coordinate their efforts. 

The methodology used for this EA/OEA includes the following topics which are discussed in detail in the 

sections that follow: 

• Acoustic Effects on Fish 

• Acoustic Effects on Marine Mammals - Regulatory Framework 

• Indicators of physiological effects and determination of sound energy measurement units 

• Defining physiological thresholds 

• Defining behavioral thresholds 

• Consideration of prolonged exposure and masking 

• Applying the effect thresholds to a range of species 

• Implementing an acoustic effect analysis model 

• Evaluating the results of the acoustic effects model relative to the regulatory framework 

4.1.5.2.1 Acoustic Effects on Fish 

As discussed in Section 3.5.2.2, behavioral studies have shown that most fish only detect sound within the 

1-3 kHz (1,000 to 3,000 Hz) frequency range. USWEX mid-frequency active tactical sonar transmits at 

center frequencies of 2.6 kHz and 3.3 kHz. Thus, it is expected that most fish species would be able to 

detect the mid-frequency sonar only at the upper end of their hearing range. The results of several studies 

have indicated that acoustic communication and orientation of fishes, in particular of hearing specialists, 

may be limited by noise regimes in their environment. Further, some fish may respond behaviorally to 

varying sound frequencies. 

Although it is expected that most fish species would be able to detect the USWEX mid-frequency sonar, 

significant effects on fish are not anticipated with implementation of the Proposed Action. There is no 

information available that suggests that exposure to non-impulsive acoustic sources results in fish 

mortality. While experiments have shown that exposure to loud sound can result in significant threshold 

shifts in certain fish that are classified as hearing specialists (but not those classified as hearing 

generalists), these threshold shifts are temporary, and it is not evident that they lead to any long-term 

behavioral disruptions. 



Further, while fish may respond behaviorally to mid-frequency sources (similar to the sonar sources that 

would be used during USWEX), this behavioral modification is only expected to be brief and not 

biologically significant. Additionally, review of the available literature appears to indicate that low and 

high frequency acoustic sources are more likely to result in behavioral modifications in fish than are midfrequency 

acoustic sources. Research by Gearin et al., (2000) and Culik et al., (2001) indicated the midfrequency 

sound from acoustic devices designed to deter marine mammals from gillnet fisheries were 

either inaudible to fish or, the fish were not disturbed by the sound. 

Based on the evaluation of the data presented above, significant effects on fish are not anticipated from 

the use of mid-frequency sonar during USWEX. 

4.1.5.2.2 Acoustic Effects on Marine Mammals—Regulatory Framework 

This section presents the regulatory framework within which potential effects can be categorized. Both 

the Marine Mammal Protection Act (MMPA), as amended, and the ESA direct which traits should be 

used when determining effects. Effects that address injury may be considered Level A harassment under 

MMPA. Effects that address behavioral and temporary non-injurious physiological disruption may be 

considered Level B harassment under MMPA. For ESA, effects that address injury are considered harm 

(an act which actually kills or injures fish or wildlife). Effects that address behavior are defined as an 

intentional or negligent act or omission which creates the likelihood of injury to wildlife by annoying it to 

such an extent as to significantly disrupt normal behavioral patterns which include, but are not limited to, 

breeding, feeding, or sheltering. Under ESA there are also behavioral effects that exceed the normal daily 

variation in behavior, but which arise without an accompanying physiological effect. 

The Navy is preparing an Environmental Impact Statement (EIS) for the Hawaiian Range Complex 

(HRC). In a draft EIS (DEIS) provided to the public for review and comment, the Navy and NMFS (as a 

cooperating agency) solicited comment on a "dose-function" modeling methodology for assessing the 

probability of marine mammals being behaviorally harassed by potential exposure to mid-frequency 

active sonar. Because Navy has not yet issued a Record of Decision for the Hawaii Range Complex EIS, 

and NMFS has not promulgated the use of the dose-function model through its rule-making process, the 

USWEX EA/OEA uses the existing energy flux density methodology for assessing behavioral and 

physiological effects. 

In 2004, Congress amended the definition of harassment under the MMPA for military readiness 

activities, such as this action. For military readiness activities, Level A harassment under the MMPA 

includes any act that injures or has the significant potential to injure a marine mammal or marine mammal 

stock in the wild. Injury, as defined by previous National Oceanic and Atmospheric Administration 

rulings (2001; 2002a) and in the Undersea Warfare Training Range Draft OEIS/DEIS (U.S. Department 

of the Navy, Commander, U.S. Fleet Forces, 2005) is the destruction or loss of biological tissue. The 

destruction or loss of biological tissue will result in an alteration of physiological function that exceeds 

the normal daily physiological variation of the intact tissue. 

For military readiness activities, Level B harassment the 2004 amendments to the MMPA is “any act that 

disturbs or is likely to disturb a marine mammal or marine mammal stock in the wild by causing 

disruption of natural behavioral patterns including, but not limited to, migration, surfacing, nursing, 

breeding, feeding, or sheltering to a point where such behavioral patterns are abandoned or significantly 

altered. 



The applicable definition of Level B harassment served to clarify and codify NMFS’ pre-existing 

regulatory interpretation of Level B harassment, which properly focused on activities that had the 

potential to result in significant behavioral changes in biologically important activities, rather than 

activities with de minimus impacts. The U.S. Navy and NMFS believe that replacement of the threshold 

standard “potential” with “likely” eliminates from consideration activities with a mere “potential” to have 

impacts. Unlike Level A harassment, which is solely associated with injurious physiological effects, both 

temporary non-injurious physiological and behavioral effects may cause Level B harassment. 

The intent of the definition of harassment for military readiness activities and specific scientific activities 

was to provide greater clarity for the DoD and the regulatory agencies, and to properly focus 

authorization of military readiness and scientific research activities on such biologically significant 

impacts to marine mammals, a science-based approach. 

As described above and as required by NMFS during consultation on the RIMPAC 2006 sonar modeling, 

the analysis in this EA/OEA assumes that short-term non-injurious sound exposure levels predicted to 

cause Temporary Threshold Shift (TTS) or temporary behavioral disruptions qualify as Level B 

harassment. Application of this criterion assumes an effect even though not every behavioral disruption 

or instance of TTS will result in the abandonment or significant alteration of behavioral patterns. 

4.1.5.2.3 Indicators of Physiological Effects (PTS and TTS) 

Very high sound levels may rupture the eardrum or damage the small bones in the middle ear of mammals 

(Yost, 1994). Lower sound levels may cause permanent or temporary hearing loss. Such an effect is 

called a threshold shift (TS). ATS may be either permanent or temporary. Permanent Threshold Shift 

(PTS) is used as the criteria for physiological effects resulting in injury, and TTS is used as the criteria for 

physiological effects that do not result in injury but may result in a behavioral disturbance or in 

harassment. 

4.1.5.2.4 Use of Energy Flux Density Level for Physiological Effect Thresholds 

Energy Flux Density Level (EL) is a measure of the sound energy flow per unit area expressed in dB. EL 

is stated in dB re 1 µPa 2 -s for underwater sound. Sound Pressure Level (SPL) is a measure of the root 

mean square, or “effective”, sound pressure in decibels. SPL is expressed in dB re 1 µPa for underwater 

sound. Marine and terrestrial mammal data show that, for continuous-type sounds of interest, TTS and 

PTS are more closely related to the energy in the sound exposure than to the exposure SPL. 

The EL for each individual ping is calculated from the following equation: 

EL = SPL + 10log 10 (duration) 

The EL includes both the ping SPL and duration. Longer-duration pings and/or higher-SPL pings will 

have a higher EL. 

If a marine mammal is exposed to multiple pings, the energy flux density in each individual ping is 

summed to calculate the total EL. Since mammalian TS data show less effect from intermittent exposures 

compared to continuous exposures with the same energy (Ward, 1997), basing the effect thresholds on the 

total received EL is a conservative approach for treating multiple pings; in reality, some recovery will 

occur between pings and lessen the effect of a particular exposure. Therefore, estimates are conservative 



because recovery is not taken into account—intermittent exposures are considered comparable to 

continuous exposures. 

4.1.5.2.5 Comparison to Surveillance Towed Array Sensor System Low Frequency Active Risk 

Functions 

The effect thresholds described in this USWEX EA/OEA should not be confused with criteria and 

thresholds used for the U.S. Navy’s Surveillance Towed Array Sensor System Low Frequency Active 

(SURTASS LFA) sonar (National Oceanic and Atmospheric Administration, 2002a). SURTASS LFA 

features pings lasting many tens of seconds. The sonars of concern for use during USWEX emit pings 

lasting less than 1 second. SURTASS LFA risk functions were expressed in terms of the received SPL. 

Effect thresholds for USWEX are expressed in terms of the total received EL. The SURTASS LFA risk 

function parameters cannot be directly compared to the effect thresholds proposed in this document. 

4.1.5.2.6 TTS and PTS Effect Thresholds 

The TTS threshold is primarily based on the cetacean TTS data from Schlundt et al. (2000). Since these 

tests used short-duration tones similar to sonar pings, they are the most directly relevant data. The mean 

exposure EL required to produce onset-TTS in these tests was 195 dB re 1 µPa 2 -s. This result is 

corroborated by the short-duration tone data of Finneran et al. (2000, 2003a, 2005) and the long-duration 

noise data from Nachtigall et al. (2003a, 2003b). Together, these data demonstrate that TTS in cetaceans 

is correlated with the received EL and that onset-TTS exposures equate to an energy level of 195 dB re 1 

µPa 2 -s. 

Generating precise PTS data for marine mammals poses moral and ethical issues due to the requirement 

that experiments be conducted that result in actual injury and/or death of marine mammals. Scientists 

overcome this dilemma by making extrapolations from behavioral effects data that err on the side of 

concluding that injury occurs at thresholds lower than scientists believe injury may occur. Therefore, 

PTS levels for marine mammals were estimated using TTS data and relationships between TTS and PTS. 

The 215 dB re 1 µPa 2 -s PTS threshold is based on a 20 dB increase in exposure EL over that required for 

onset-TTS. The 20 dB value is based on extrapolations from terrestrial mammal data indicating that PTS 

occurs at 40 dB or more of TS, and that TS growth occurs at a rate of approximately 1.6 dB TTS per dB 

increase in EL. There is a 34 dB TS difference between onset-TTS (6 dB) and onset-PTS (40 dB). The 

additional exposure above onset-TTS that is required to reach PTS is therefore 34 dB divided by 1.6 dB, 

or approximately 21 dB. This estimate is conservative because (1) 40 dB of TS is actually an upper limit 

for TTS used to approximate onset-PTS, and (2) the 1.6 dB/dB growth rate is the upper range of values 

from Ward et al. (1958, 1959). 

4.1.5.2.7 Behavioral Effects 

The U.S. Navy proposes a behavioral effects threshold of 190 dB re 1 μPa 2 -s, based primarily on the 

behavioral observations reported in Schlundt et al. (2000) and Finneran et al. (2000, 2003b, 2005). 

Finneran and Schlundt (2004) summarize these data and provide the statistical analysis used in 

development of this threshold. These studies are applicable because they used short-duration tones and 

frequencies similar to the sonar use modeled in this assessment. The most compelling reason for the use 

of these experimental data using captive animals was the considerable number of studies involved and the 

absence of any other data using representative sound characteristics and experimental controls. In 

particular, the studies summarized in Finneran and Schlundt (2004) and their resulting analysis provides 

the most appropriate data to develop a behavioral effects threshold because: (1) researchers had superior 



control over and ability to quantify noise exposure conditions; (2) behavioral patterns of exposed marine 

mammals were readily observable and definable; (3) fatiguing noise consisted of tonal noise exposures 

with frequencies contained in the tactical mid-frequency sonar bandwidth; and (4) the species involved 

were closely related to the majority of the marine mammals expected to be within the Hawaiian Islands 

operational areas. Since no directly comparable data exist, or are likely to be obtained, for marine 

mammals in the wild, the relationship between the behavioral results reported by Finneran and Schlundt 

(2004) and marine mammals in the wild is unknown. However, data from wild cetaceans exposed to midfrequency 

sonar and sounds similar to mid-frequency sonar have been collected, and these data were also 

considered by NMFS in the development of behavioral effects criteria. Although, experienced, trained 

subjects may tolerate higher sound levels than inexperienced animals, it is also possible that prior 

experiences and resultant expectations may have made some trained subjects less tolerant of the sound 

exposures (see Domjan, 1998). The following paragraphs discuss the applicability of the Finneran and 

Schlundt (2004) data. 

As described in Finneran and Schlundt (2004), the behavior of a subject during intense sound exposure 

experiments was subjectively compared to the subject’s “normal” behaviors to determine whether a 

subject exhibited altered behavior during a session. In this context, altered behavior means a deviation 

from a subject’s typical trained behaviors. The subjective assessment was only possible because 

behavioral observations were made with the same subjects during many baseline hearing sessions with no 

intense sound exposures. This allowed comparisons to be made between how a subject usually acted and 

how it acted during test sessions with intense sound exposures. Each exposure session was then 

categorized as “normal behavior” or “altered behavior.” The behavioral alterations primarily consisted of 

reluctance on the part of the subjects, during a test session, to return to the site of a previous intense sound 

exposure. All instances of altered behavior were included in the statistical summary. An example of the 

results is as follows: At 192 dB re 1 µPa exposure SPL, 7 of 13 white whale sessions and 16 of 32 

dolphin sessions were categorized as altered behavior. The pooled percentage is therefore 51%, or 23 of 

45 total sessions. 

Exposure levels corresponding to sessions with 25, 50, and 75% altered behavior were 180, 190, and 199 

dB re 1 µPa SPL (or 180, 190, and 199 dB re 1 µPa 2 -s EL), respectively, for the frequency range of 3 to 

20 kHz, which is the range of frequencies that will be used in USWEX. More detailed statistical results 

are provided in Finneran and Schlundt (2004). 

The use of the 50% point (190 dB re 1 μPa 2 -s) to estimate a single numeric “all-or-nothing” threshold 

from a psychometric function is a common and accepted psychophysical technique (e.g., Nachtigall et al., 

2000; Yost, 1994). The 50% altered point from these data is one approach to predicting Level B 

harassment because it actually represents the sensory threshold point where the sound was strong enough 

to potentially result in altered behavior in the captive animals 50% of the time; however, it may not result 

in significantly altered behavior as is required to be considered Level B harassment as defined for military 

readiness activities. 

Although wide-ranging in terms of sound sources, context, and type/extent of observations reported, 

NMFS believes that the large and growing body of literature regarding behavioral reactions of wild, naïve 

marine mammals to anthropogenic exposure generally suggests that wild animals are behaviorally 

affected at significantly lower levels than those determined for captive animals by Finneran and Schlundt 

(2004). For instance, cetaceans exposed to human noise sound sources, such as seismic airgun sounds 

and low frequency sonar signals, have been shown to exhibit avoidance behavior when the animals are 



exposed to noise levels of 140-160 dB re 1 μPa under certain conditions (Malme et al., 1983; 1984; 1988; 

Ljungblad et al., 1988; Tyack and Clark, 1998). Two specific situations for which exposure conditions 

and behavioral reactions of free-ranging marine mammals exposed to sounds somewhat similar to those 

proposed for use in USWEX were considered by Nowacek et al. and NMFS in 2004 (Nowacek et al., 

2004 and National Marine Fisheries Service, Pacific Islands Fisheries Science center, 2004). Both 

suggest behavioral alterations, including the alteration of feeding, diving, and social behavior, occur at 

levels below the 190 dB re 1 μPa 2 -s criterion (acknowledging differences in metrics). 

Nowacek et al. (2004) conducted controlled exposure experiments on North Atlantic right whales using 

ship noise, social sounds of con-specifics, and an alerting stimulus (frequency modulated tonal signals 

between 500 Hz and 4.5 kHz). Animals were tagged with acoustic sensors (D-tags) that simultaneously 

measured movement in three dimensions. Whales reacted strongly to alert signals at received levels of 

133-148 dB SPL, mildly to conspecific signals, and not at all to ship sounds or actual vessels. The alert 

stimulus caused whales to immediately cease foraging behavior and swim rapidly to the surface. 

Although sound exposure level values were not directly reported, based on received exposure durations, 

approximate received values were on the order of 160 dB re 1 μPa 2 -s. However, the frequencies used, the 

modulated tones, and the long duration of the alert stimuli are not the same as U.S. Navy mid-frequency 

sonar and were designed specifically to create a behavioral reaction in North Atlantic right whales. 

NMFS notes the fact that pure tone exposures in laboratory conditions differ physically in several 

substantive ways from received tactical sonar signals in real-world conditions. Although pure tone 

exposures used in the captive TTS studies are certainly more like tactical mid-frequency sonar than 

certain human sound sources (such as vessels or ice-breaking) involved in less-controlled behavioral 

studies of wild animals, there are some potentially significant differences between these laboratory noise 

exposures and the complex frequency modulation and multi-path propagation patterns of tactical sonars in 

operational environments. Last, there is considerable uncertainty regarding the validity of applying data 

collected from trained captives conditioned to not respond to noise exposure in setting thresholds for 

behavioral reactions of naïve wild individuals to a sound source that apparently evokes strong reactions in 

some marine mammals. However, it is also possible that prior experiences and resultant expectations 

may have made some trained subjects less tolerant of the sound exposures (see Domjan, 1998). 

Given these considerations, NMFS believes that a more conservative acoustic behavioral disturbance 

threshold for sub-TTS behavioral disturbance than the 190 dB re 1 μPa 2 -s criterion is necessary. 

Acknowledging the quantitative limitations of many of the field observations of marine mammals and the 

advantages in this regard of the Finneran and Schlundt (2004) analysis, NMFS has set the behavioral 

effects threshold at 173 dB re 1 μPa 2 -s. For this USWEX EA/OEA the U.S. Navy will consider both the 

190 dB re 1 μPa 2 -s and 173 dB re 1 μPa 2 -s threshold criteria for sub-TTS behavioral Level B exposure. 

The selection of these threshold criteria and their use in this document is not intended to serve as 

precedent for any future U.S. Navy request for Letter of Authorization, biological opinion, or incidental 

take statement. Establishment of a revised threshold for analysis will continue to be coordinated between 

NMFS and the U.S. Navy for future actions undertaken pursuant to MMPA based on the advancement of 

science in this regard. 



4.1.5.2.8 Likelihood of Prolonged Exposure 

The proposed ASW activities during USWEX would not result in long-term effects because the vessels 

are constantly moving, the USWEX is conducted over 3 to 4 days, and the flow of the activity in the 

Hawaiian Islands Operating Area when ASW training occurs reduces the potential for prolonged 

exposure. The implementation of the protective measures described in Chapter 5 would further reduce 

the likelihood of any prolonged exposure. 

4.1.5.2.9 Likelihood of Masking 

Natural and artificial sounds can disrupt behavior by masking, or interfering with an animal’s ability to 

hear other sounds. Masking occurs when the receipt of a sound is interfered with by a second sound at 

similar frequencies and at similar or higher levels. If the second sound were artificial, it could be 

potentially harassing if it disrupted hearing-related behavior such as communications or echolocation. It 

is important to distinguish TTS and PTS, both of which persist after the sound exposure, from masking, 

which occurs during the sound exposure. 

Historically, principal masking concerns have been with prevailing background noise levels from natural 

and manmade sources (for example, Richardson et al., 1995). Dominant examples of the latter are the 

accumulated noise from merchant ships and noise of seismic surveys. Both cover a wide frequency band 

and are long in duration. 

The proposed USWEX areas are away from harbors and the most heavily traveled shipping lanes. The 

loudest mid-frequency underwater sounds in the Hawaiian Islands Operating Area are those produced by 

hull-mounted mid-frequency active tactical sonar. The sonar signals are likely within the audible range of 

most cetaceans, but are very limited in the temporal and frequency domains. In particular, the pulse 

lengths are short, the duty cycle low, and these hull-mounted mid-frequency active tactical sonars 

transmit within a narrow band of frequencies (typically less than one-third octave). 

For the reasons outlined above, the chance of sonar operations causing masking effects is considered 

negligible. 

4.1.5.2.10 Application of Effect Thresholds to Other Species 

Mysticetes and Odontocetes 

Information on auditory function in mysticetes is extremely lacking. Sensitivity to low-frequency sound 

by baleen whales has been inferred from observed vocalization frequencies, observed reactions to 

playback of sounds, and anatomical analyses of the auditory system. Baleen whales are estimated to hear 

from 15 Hz to 20 kHz, with good sensitivity from 20 Hz to 2 kHz (Ketten, 1998). Filter-bank models of 

the humpback whale’s ear have been developed from anatomical features of the humpback’s ear and 

optimization techniques (Houser et al., 2001). The results suggest that humpbacks are sensitive to 

frequencies between 40 Hz and 16 kHz, but best sensitivity is likely to occur between 100 Hz and 8 kHz. 

However, absolute sensitivity has not been modeled for any baleen whale species. Furthermore, there is 

no indication of what sorts of sound exposure produce threshold shifts in these marine mammals. 

The criteria and thresholds for PTS and TTS developed for odontocetes for this activity are also used for 

mysticetes. This generalization is based on the assumption that the empirical data at hand are 

representative of both groups until data collection on mysticete species shows otherwise. For the 



frequencies of interest for this action, there is no evidence that the total amount of energy required to 

induce onset-TTS and onset-PTS in mysticetes is different than that required for odontocetes. 

Beaked Whales 

Recent beaked whale strandings have prompted inquiry into the relationship between mid-frequency 

active tactical sonar and the cause of those strandings. Several suggested causes of those strandings are 

described in Section 4.1.5.2.7. In the one stranding where U.S. Navy mid-frequency active tactical sonar 

has been identified as a plausible contributory source to the stranding event (in the Bahamas in 2000), the 

U.S. Navy participated in an extensive investigation of the stranding with NMFS (U.S. Department of 

Commerce and U.S. Department of the Navy, 2001). The specific mechanisms that led to the Bahamas 

stranding are not understood and there is uncertainty regarding the ordering of effects that led to the 

stranding. 

The “Joint Interim Report, Bahamas Marine Mammal Stranding Event of 15-16 March 2000” (U.S. 

Department of Commerce and U.S. Department of the Navy, 2001) concluded that environmental and 

biological factors, including (1) intensive use of multiple sonar units; (2) whale presence, especially 

beaked whale species; (3) surface duct presence; (4) high relief bathymetry such as seamounts and 

canyons; and (5) a constricted channel with limited egress (approximately 19 nm wide by 100 nm long) 

were contributory factors to the Bahamas stranding. 

There have been several other stranding events involving use of mid-frequency active sonar by other 

nations where it appears such sonar use was a factor in the strandings, including one associated with use 

of a NATO system that included a mid-frequency active sonar component in Greece in 1996, and 

strandings associated with use of mid-frequency active-only systems in Madeira in 2000, the Canary 

Islands in 2002, and Spain in 2006. As is the case with the Bahamas strandings, however, it appears that 

the strandings were also related to the presence of certain environmental conditions (e.g., lack of egress, 

steep-walled bathymetry). 

During the USWEX there will be intensive use of multiple sonar units. Three beaked whale species may 

be present in the vicinity. A surface duct may be present in a limited area for a limited period of time. 

Most of the ASW training events take place in the deep ocean well removed from areas of high 

bathymetric relief. Although some of the training events will take place in such areas, none of the training 

events will take place in a location having a constricted channel with limited egress similar to the 

Bahamas. Consequently, the confluence of factors believed to contribute to the Bahamas stranding, and 

in some of the other stranding events discussed above, are not present in the Hawaiian Islands and will 

therefore not be present during USWEX. 

Separate and meaningful effects thresholds cannot be developed specifically for beaked whales because 

the exact causes of beaked whale strandings are currently unknown. However, this EA takes a 

conservative approach and treats all predicted behavioral disturbance of beaked whales as potential nonlethal 

injury. This conservative approach accounts for the lack of understanding as to why some beaked 

whales have been injured or died after stranding when exposed to mid-frequency active sonar in 

combination with other factors. Based on decades of ASW training having occurred in the Hawaiian 

Islands, including previous USWEX type exercises, and no evidence of any beaked whale strandings 

having occurred in the timeframe of those events or otherwise associated with any of those events, it is 

extremely unlikely that any significant behavioral response will result from the interaction of beaked 

whales and the use of sonar during the USWEX. 



4.1.5.2.11 Other Effects Considered 

Acoustically Mediated Bubble Growth 

A number of hypotheses, none of which have achieved a scientific consensus (despite suggestions to the 

contrary in some of the public comments), have arisen to attempt to explain the strandings that have 

occurred. One suggested cause of injury to marine mammals is rectified diffusion (Crum and Mao, 

1996), the process of increasing the size of a bubble by exposing it to a sound field. This process is 

facilitated if the environment in which the ensonified bubbles exist is supersaturated with gas. Repetitive 

diving by marine mammals can cause the blood and some tissues to accumulate gas to a greater degree 

than is supported by the surrounding environmental pressure (Ridgway and Howard, 1979). Deeper and 

longer dives of some marine mammals (for example, beaked whales) are theoretically predicted to induce 

greater supersaturation (Houser et al., 2001). If rectified diffusion were possible in marine mammals 

exposed to high-level sound, conditions of tissue supersaturation could theoretically speed the rate and 

increase the size of bubble growth. Subsequent effects due to tissue trauma and emboli would 

presumably mirror those observed in humans suffering from decompression sickness. 

It is unlikely that the short duration of sonar pings would be long enough to drive bubble growth to any 

substantial size, if such a phenomenon occurs. However, an alternative but related hypothesis has also 

been suggested: stable bubbles could be destabilized by high-level sound exposures such that bubble 

growth then occurs through static diffusion of gas out of the tissues. In such a scenario the marine 

mammal would need to be in a gas-supersaturated state for a long enough period of time for bubbles to 

become of a problematic size. Yet another hypothesis has speculated that rapid ascent to the surface 

following exposure to a startling sound might produce tissue gas saturation sufficient for the evolution of 

nitrogen bubbles (Jepson et al., 2003). In this scenario, the rate of ascent would need to be sufficiently 

rapid to compromise behavioral or physiological protections against nitrogen bubble formation. 

Collectively, these hypotheses can be referred to as “hypotheses of acoustically mediated bubble growth.” 

Although theoretical predictions suggest the possibility for acoustically mediated bubble growth, there is 

considerable disagreement among scientists as to its likelihood (Piantadosi and Thalmann, 2004; Evans 

and Miller, 2004). To date, ELs predicted to cause in vivo bubble formation within diving cetaceans have 

not been evaluated (National Oceanic and Atmospheric Administration, 2002a). Further, although it has 

been argued that traumas from recent beaked whale strandings are consistent with gas emboli and bubbleinduced 

tissue separations (Jepson et al., 2003), there is no conclusive evidence of this. It should be noted 

that no marine mammals other than beaked whales have demonstrated the suite of injuries observed in the 

Bahamas and Canary Island events. 

Several comments on the draft EA suggested that marine mammals may be injured or killed by midfrequency 

active sonar and sink to the bottom of the ocean without being noticed. It is possible that some 

animals that die deep beneath the surface may be held down by hydrostatic pressure, but the idea that 

most marine mammals that die at sea sink, do not re-float, and thus are never seen is unsupported by any 

empirical evidence. 

Because evidence supporting the bubble growth and related theories is debatable, no marine mammals 

addressed in this EA are given special treatment due to the possibility for acoustically mediated bubble 

growth. Beaked whales are, however, assessed differently from other species to account for factors that 

may have contributed to prior beaked whale strandings as set out in the previous section. 



Resonance 

Another suggested cause of injury in marine mammals is air cavity resonance due to sonar exposure. 

Resonance is a phenomenon that exists when an object is vibrated at a frequency near its natural 

frequency of vibration—the particular frequency at which the object vibrates most readily. The size and 

geometry of an air cavity determine the frequency at which the cavity will resonate. Displacement of the 

cavity boundaries during resonance has been suggested as a cause of injury. Large displacements have 

the potential to tear tissues that surround the air space (for example, lung tissue). 

Understanding resonant frequencies and the susceptibility of marine mammal air cavities to resonance is 

important in determining whether certain sonars have the potential to affect different cavities in different 

species. In 2002, NMFS convened a panel of government and private scientists to address this issue 

(National Oceanic and Atmospheric Administration, 2002b). They modeled and evaluated the likelihood 

that U.S. Navy mid-frequency active tactical sonar caused resonance effects in beaked whales that 

eventually led to their stranding (U.S. Department of Commerce and U.S. Department of the Navy, 2001). 

The conclusions of that group were that resonance in air-filled structures was not likely to have caused the 

Bahamas stranding (National Oceanic and Atmospheric Administration, 2002b). The frequencies at 

which resonance was predicted to occur were below the frequencies utilized by the sonar systems 

employed. Furthermore, air cavity vibrations due to the resonance effect were not considered to be of 

sufficient amplitude to cause tissue damage. By extension, for purposes of this USWEX EA/OEA similar 

phenomenon would not be problematic in other cetacean species for the USWEX ASW events. 

4.1.5.2.12 Acoustic Effects Analysis Modeling 

In order to estimate acoustic effects from the USWEX ASW operations, acoustic sources to be used were 

examined with regard to their operational characteristics. Systems with acoustic source levels below 205 

dB re 1 µPa @ 1 m were not included in the analysis given that at this source level (205 dB re 1 µPa @ 1 

m) or below, a 1-second ping would attenuate below the sub-TTS behavioral disturbance threshold of 173 

dB within a distance of about 100 m. As additional verification, sources at this level were examined 

typically using simple spreadsheet calculations to ensure that they did not need to be considered further. 

For example, a sonobuoy’s typical use yielded an exposure area that produced 0 marine mammal 

exposures based on the maximum marine mammal density. Such a source was called non-problematic 

and was not modeled in the sense of running its parameters through the environmental model (CASS), 

generating an acoustic footprint, etc. The proposed counter measures source level was less than 205 dB 

but its operational modes were such that a simple “look” was not applicable, and a separate study was 

conducted to ensure it did not need to be considered further. 

In addition, systems with an operating frequency greater than 100 kHz were not analyzed in the detailed 

modeling as these signals attenuate rapidly resulting in very short propagation distances. Acoustic 

countermeasures were previously examined and found not to be problematic. The AN/AQS 13 (dipping 

sonar) used by carrier-based helicopters was determined in the Environmental Assessment/Overseas 

Environmental Assessment of the SH-60R Helicopter/ALFS Test Program, October 1999 not to be 

problematic due to its limited use and very short pulse length (2-5 pulses of 3.5-700 millisecond). The 

Directional Command Activated Sonobuoy System (DICASS) sonobuoy was determined not to be 

problematic having a source level at 201 dB re 1 µPa @ 1m. These acoustic sources, therefore, did not 

require further examination in this analysis. 



Based on the information above, only hull-mounted mid-frequency active tactical sonar was determined 

to have the potential to affect marine mammals protected under the MMPA and ESA during USWEX 

ASW training events. 

Every active sonar operation includes the potential to harass marine animals in the neighboring waters. 

The number of animals exposed to potential harassment in any such action is dictated by the propagation 

field and the manner in which the sonar is operated (i.e., source level, depth, frequency, pulse length, 

directivity, platform speed, repetition rate). For USWEX, the sole relevant measure of potential harm to 

the marine wildlife due to sonar operation is the accumulated (summed over all source emissions) energy 

flux density received by the animal over the duration of the activity. 

The modeling for surface ship active tactical sonar occurred in five broad steps, listed below. Results 

were calculated based on the typical ASW activities planned for USWEX. Acoustic propagation and 

mammal population data are analyzed for both the summer and winter timeframe. Marine mammal 

survey data for the offshore area beyond 25 nm (Barlow 2003) and survey data for nearshore areas within 

25 nm (Mobley et al. 2000) provided marine mammal species density for modeling. 

Step 1. Environmental Provinces. The USWEX operating area is divided into six marine modeling 

areas, and each has a unique combination of environmental conditions. These are addressed by 

defining eight fundamental environments in two seasons that span the variety of depths, bottom types, 

sound speed profiles, and sediment thicknesses found in the USWEX operating areas. Each marine 

modeling area can be quantitatively described as a unique combination of these environments. 

Step 2. Transmission Loss. Since sound propagates differently in these eight environments, 

separate transmission loss calculations must be made for each, in both seasons. The transmission loss 

is predicted using CASS-GRAB sound modeling software. 

Step 3. Exposure Volumes. The transmission loss, combined with the source characteristics, gives 

the energy field of a single ping. The energy of over 10 hours of pinging is summed, carefully 

accounting for overlap of several pings, so an accurate average exposure of an hour of pinging is 

calculated for each depth increment. Repeating this calculation for each environment in each season 

gives the hourly ensonified volume, by depth, for each environment and season. 

Step 4. Marine Mammal Densities. The marine mammal densities for RIMPAC 2006 were given 

in two dimensions, but using sources such as the North Pacific Acoustic Laboratory EIS, the depth 

regimes of these marine mammals are used to project the two dimensional densities into three 

dimensions. 

Step 5. Exposure Calculations. Each marine mammal’s three dimensional density is multiplied by 

the calculated impact volume—to that marine mammal depth regime. This is the number of 

exposures per hour for that particular marine mammal. In this way, each marine mammal's exposure 

count per hour is based on its density, depth habitat, and the ensonified volume by depth. 

The movement of various units during an ASW event is largely unconstrained and dependent on the 

developing tactical situation presented to the commander of the forces. The planned sonar hours, by 

acoustic exposure modeling area, are given in Table B-1 of Appendix B, and its product with the hourly 

exposure count is the expected total exposures. 

The analysis estimated the sound exposure for marine mammals produced by each sonar training event in 

each of the six acoustic exposure model areas. While ASW events could occur throughout the 



approximate 210,000 nm 2 of the Hawaiian Islands Operating Area, most events would occur within the 

approximate 46,000 nm 2 of these six areas that were used for analysis as being representative of the 

marine mammal habitats and the bathymetric, seabed, wind speed, and sound velocity profile conditions 

within the entire Hawaiian Islands Operating Area. Appendix B includes detailed explanation of the 

above discussion, and the results of the acoustic effects analysis modeling. 

4.1.5.2.13 Acoustic Effects Criteria and Thresholds 

Table 4-1 and Figure 4-1 summarize the acoustic effects criteria and thresholds used in this assessment. 

The figure is intended to illustrate the general relationships between effects zones and does not represent 

the sizes or shapes of the actual zones. 

Criteria 

Table 4-1. Acoustic Effects Criteria and Thresholds 

Threshold 

MMPA Definitions 

ESA Definitions 

(dB re 1 µPa 2 -s EL) 

PTS 215 Level A Harm 

TTS 195 Level B Harassment 

Sub-TTS Behavioral 

190 (Navy) 

Level B 

Harassment 

disturbance without 

physiological effects 

173 (NMFS) 

MMPA—Marine mammals predicted to receive a sound exposure with EL of 215 dB re 1 µPa 2 -s or 

greater are assumed to experience PTS and are counted as potential Level A exposures. Marine mammals 

predicted to receive a sound exposure with EL greater than or equal to 195 dB re 1 µPa 2 -s but less than 

215 dB re 1 µPa 2 -s are assumed to experience TTS and are counted as potential Level B exposures. In 

addition, all marine mammals predicted to receive a sound exposure with EL greater than or equal to 173 

dB re 1 µPa 2 -s (190 dB re 1 µPa 2 -s Navy criteria) but less than 195 dB re 1 µPa 2 -s are assumed to 

experience temporary physiological disturbance and are also counted as potential Level B exposures. The 

only exception to this approach is the post-modeling consideration for beaked whales as described in 

Section 4.2.1.5. 

NOTE: Figure not to scale 

Figure 4-1. Summary of the Acoustic Effects Criteria and Thresholds 



ESA—Potential for injury constituting harm under the ESA—ESA regulations define harm as “an act 

which actually kills or injures” fish or wildlife (50 CFR § 222.102). Based on this definition, the criterion 

applied here is PTS, a permanent noise-induced hearing loss. PTS is non-recoverable and as defined 

within this analysis, must result from the destruction of tissues within the auditory system. In this 

analysis, the smallest amount of PTS (onset-PTS) is taken to be the indicator for the smallest degree of 

injury that can be measured. The acoustic exposure associated with onset-PTS (EL of 215 dB re 1 µPa2-s 

or greater) is used to define the outer limit of the zone within which listed species are considered to 

potentially experience harm. 

Potential for non-injurious physiological effects constituting harassment under the ESA—ESA 

regulations define harassment as an “intentional or negligent act or omission which creates the likelihood 

of injury to wildlife by annoying it to such an extent as to significantly disrupt normal behavioral patterns 

which include, but are not limited to, breeding, feeding, or sheltering” (50 CFR § 17.3). In this 

assessment, the smallest measurable amount of TTS, onset-TTS, is taken as the best indicator for slight 

temporary sensory impairment. TTS is recoverable and, as in past rule-making (National Oceanic and 

Atmospheric Administration, 2001; 2002a), is considered to result from the temporary, non-injurious 

distortion of hearing-related tissues. Because it is considered non-injurious, the acoustic exposure 

associated with onset-TTS (EL greater than or equal to 195 dB re 1 µPa 2 -s) is used to define the outer 

limit of the zone within which listed species are predicted to experience harassment attributable to 

physiological effects. This follows from the concept that even temporary hearing loss at a single 

frequency potentially affects a marine mammal’s ability to react normally to the sounds around it. 

Potential for behavioral effects without physiological effects constituting harassment under the ESA— 

Acoustic exposure may result in behavioral effects that exceed the normal daily variation in behavior, but 

which arise without an accompanying physiological effect. In this assessment, these effects are also 

considered “potential harassment” under the ESA. This “exposure zone” extends outward to include the 

region where behavioral disruption is predicted to occur. The acoustic exposure of EL greater than or 

equal to 173 dB re 1 µPa 2 -s (190 dB re 1 µPa 2 -s Navy criteria) is used to define the outer limit of the zone 

within which listed species are considered to potentially experience harassment attributable to behavioral 

effects without physiological effects. 

4.1.5.2.14 Estimated Acoustic Effects on Marine Mammals (MMPA) 

When analyzing the results of the acoustic exposure modeling to provide an estimate of effects, it is 

important to understand that there are limitations to the ecological data used in the model, and that the 

model results must be interpreted within the context of a given species’ ecology. 

When reviewing the acoustic effects modeling results, it is also important to understand that the estimates 

of marine mammal sound exposures are presented without consideration of standard protective operating 

procedures or the fact that there have been no confirmed acoustic effects on any marine species in 

previous USWEX–type exercises or from any other mid-frequency active tactical sonar training events 

within the Hawaiian Islands Operating Area. Only one event that may involve acoustic exposures 

occurred in Hanalei Bay in July 2004. 

As described in Section 4.1.5.2.6, all predicted Level B exposure of beaked whales is treated as non-lethal 

Level A exposure. All Level B exposure would be short term and temporary in nature. In addition, the 

short-term non-injurious exposures predicted to cause TTS or temporary behavioral disruptions are 

considered Level B exposure in this EA even though it is highly unlikely that the disturbance would be to 



a point where behavioral patterns are abandoned or significantly altered. The proposed USWEX would 

only occur for 3 to 4 days up to six times per year, further reducing the potential to affect marine 

mammals as a result of extended use over time. 

The modeling for USWEX analyzed the potential interaction of mid-frequency active tactical sonar with 

marine mammals that occur in the Hawaiian Islands Operating Area. Table 4-2 presents the summary 

results for a single USWEX. The results are presented by season (summer and winter) and location (ESG 

USWEX in areas 1, 2, and 3, CSG USWEX in Areas 4, 5, and 6). As shown in the table a single USWEX 

would result in 2,395 to 6,870 instances in which total energy accumulated is greater than or equivalent to 

173 dB re 1 µPa 2 -s or 149 to 339 instances in which total energy accumulated is greater than 190 dB re 1 

µPa 2 -s, depending on season and location. 

Table 4-2. Single USWEX Mid-Frequency Active Tactical Sonar 

Acoustic Model Results by Season 

Exposure Criterion ESG USWEX 

Modeling Areas 1, 2, 3 

CSG USWEX 

Modeling Areas 4, 5, 6 

Summer Winter Summer Winter 

Sub-TTS 173 dB 2,395 6,843 3,861 6,870 

Sub-TTS 190 dB 149 328 215 339 

TTS 195 dB 23 42 34 45 

The modeled exposure numbers by species and location are presented in Table 4-3 (173 dB sub-TTS 

threshold) and Table 4-4 (190 dB sub-TTS threshold) and indicate the potential instances in which total 

energy accumulated is greater than or equivalent to 173 or 190 dB re 1 µPa 2 -s during six USWEX per 

year as defined for Alternative 1. There are no predicted instances in which accumulated energy will 

exceed 215 dB re 1 µPa 2 -s. Therefore, all numbers on the table represent Level B exposures. The table 

includes the number of estimated exposures for each species within each USWEX ASW acoustic model 

area. The exposure estimates have been rounded to the nearest integer since an estimated exposure of 0.5 

< 1 < 1.5 marine mammals is considered one marine mammal for this EA/OEA. Appendix B presents the 

results of the marine mammal acoustic effect modeling conducted for USWEX. 



MARINE MAMMAL 

SPECIES 

Table 4-3. USWEX Alternative 1 Mid-Frequency Active Tactical Sonar 

Acoustic Model Results (173 dB) 

USWEX ASW MODELING AREA PER YEAR 

Sub-TTS (173 dB) Level B exposure 

TOTALS PER YEAR 

Sub-TTS 

1 2 3 4 5 6 

(173 dB) 

Total 

TTS (195 

dB) Total 

Rough-toothed dolphin 207 203 200 998 104 1,120 2,832 41 

Dwarf sperm whale 160 154 151 757 82 878 2,182 12 

Fraser’s dolphin 148 144 141 730 75 806 2,045 20 

†Cuvier’s beaked whale 110 107 105 500 57 611 1,490 6 

Spotted dolphin 191 233 259 1,232 71 757 2,743 26 

Striped dolphin 94 93 93 475 47 501 1,303 13 

Short-finned pilot whale 130 153 167 796 52 552 1,849 12 

Pygmy sperm whale 61 59 58 291 31 338 839 5 

*Sperm whale 68 67 66 291 35 379 905 3 

Bottlenose dolphin 54 65 72 341 21 223 775 7 

Melon-headed whale 29 31 32 154 14 148 408 2 

Spinner dolphin 133 181 211 974 39 418 1,957 18 

Risso’s dolphin 20 19 19 98 10 109 276 2 

†Blainville’s beaked 

whale 

21 21 21 100 10 110 285 1 

†Longman’s beaked 

whale 

6 6 6 28 3 35 85 0 

Pygmy killer whale 8 8 7 36 4 43 106 2 

Bryde’s whale 8 7 7 23 4 47 96 0 

Killer whale 5 5 5 24 3 29 71 1 

*Fin whale 4 4 4 11 2 23 48 0 

False killer whale 8 10 11 50 3 28 109 2 

*Sei whale 1 2 2 2 5 1 10 21 0 

*Blue whale 0 0 0 0 0 0 0 0 

Minke whale 0 0 0 0 0 0 0 0 

*Humpback whale 869 1,618 2,073 5,713 0 0 10,273 49 

*Monk seal 1 0 0 0 0 0 0 0 0 

Sub-TTS (173 dB) Total 2,337 3,191 3,710 13,627 668 7,167 30,699 

TTS Total 17 22 25 87 6 64 222 

Notes: 

* Endangered Species 

† Beaked whales 

1 

Calculated using percentage of fin whale Hawaiian stock. Sei is 44% of fin. Monk seal is 32% of fin. 



MARINE MAMMAL 

SPECIES 




Sub-TTS (190 dB) Level B Exposure 

1 2 3 4 5 6 

TOTALS PER YEAR 

Sub-TTS 

(190 dB) 

Total 

TTS 

(195 dB) 

Total 

Rough-toothed dolphin 14 13 12 48 8 87 183 41 

Dwarf sperm whale 8 7 7 29 5 50 105 12 

Fraser’s dolphin 11 10 9 36 6 68 139 20 

†Cuvier’s beaked whale 4 3 3 17 2 23 52 6 

Spotted dolphin 14 19 23 78 4 41 179 26 

Striped dolphin 7 6 6 24 4 41 89 13 

Short-finned pilot whale 8 11 12 44 3 29 106 12 


*Sperm whale 2 1 1 8 1 9 23 3 



Spinner dolphin 10 16 20 66 1 11 125 18 



whale 


whale 

1 1 1 4 0 4 10 1 

0 0 0 1 0 1 3 0 


Bryde’s whale 0 0 0 0 0 0 1 0 

Killer whale 0 0 0 1 0 2 4 1 

*Fin whale 0 0 0 0 0 0 0 0 


*Sei whale 1 0 0 0 0 0 0 0 0 

*Blue whale 0 0 0 0 0 0 0 0 

Minke whale 0 0 0 0 0 0 0 0 

*Humpback whale 34 63 81 245 0 0 423 49 

*Monk seal 1 0 0 0 0 0 0 0 0 

Sub-TTS (190 dB) Total 124 164 189 651 38 419 1585 

TTS Total 4 7 9 28 0 0 222 

Notes: 



1 




As Table 4-3 shows, endangered species with potential exposures to accumulated energy levels exceeding 

173 dB re 1 µPa 2 -s) are sperm whale, fin whale, sei whale, and humpback whale. As Table 4-4 shows, 

endangered species with potential exposures to accumulated energy levels exceeding 190 dB re 1 µ Pa 2 -s 

are sperm whale and humpback whale. Potential impacts to these species are discussed in Section 

4.1.5.2.16. Since the density of sei whales is unknown, potential sei whale exposures were calculated 

using the modeled number of fin whale exposures and the ratio of sei whale Hawaiian stock to the fin 

whale Hawaiian stock, to approximate the number of sei whale exposures. 

Although there are no density figures for blue whales or North Pacific right whales, given their rare 

occurrence and presumed relative low abundance, it is unlikely that modeling would result in predicting 

exposure. Minke whales occur seasonally in Hawaii from November through March; however, it is 

unlikely that modeling would result in predicting exposures. Humpback whales utilize Hawaiian waters 

as a major breeding ground during the winter season (November through April) but are not in the area 

during the summer and would not be exposed during the summer season (May through October). 

There have only been a few sightings of the Northern elephant seal in the Hawaiian Islands, and so they 

were not modeled given it is extremely unlikely they would be present in the main Hawaiian Islands 

during USWEX. 

As described in Section 4.1.5.2.6, beaked whales are due special concern given that a stranding event in 

the Bahamas Islands in 2000 and a few other less documented events in other areas of the world suggest 

that beaked whales may be particularly susceptible to being affected by mid-frequency active tactical 

sonar. Since the exact causes of the beaked whale stranding events are unknown, separate, meaningful 

impact thresholds cannot be derived specifically for beaked whales. However, this EA takes a 

conservative approach and treats all behavioral disturbance of beaked whales as a potential non-lethal 

injury. All potential Level B exposure of beaked whales is therefore counted as potential non-lethal Level 

A exposure. As shown in Tables 4-3 and 4-4, there are three species of beaked whales present in the 

Hawaiian Islands that were modeled as potentially being exposed to sound levels resulting in Level B 

exposure. Cuvier’s beaked whales (173 dB n=1,490, 190 dB n=52), Blainville’s beaked whales (173 dB 

n=285, 190 dB n=10), and Longman’s beaked whales (173 dB n=85, 190 dB n=3) had the potential to be 

affected. These sound exposure numbers are conservatively accounted for as non-lethal Level A 

exposure. Based on operational characteristics and environmental conditions, the predicted incidental 

exposures of beaked whales to acoustic energy from USWEX sources would not result in serious injury or 

mortality. In addition, there have been numerous other ASW training events in the Hawaiian Islands 

Operating Area without stranding of any beaked whale species. Thus the U.S. Navy concludes that the 

Proposed Action would not affect annual rates of recruitment or survival for beaked whales. 

When looking at the acoustic model results, it is important to remember that although not considered in 

the modeling, the protective measures described in Chapter 5 will reduce the likelihood of exposures. 


their vicinity. U.S. Navy ships always have two, although usually more, personnel on watch serving as 

lookouts. In addition to the qualified lookouts, the Bridge Team is present that at a minimum also 

includes an Officer of the Deck and one Junior Officer of the Deck whose responsibilities also include 

observing the waters in the vicinity of the ship. The U.S. Navy includes marine species awareness training 

for bridge and lookout personnel. Other observers may include crews of airborne helicopters and P-3 

aircraft who also observe the ocean surface for signs indicative of submarines. These aerial observers are 

to report marine mammal sightings to vessels engaged in the training events. 



It is the duty of the lookouts to report to the officer in charge, the presence of any object, disturbance, 

discoloration in the water (since they may be indicative of a submarine’s presence), or marine mammal 

within sight of the vessel. At night, personnel engaged in ASW training events may also employ the use 

of night vision goggles and infrared detectors, as appropriate that can also aid in the detection of marine 

mammals. Passive acoustic detection of vocalizing marine mammals is also used to alert bridge lookouts 

to the potential presence of marine mammals in the vicinity. Surface ships utilize a hydrophone that 

receives all sounds, such as marine mammal vocalizations, and transmit the sound to speakers located on 

the bridge and in the sonar station. When the mid-frequency sonar is not active, it is in receive mode and, 

in this passive mode, is continually monitored by the sonar operators. 

Consideration of negligible impact is required by NMFS to authorize incidental harassment of marine 

mammals. By definition, an activity has a “negligible impact” on a species or stock when it is determined 

that the total taking is not likely to reduce annual rates of adult survival or annual recruitment (i.e., 

offspring survival, birth rates). Additionally, the activity will not have an unmitigable adverse impact on 

the availability of such species or stock for taking for subsistence uses. The overall conclusion is that 

effects on marine mammal species or stocks from USWEX ASW training events would be negligible for 

the following reasons: 

• All acoustic exposures are within the non-injurious TTS or behavioral effects zone. Based on the 

Navy’s consideration of the best available scientific data and information, combined with the 

professional judgment and expertise of NMFS and Navy scientists and other experts, the evidence 

before the Navy does not provide a basis to expect any mortality or injury to result from these 

activities, the harassment can be reasonably expected not to adversely affect the species or stock 

through effects on annual rates of survival. 

• Although numbers presented in Table 4-3 and Table 4-4 represent estimated Level B exposures 

under the MMPA, as described above, application of conservative assumptions in the 

methodology likely results in an overestimated number of exposures by behavioral disturbance. 

Conservative methods include: Basing the effect thresholds on the total received EL is a 

conservative approach for treating multiple pings; in reality, some recovery will occur between 

pings and lessen the effect of a particular exposure; for purposes of the analysis, all surface ship 

sonars were modeled as equivalent to SQS-53, the U.S. Navy’s most powerful surface ship sonar, 

resulting in an overestimation of potential effects; and, sonar ping transmission durations were 

modeled as lasting 1 second per ping and omnidirectional when actual ping durations will be less 

than 1 second. 

• In addition, the model calculates exposures without taking into consideration standard protective 

measures, and is not indicative of a likelihood of either injury or harm. 

• Additionally, the protective measures described in Chapter 5 and required by the National 

Defense Exemption (NDE) under the MMPA signed by the Deputy Secretary of Defense are 

designed to reduce sound exposure of marine mammals to levels below those that may cause 

“behavioral disruptions.” 

The U.S. Navy has coordinated with NMFS to establish protective measures identified in the NDE. On 

January 23, 2007, the Deputy Secretary of Defense signed an NDE to exempt all military readiness 

activities that employ mid-frequency active sonar, either during major training exercises, or within 

established DoD maritime ranges or established operating areas, from compliance with the MMPA. This 

exemption covers activities for 2 years from the signing of the NDE. To adhere with the NDE, all exempt 



military readiness activities employing mid-frequency active sonar must follow required protective 

measures that were coordinated with NMFS. The NDE protective measures are included in the USWEX 

EA/OEA analysis (Section 5.1.3). 

4.1.5.2.15 Melon-Headed Whale Stranding Event in July 2004 

The following paragraphs are taken in part from the NOAA report regarding the Hanalei Bay event 

(Southall et al, 2006). On July 3-4, 2004, between 150-200 melon–headed whales (Peponocephala 

electra) occupied the shallow waters of Hanalei Bay, Kauai, Hawaii for over 28 hours. Attendees of a 

canoe blessing observed the marine mammals entering the bay in a single wave formation at 7:00 a.m. 

(local time) on July 3, 2004. The marine mammals were observed moving back into shore from the 

mouth of the Bay at 9:00 a.m. The usually pelagic marine mammals milled in the shallow confined bay 

and were returned to deeper water with human assistance. The marine mammals were herded out of the 

bay with the help of members of the community, the Hanalei Canoe Club, local and federal employees, 

and volunteers/staff with the Hawaiian Islands Stranding Response Group beginning at 9:30 a.m. on July 

4, 2004 and were out of sight by 10:30 a.m. 

Only one marine mammal, a calf, was known to have died (on July 5, 2004) following this event. The 

marine mammal was noted alive and alone in the Bay on the afternoon of July 4, 2004 and was found 

dead in the bay the morning of July 5, 2004. A combination of imaging, necropsy, and histological 

analyses was conducted on July 7, 2004 and found no evidence of infectious, internal traumatic, 

congenital, or toxic factors. Although cause of death could not be definitively determined, it is likely that 

maternal separation, poor nutritional condition, and dehydration contributed to the final demise of the 

marine mammal. Although it is unknown when the calf was separated from the female, the movement 

into the bay, the milling and re-grouping may have contributed to the separation or lack of nursing 

especially if the maternal bond was weak or this was the calf of a first-time mother. 

Environmental factors were analyzed for any anomalous occurrences that would have contributed to the 

marine mammals entering and remaining in Hanalei Bay. The bathymetry is similar to many other sites 

within the Hawaiian Island chain and dissimilar to that which has been associated with mass strandings in 

other parts of the United States. The weather conditions appear to be normal for this time of year with no 

fronts or other significant features noted. There was no evidence for unusual distribution or occurrence of 

predator or prey species, or unusual harmful algal blooms. Weather patterns and bathymetry that have 

been associated with mass strandings elsewhere were not found to occur in this instance. 

This event was spatially and temporally correlated with RIMPAC 2004 exercises. Official sonar training 

and tracking exercises in the PMRF warning area did not begin until approximately 8:00 a.m. (local time) 

on July 3 and were thus ruled out as a possible trigger for the initial movement into the bay. 

However, the six naval surface vessels transiting to the operational area on July 2 intermittently 

transmitted active sonar (for approximately 9 hours total from 1:15 p.m. to 12:30 a.m.) as they 

approached from the south. The potential for these transmissions to have triggered the whales’ movement 

into Hanalei Bay was investigated. Analyses with the information available indicated that marine 

mammals to the south and east of Kauai could likely have detected active sonar transmissions on July 2, 

and reached Hanalei Bay on or before 7:00 a.m. on July 3, 2004. However, data limitations regarding the 

position of the whales prior to their arrival in the bay, the magnitude of sonar exposure, behavioral 



responses of melon-headed whales to acoustic stimuli, and other possible relevant factors preclude a 

conclusive finding regarding the role of sonar in triggering this event. Propagation modeling suggests 

that transmissions from sonar use during the July 3 exercise in the PMRF warning area may have been 

detectable at the mouth of the bay. If the marine mammals responded negatively to these signals, it may 

have contributed to their continued presence in the bay. However, the marine mammals remained in the 

bay for almost 18 hours after the U.S. Navy ceased all active sonar transmissions on the afternoon of 

July 3, 2004. Finally, it is worth noting that a similar incident occurred on the exact same day, over 1,000 

miles away, off the coast of the Northern Marianas Islands, without the presence of sonar. 

While a statement in the conclusion section of the NOAA report considers the sonar transmissions that 

occurred 18 to 50 nm south of Kauai the day before the event a “plausible, if not likely,” contributing 

factor in what was likely a confluence of events, the U.S. Navy disagrees with that conclusion. Following 

the conclusion statement the NOAA report goes on to describe several problems with the conclusion. The 

absence of information on a number of key points is significantly restrictive. The limitations of available 

information regarding where marine mammals were prior to entering the bay, their previous potential 

exposure history to tactical mid-frequency sonar or other human sound sources, and key biological 

information such as the presence of anomalous predator or prey distributions preclude a single 

unequivocal conclusion. 

As presented in the NOAA report, key questions regarding the possibility that sonar transmissions were 

responsible for the stranding event remain unanswered. For instance, why would a single cetacean 

species exclusively respond in such a dramatic and coherent manner when, based on the analyses 

conducted by NOAA and by the U.S. Navy, and knowledge of Hawaiian cetacean abundance, many other 

marine mammals in the areas surrounding Kauai were also exposed to sonar signals on July 2-3 2004 

Another pressing question is why, given the apparent historical frequency of active, military sonar use in 

and around the Hawaiian Islands, such exposures have apparently not triggered similar events previously 

There are hypothetical explanations for these and other lingering questions (e.g., lack of previous 

concerted observational effort and the physical nature of the coastline and strong current patterns in the 

Hawaiian Islands that may limit the likelihood of detecting stranding events), but they too are strongly 

limited by the lack of information about both nominal behavior of this species and their reaction to natural 

and human sound sources. 

A declaration by the lead NOAA author, Brandon Southall, provides additional clarification of the 

conclusion of the report: “To be clear, and contrary to certain media and other characterizations, the 

carefully-worded and qualified Hanalei report event did not conclude that active military sonar caused 

this event. We do not know what caused it. The report stated that based on the information available, 

sonar may have contributed to a “confluence of events,” including human presence (notably the 

uncontrolled and random human interactions fragmenting the pod of whales on 3 July) and/or other 

unknown biological or physical factors. There have been various interpretations of the strength of 

evidence regarding whether sonar played some role in the event. It should be clearly stated that our report 

did not conclude that there was a causal relationship, but rather that there may have been a number of 

coincident factors (one of which may have been active sonar) that ultimately resulted in the stranding 

event.” (Southall, 2006) 

4.1.5.2.16 Estimated Acoustic Effects on ESA Listed Species 

The endangered species that may occur within the area modeled for the Proposed Action include the 

North Pacific right whale (Eubalaena japonica), the humpback whale (Megaptera novaeangliae), the sei 



whale (Balaenoptera borealis), the fin whale (Balaenoptera physalus), the blue whale (Balaenoptera 

musculus), the sperm whale (Physeter macrocephalus), the Hawaiian monk seal (Monachus 

schauinslandi), the loggerhead sea turtle (Caretta caretta), the green sea turtle (Chelonia mydas), the 

hawksbill sea turtle (Eretmochelys imbricata), the leatherback sea turtle (Dermochelys coriacea), and the 

olive ridley sea turtle (Lepidochelys olivacea). 

Acoustic exposure model results indicate that no ESA listed species would be exposed to energy that 

could result in a PTS, or Level A harassment under the MMPA. The acoustic exposure model predicts 

that some ESA listed species may be exposed to acoustic energy that could result in TTS or behavioral 

modification. All harassment resulting from exposure to acoustic sources would be short term and 

temporary in nature. Under Alternative 1, the proposed USWEX would only occur for 3 to 4 days, up to 

six times per year, further reducing the potential to affect ESA listed species as a result of extended 

exposure. 

The RIMPAC 06 Biological Opinion (National Oceanic and Atmospheric Administration, 2006), which 

covers the same types of exercises and locations as USWEX, concluded that the proposed exercises may 

affect but are not likely to adversely affect Hawaiian monk seals, blue whales, and North Pacific right 

whales, and those species were not considered in greater detail within the Biological Opinion. The 

Biological Opinion went on to conclude that RIMPAC exercises would not be expected to appreciably 

reduce the sei, fin, and sperm whales’ likelihood of surviving and recovering in the wild. In addition, the 

Biological Opinion concluded that sea turtles exposed to mid-frequency active tactical sonar are not likely 

to respond to the exposure. The analysis and conclusions from the RIMPAC 06 Biological Opinion are 

considered in the analysis for USWEX. 

Pinnipeds 

Monk Seals—There are approximately 55 monk seals in the main Hawaiian Islands (U.S. Department of 

the Navy, Commander, U.S. Pacific Fleet, 2005). Since there are no density numbers for monk seals, the 

ratio of the monk seal Hawaiian stock (55) to the fin whale Hawaiian stock (174) or 55/174=32%, was 

used to calculate the acoustic exposure numbers. Based on input from NMFS, only the acoustic energy 

above 195 dB re 1 µPa 2 -s was evaluated for monk seals. The acoustic effects analysis predicts that 

USWEX training events would not result in the exposure of any monk seal to accumulated acoustic 

energy between 195 to < 215 dB re 1 µPa 2 -s. In addition, the majority of the sonar training events will 

take place in the deep ocean far offshore of the main islands, beyond the primary and secondary 

occurrence areas for monk seals. None of the proposed exercises are scheduled to occur in critical habitat 

of the Hawaiian monk seal which has been designated from shore to 20 fathoms in 10 areas of the 

northwestern Hawaiian Islands. Nor will any of the proposed activities affect the prey species of the 

Hawaiian monk seal. Thus, the proposed USWEX activities will not affect designated critical habitat for 

the Hawaiian monk seal. 

Based on limited available information, the hearing capabilities of endangered Hawaiian monk seals are 

most sensitive at 12 to 28 kHz. Below 8 kHz, their hearing is less sensitive than that of other pinnipeds. 

Because the mid-frequency active tactical sonar proposed for USWEX transmits at frequencies below 

hearing thresholds for Hawaiian monk seals, monk seals that are exposed to those transmissions are not 

likely to respond to that exposure. (National Oceanic and Atmospheric Administration, 2006) 



Consequently, any potential exposure to the mid-frequency active tactical sonar utilized in USWEX 

would not result in a disruption of natural monk seal behavioral patterns. The U.S. Navy concludes that 

the proposed USWEX activities would result in no effect to Hawaiian monk seals. 

Sea Turtles 

Five species of sea turtles could potentially occur within the USWEX ASW training areas. These species 

are the green turtle, loggerhead turtle, hawksbill turtle, leatherback turtle, and olive ridley turtle. All are 

protected under the ESA. Studies indicate that the auditory capabilities of sea turtles are centered in the 

low-frequency range (


whales exposed to 3.25 kHz to 8.4 kHz pulses interrupted their activities and left the area, other studies 

indicate that, after an initial disturbance, the marine mammals return to their previous activity. During 

playback experiments off the Canary Islands, André et al. (1997) reported that foraging whales exposed to 

a 10 kHz pulsed signal did not exhibit any general avoidance reactions. When resting at the surface in a 

compact group, sperm whales initially reacted strongly then ignored the signal completely (André et al., 

1997). In the RIMPAC Biological Opinion, NMFS concluded that additional evidence suggests that 

sperm whales are likely to detect mid-frequency sonar transmissions and in most circumstances, they are 

likely to try to avoid that exposure. Those sperm whales that do not avoid the sound field created by the 

mid-frequency sonar might interrupt communications, echolocation, or foraging behavior. In either case, 

sperm whales would experience significant disruptions of normal behavior patterns that are essential to 

their individual fitness. NMFS went on to state “Because of the relatively short duration of the acoustic 

transmissions associated with the proposed RIMPAC exercises, we do not, however, expect these 

disruptions to result in the death or injury of any individual marine mammal or to result in physiological 

stress responses that rise to the level of distress.” 

Considering these various studies, the U.S. Navy concludes that USWEX activities may affect sperm 

whales. 

Fin Whale—The abundance estimate of fin whales in the EEZ of the Hawaiian Islands is 174 (CV = 0.77) 

within only the offshore water habitat (density estimate of 0.0001/km 2 ). The acoustic effects analysis 

predicts that 6 USWEX training events could result approximately 48 exposures to accumulated acoustic 

energy in excess of 173 dB re 1 µPa 2 -s. No exposures are expected to accumulated acoustic energy in 

excess of 190 dB re 1 µPa 2 -s. 

It is likely that posted observers would detect fin whales at the surface given their large size (probability 

of trackline detection = 0.90; Barlow, 2003) and pronounced blow. In the rare event that fin whales are 

present in the proposed USWEX areas, any potential behavioral disturbance from exposure to hullmounted 

mid-frequency active tactical sonar would not be significant. Fin whales primarily produce low 

frequency calls (below 1 kHz) with source levels up to 186 dB re 1 µPa at 1 m, although it is possible 

they produce some sounds in the range of 1.5-28 kHz (review by Richardson et al., 1995). There are no 

audiograms of baleen whales, but they tend to react to anthropogenic sound below 1 kHz, suggesting that 

they are more sensitive to low frequency sounds (Richardson et al., 1995). In the St. Lawrence estuary 

area, fin whales avoided vessels with small changes in travel direction, speed and dive duration, and slow 

approaches by boats usually caused little response (MacFarlane, 1981). Fin whales continued to vocalize 

in the presence of boat noise (Edds and Macfarlane, 1987). Based on this information, any undetected fin 

whales transiting the proposed USWEX ASW training areas are not likely to respond when exposed to 

active acoustic energy. The exposure would not cause disruption of natural behavioral patterns to a point 

where such behavioral patterns would be abandoned or significantly altered. In addition, protective 

measures presented in Chapter 5 would reduce the potential for exposure. As such, USWEX activities 

may affect fin whales. 

Sei Whale—The abundance estimate of sei whales in the EEZ of the Hawaiian Islands is 77 (CV = 1.06) 

within the offshore water habitat. Since there are no density numbers for sei whales, the ratio of the sei 

whale Hawaiian stock (77) to the fin whale Hawaiian stock (174) was used to calculate the acoustic 

exposure numbers (77/174=44%). The acoustic effects analysis predicts that 6 USWEX training events 

could result in approximately 21 exposures to accumulated acoustic energy in excess of 173 dB re 

1 µPa 2 -s. No exposures are expected to accumulated acoustic energy above 190 dB re 1 µPa 2 -s. 



It is likely that posted observers would detect sei whales at the surface given their large size (probability 

of trackline detection = 0.90; Barlow 2003) and pronounced blow. In the rare event that sei whales are 

present in the proposed USWEX areas, any potential behavioral disturbance from exposure to hullmounted 

mid-frequency active tactical sonar would not be significant. There is little information on the 

acoustic abilities of sei whales or their response to human activities. The only recorded sounds of sei 

whales are frequency modulated sweeps in the range of 1.5-3.5 kHz (Thompson et al., 1979; Knowlton et 

al. 1991) but it is likely that they also vocalized at frequencies below 1 kHz as do fin whales. There are 

no audiograms of baleen whales but they tend to react to anthropogenic noise below 1 kHz suggesting 

that they are more sensitive to low frequency sounds (Richardson et al., 1995). Sei whales were more 

difficult to approach than were fin whales and moved away from boats but were less responsive when 

feeding (Gunther, 1949). Based on this limited information, even though any undetected sei whales 

transiting the proposed USWEX ASW training areas may exhibit a reaction when initially exposed to 

active acoustic energy, the effects would not cause disruption of natural behavioral patterns to a point 

where such behavioral patterns would be abandoned or significantly altered. In addition, protective 

measures presented in Chapter 5 would reduce the potential for exposure. As such, USWEX activities 

may affect sei whales. 

Humpback Whale—Humpback whales in Hawaiian waters are considered to be from the central North 

Pacific stock (Angliss and Lodge, 2004). There are an estimated 4,005 (CV = 0.095) individuals in this 

stock (Angliss and Lodge, 2004). Estimates from Mobley et al. (2001a), Calambokidis et al. (1997), and 

Baker and Herman (1981) suggest that the stock has increased in abundance. The acoustic effect analysis 

predicts that 6 USWEX training events could result in approximately 10,273 exposures to accumulated 

acoustic energy in excess of 173 dB re 1 µPa 2 -s, 472 exposures to accumulated acoustic energy in excess 

of 190 dB, and 49 exposures to accumulated acoustic energy between 195-


USWEX training events are conducted over a large area, with relatively fast moving sonar platforms and 

for a short period of 3 to 4 days, six times per year, but humpback whales do not inhabit the Hawaiian 

Islands area throughout the year. Humpback whales utilize Hawaiian waters as a major breeding ground 

during winter and spring (November through April). Peak abundance around the Hawaiian Islands is 

from late February through early April (Mobley et al., 2001a; Carretta et al., 2005). It is very likely, 

however, that lookouts would detect humpback whales at the surface given their large size (up to 16 m), 

surface behaviors (breaching or raising the flukes prior to diving), the very long and white patchy pectoral 

fins, and pronounced balloon shaped blow. In addition, protective measures presented in Chapter 5.0 

would reduce the potential for exposure to mid-frequency active tactical sonar. In addition to these 

standard measures, the U.S. Navy issues an annual message to all ships and aircraft operating in the 

Hawaii OPAREA during humpback whale calving season. Vessels are directed to not approach to within 

100 yards of a humpback whale, and aircraft are directed to not operate within 1,000 ft of a humpback 

whale (in accordance with 50 CFR 224.103(a)). Commanders are directed to ensure that their watch 

officers and pilots understand these requirements. 

Based on this information, USWEX training events may affect humpback whales. 

Consultation 

Based on the potential effects to endangered species described above, the U.S. Navy consulted with 

NMFS under Section 7 of the ESA and received a Biological Opinion and Incidental Take Statement. 

The resultant conclusion from the NMFS Biological Opinion is as follows: “After reviewing the current 

status of the endangered fin whale, humpback whale, sei whale, and sperm whale, the environmental 

baseline for the action area, the effects of the proposed Undersea Warfare Exercises, and the cumulative 

effects, it is NMFS’ biological opinion that the Navy’s proposed Undersea Warfare Exercises in waters 

off the State of Hawaii from January 2007 through January 2009 may adversely affect, but is not likely to 

jeopardize the continued existence of these threatened and endangered species under NMFS jurisdiction.” 

The Reasonable and Prudent Measures and Terms and Conditions required under the Incidental Take 

Statement (included in Section 5.1.4 of this EA/OEA) are identified to ensure Navy’s compliance under 

ESA during USWEX. 

4.1.5.3 Safety and Health—Ocean Area, Hawaiian Islands—ASMEX, ASWEX, 

GUNEX 

All PMRF- and FACSFAC Pearl Harbor-controlled fleet training activities that occur over the open water 

would continue to be conducted mainly in Warning Areas and Restricted Airspace. Range Safety 

officials ensure the safe operation of projectiles, targets, missiles, air operations, and other hazardous fleet 

training activity in controlled areas. The range safety procedures avoid risks to the public and operations. 

Before any operation is allowed to proceed, the over water target area is determined to be clear using 

inputs from ship sensors, visual surveillance of the range from aircraft and range safety boats, radar data, 

and acoustic. In addition, prior to conducting any training on PMRF, the operation must obtain PMRF 

safety approval before proceeding, covering the type of weapon, type of target, speed, altitude, debris 

corridor, and surface water hazard area (Pacific Missile Range Facility, Barking Sands, 1998). 

Since the target areas are cleared of personnel prior to any operations being conducted, the only public 

health and safety issue is if an operation exceeds the safety area boundaries. Risk to public health and 

safety is reduced by providing termination systems on some of the missiles and by determining that the 

target area—based on the distance the system can travel for those missiles without flight termination 



(typical air-to-air missile)—is clear. In the cases where a system does not have a flight termination, the 

target area is determined clear for unauthorized vessels and aircraft, based on the flight distance the 

vehicle can travel, plus an 8-kilometer (5-mile) area beyond the system performance parameters (Pacific 

Missile Range Facility, Barking Sands, 1998). 

In addition, all activities must be in compliance with DoD Directive 4540.1 and OPNAVINST 3770.4A, 

which specify procedures for conducting aircraft operations and for missile/projectile firing, namely the 

missile/projectile “firing areas shall be selected so that trajectories are clear of established oceanic air 

routes or areas of known surface or air activity.” 

Missile training exercises occur routinely during daylight hours within Restricted Area R-3101 and 

Warning Area W-188 under the control of PMRF. The DoD takes every reasonable precaution during the 

planning and execution of the operation of training exercises to prevent injury to human life and wildlife 

or damage to property. Specific safety plans are developed to ensure that each hazardous operation is in 

compliance with applicable policy and regulations and to ensure that the general public and range 

personnel and assets are provided an acceptable level of safety. For missile and weapons systems, PMRF 

Safety establishes criteria for the safe execution of the test operation in the form of Range Safety 

Approval and Range Safety Operational Plan documents, which are required for all weapon and target 

systems using the Warning Areas. These include the allowable launch and flight conditions and flight 

control methods to contain all the munitions and missile within the predetermined target areas, ordnance 

drop zones, and jettison areas that have been determined to be clear of nonessential personnel and aircraft 

(Pacific Missile Range Facility, Barking Sands, 1998). 

The impacts of training exercises on safety and health are not expected to be different for USWEX 

training than for routine training activities customarily conducted in open water training areas. 

4.1.5.4 Environmental Justice 

EO 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-Income 

Populations, was issued on 11 February 1994. Its objectives include development of federal agency 

implementation strategies, identification of minority and low-income populations where proposed federal 

actions have disproportionately high and adverse human health and environmental effects, and 

participation of minority and low-income populations. Although an Environmental Justice analysis is not 

mandated by NEPA, DoD has directed that NEPA will be used as the primary approach to implement the 

provision of the Executive Order. 

An environmental justice impact would be a long-term environmental, cultural, health, or economic effect 

that has a disproportionately high and adverse effect on a nearby minority or low-income population. 

Environmental Justice concerns could be triggered where the percentage of persons in low-income or 

minority populations in the census area meaningfully exceeds the percentage in the regions of 

comparison; the percentage of low-income or minority population in the census area exceeds 50 percent; 

and the proposed activities would result in substantial adverse effects to one or both of the above 

populations. No long-term, adverse environmental, cultural, health, or economic effects have been 

identified in this EA/OEA, and therefore there are no Environmental Justice impacts. 



4.2 ALTERNATIVE 2—CONDUCT FOUR USWEX PER YEAR 

Alternative 2 is a proposal designed to meet typical U.S. Navy and DoD current and near-term operational 

training requirements based on known and expected force structure. Generally, the CSGs prefer to 

conduct their USWEXs south of Oahu in order to take advantage of the geography and also to allow its 

embarked air wing to conduct training at PTA on the island of Hawaii. These areas are depicted in Figure 

2-1 as ASW Modeling Areas 4, 5, and 6. ESGs would conduct their USWEXs in ASW Modeling Areas 

1, 2, and 3. For analysis purposes it was assumed that two CSG USWEXs would occur between May and 

October, and one would occur between November and April. The single ESG would occur between May 

and October. Non-ASW activities would occur at PMRF, MCTAB, Kaula, and PTA. 

The potential impacts of USWEX activities at PMRF, MCTAB, Kaula, and PTA would be similar to 

those described for Alternative 1 in Sections 4.1.1, 4.1.2, 4.1.3, 4.1.4, and 4.1.5 except there would only 

be one ESG USWEX and therefore only one AMPHIBEX per year. In addition there would be one less 

CSG per year for a total of three. This would result in fewer activities at Kaula and PTA. 

The potential impacts of USWEX activities on the open ocean areas for Alternative 2 would be similar, 

but less than those described for Alternative 1. Impacts on Airspace (Section 4.1.5.1) and Safety and 

Health (Section 4.1.5.3) would be similar to those described for Alternative 1. Impacts on Biological 

Resources would be similar to those described in Section 4.1.5.2 except as discussed below. 

4.2.1 Estimated Acoustic Effects on Marine Mammals (MMPA) 

As described for Alternative 1, the model results, when adjusted to a realistic operational tempo, included 

no Level A harassment from the USWEX exercise. However, as described in Section 4.1.5.2.10, all 

predicted Level B exposure of beaked whales is treated as non-lethal Level A harassment. All Level B 

exposure would be short term and temporary in nature. In addition, the short-term non-injurious 

exposures predicted to cause TTS or temporary behavioral disruptions are considered Level B exposure in 

this EA even though it is highly unlikely that the disturbance would be to a point where behavioral 

patterns are abandoned or significantly altered. The proposed USWEX Exercise would only occur for 3 

to 4 days up to four times per year, further reducing the potential to affect marine mammals as a result of 

extended use over time. 

The modeling for USWEX 2006 analyzed the potential interaction of mid-frequency active tactical sonar 

with marine mammals that occur in the Hawaiian Islands Operating Area. The modeled exposure 

numbers by species and location are presented in Table 4-5 (173 dB sub-TTS threshold) and Table 4-6 

(190 dB threshold) and indicate the potential Level B exposures during four USWEX per year as defined 

for Alternative 2. There is no predicted MMPA Level A exposure, and so all numbers on the table 

represent Level B exposure. The table includes the number of estimated exposures for each species 

within each USWEX ASW acoustic model area. 



MARINE MAMMAL 

SPECIES 



USWEX ASW MODELING AREA 


1 2 3 4 5 6 

Sub 

TTS 

Total 

TOTALS 

Rough-toothed dolphin 101 95 91 733 79 843 1,942 29 

Dwarf sperm whale 78 72 68 554 62 666 1,500 9 

Fraser’s dolphin 72 66 63 533 57 610 1,402 15 

†Cuvier’s beaked whale 54 50 48 367 43 463 1,025 4 

Spotted dolphin 93 133 159 980 47 504 1,916 18 


Short-finned pilot whale 64 86 99 626 36 381 1,291 8 


*Sperm whale 33 32 31 215 26 286 623 2 



Spinner dolphin 65 112 141 798 23 242 1,381 12 


†Blainville’s beaked whale 10 10 11 75 8 82 196 1 

†Longman’s beaked whale 3 3 3 21 2 27 58 0 


Bryde’s whale 4 3 3 17 3 36 66 0 

Killer whale 3 2 2 18 2 22 48 1 

*Fin whale 2 2 2 8 2 18 33 0 


*Sei whale 1 1 1 1 4 1 8 14 0 

*Blue whale 0 0 0 0 0 0 0 0 

Minke whale 0 0 0 0 0 0 0 0 

*Humpback whale 0 0 0 2,856 0 0 2,856 14 

*Monk seal 1 0 0 0 0 0 0 0 0 

Sub-TTS (dB 173) Total 718 810 867 8,892 486 5,213 16,986 

TTS 

Total 

TTS Total 7 8 8 59 4 49 135 

Notes: 



1 




MARINE MAMMAL 

SPECIES 





1 2 3 4 5 6 

TOTALS PER 

YEAR 

Sub- 

TTS 

Total 

Rough-toothed dolphin 7 7 6 36 6 65 127 29 

Dwarf sperm whale 4 4 3 22 3 37 73 9 

Fraser’s dolphin 5 5 4 27 5 51 97 15 

†Cuvier’s beaked whale 2 2 2 12 2 17 36 4 

Spotted dolphin 7 10 11 58 3 31 120 18 


Short-finned pilot whale 4 5 6 33 2 21 72 8 


*Sperm whale 1 1 1 6 1 7 16 2 



Spinner dolphin 5 8 10 50 1 8 82 12 



whale 


whale 

TTS 

Total 

0 0 0 3 0 3 7 1 

0 0 0 1 0 1 2 0 


Bryde’s whale 0 0 0 0 0 0 1 0 

Killer whale 0 0 0 1 0 2 3 1 

*Fin whale 0 0 0 0 0 0 0 0 


*Sei whale 1 0 0 0 0 0 0 0 0 

*Blue whale 0 0 0 0 0 0 0 0 

Minke whale 0 0 0 0 0 0 0 0 

Humpback whale 0 0 0 123 0 0 123 14 

*Monk seal 1 0 0 0 0 0 0 0 0 

Sub-TTS (dB 190) Total 45 50 54 427 29 313 918 

TTS Total 7 8 8 59 4 49 135 

Notes: 



1 




Appendix B presents the results of the marine mammal acoustic effect modeling conducted for USWEX. 

As shown on Table 4-5, endangered species with potential Level B exposures (at 173 dB) are sperm 

whale, fin whale, sei whale, humpback whale, and monk seal. When a sub-TTS threshold of 190 dB is 

used as shown on Table 4-6, the endangered species with Level B exposures are sperm whales and 

humpback whales. Potential impacts to these species for Alternative 2 are discussed in Section 4.2.2. 

Since the density of sei whales is unknown, potential sei whale exposures were calculated using the 

modeled number of fin whale exposures and the ratio of sei whale Hawaiian stock to the fin whale 

Hawaiian stock, to approximate the number of sei whale exposures. 

Potential impacts on blue whales, North Pacific right whales, and minke whales would be unlikely, as 

described in Section 4.1.5.2.14. 

As described in Section 4.1.5.2.10, beaked whales are due special concern given that a stranding event in 

the Bahamas Islands in 2000 and a few other less documented events in other areas of the world suggest 

that beaked whales may be particularly susceptible to being affected by mid-frequency active tactical 

sonar. Since the exact causes of the beaked whale stranding events are unknown, separate, meaningful 

impact thresholds cannot be derived specifically for beaked whales. However, this EA takes a 

conservative approach and treats all behavioral disturbance of beaked whales as a potential non-lethal 

injury. All predicted Level B exposure of beaked whales is therefore counted as potential non-lethal 

Level A exposure. As shown in Table 4-6, there are three species of beaked whales present in the 

Hawaiian Islands that were modeled as potentially being exposed to sound levels resulting in potential 

Level B exposure. Cuvier’s beaked whales (173 dB n=1,025, 190 dB n=36), Blainville’s beaked whales 

(173 dB n=196, 190 dB n=7), and Longman’s beaked whales (173 dB n=58, 190 dB n=2) had the 

potential to be affected. These sound exposure numbers are conservatively accounted for as potential 

non-lethal Level A exposure. Based on operational characteristics and environmental conditions, it is not 

anticipated that the predicted exposure of beaked whales to USWEX acoustic sources would constitute 

serious injury or mortality. In addition, there have been numerous other ASW training events in the 

Hawaiian Islands Operating Area without stranding any beaked whale species. Thus the U.S. Navy 

concludes that the Proposed Action would not affect annual rates of recruitment or survival for beaked 

whales. 

When looking at the acoustic model results presented in Table 4-5 and Table 4-6, it is important to 

remember that although not considered in the modeling, the protective measures described in Chapter 5 

will reduce the likelihood of potential marine mammal exposures. U.S. Navy ships have a number of 

NMFS-approved procedures in place to detect marine mammals in their vicinity. U.S. Navy ships always 

have two, although usually more, personnel on watch serving as lookouts. In addition to the qualified 

Lookouts, the Bridge Team is present that at a minimum also includes an Officer of the Deck and one 

Junior Officer of the Deck whose responsibilities also include observing the waters in the vicinity of the 

ship. Other observers may include crews of airborne helicopters and P-3 aircraft who also observe the 

ocean surface for signs indicative of submarines. These aerial observers are required to report those 

observations to vessels engaged in the training events as part of the NMFS-approved procedures in place 

to detect marine mammals. 

It is the duty of the lookouts to report to the officer in charge, the presence of any object, disturbance, 

discoloration in the water (since they may be indicative of a submarine’s presence), or marine mammal 

within sight of the vessel. At night, personnel engaged in ASW training events may also employ the use 



of night vision goggles and infrared detectors, as appropriate that can also aid in the detection of marine 

mammals. Passive acoustic detection of vocalizing marine mammals is also used to alert bridge lookouts 

to the potential presence of marine mammals in the vicinity. Surface ships utilize a hydrophone that 

receives all sounds, such as marine mammal vocalizations, and transmit the sound to speakers located on 

the bridge and in the sonar station. When the mid-frequency sonar is not active, it is in receive mode and, 

in this passive mode, is continually monitored by the sonar operators. 

Consideration of negligible impact is required by NMFS to authorize incidental harassment of marine 

mammals. By definition, an activity has a “negligible impact” on a species or stock when it is determined 

that the total taking is not likely to reduce annual rates of adult survival or annual recruitment (i.e., 

offspring survival, birth rates). Additionally, the activity will not have an unmitigable adverse impact on 

the availability of such species or stock for taking for subsistence uses. The overall conclusion is that 

effects on marine mammal species or stocks from USWEX ASW training events would be negligible for 

the following reasons: 

• All acoustic exposures are within the non-injurious TTS or behavioral effects zone. 

• Although numbers presented in Table 4-5 and Table 4-6 represent estimated Level B exposures 

under the MMPA, as described above, application of conservative assumptions in the 

methodology likely results in an overestimated number of exposures by behavioral disturbance. 

Conservative methods include: Basing the effect thresholds on the total received EL is a 

conservative approach for treating multiple pings; in reality, some recovery will occur between 

pings and lessen the effect of a particular exposure; for purposes of the analysis, all surface ship 

sonars were modeled as equivalent to SQS-53, the U.S. Navy’s most powerful surface ship sonar, 

resulting in an overestimation of potential effects; and, sonar ping transmission durations were 

modeled as lasting 1 second per ping and omnidirectional when actual ping durations will be less 

than 1 second. 

• In addition, the model calculates exposures without taking into consideration standard protective 

measures, and is not indicative of a likelihood of either injury or harm. 

• Additionally, the protective measures described in Chapter 5 and required by the NDE under the 

MMPA signed by the Deputy Secretary of the Navy are designed to reduce sound exposure of 

marine mammals to levels below those that may cause “behavioral disruptions.” 

The U.S. Navy has coordinated with NMFS to establish protective measures identified in the NDE to 

obtain compliance with the MMPA. On January 23, 2007, the Deputy Secretary of Defense signed an 

NDE to exempt all military readiness activities that employ mid-frequency active sonar, either during 

major training exercises, or within established DoD maritime ranges or established operating areas, from 

compliance with the MMPA. This exemption covers activities for 2 years from the signing of the NDE. 

To adhere with the NDE, all exempt military readiness activities employing mid-frequency active sonar 

must follow required protective measures that were coordinated with NMFS. The NDE protective 

measures are included in the USWEX EA/OEA analysis (Section 5.1.2). 

4.2.2 Estimated Acoustic Effects on ESA Listed Species 

The endangered species that may occur in the geographic area for Alternative 2 include the North Pacific 

right whale (Eubalaena japonica), the humpback whale (Megaptera novaeangliae), the sei whale 

(Balaenoptera borealis), the fin whale (Balaenoptera physalus), the blue whale (Balaenoptera musculus), 



the sperm whale (Physeter macrocephalus), the Hawaiian monk seal (Monachus schauinslandi), the 

loggerhead sea turtle (Caretta caretta), the green sea turtle (Chelonia mydas), the hawksbill sea turtle 

(Eretmochelys imbricata), the leatherback sea turtle (Dermochelys coriacea), and the olive ridley sea 

turtle (Lepidochelys olivacea). 

The potential impacts to these species would be similar to that described under Alternative 1 except the 

exposure numbers are less under Alternative 2, as described below. As concluded for Alternative 1, 

proposed USWEX activities would result in no effect to Hawaiian monk seals, endangered sea turtles, 

blue whales, and North Pacific right whales. 

4.2.2.1 Cetaceans 

Sperm Whale—The abundance estimate of sperm whales in the EEZ of the Hawaiian Islands is 7,082 

(CV=0.30) (Barlow, 2003). Estimates from Calambokidis et al., (1997) and Baker and Herman (1987) 

suggest that the stock has increased in abundance. The acoustic effects analysis predicts that 4 USWEX 

training events could result in approximately 623 exposures to accumulated acoustic energy in excess of 

173 dB re 1 µPa 2 -s, 16 exposures to accumulated acoustic energy in excess of 190 dB re 1 µPa 2 -s, and 2 

exposures to accumulated acoustic energy between 195-


species under NMFS jurisdiction.” The Reasonable and Prudent Measures and Terms and Conditions 

required under the Incidental Take Statement (included in Section 5.1.4 of this EA/OEA) are identified to 

ensure the Navy’s compliance under ESA during USWEX. 

4.3 NO-ACTION ALTERNATIVE 

Under the No-Action Alternative, a USWEX would not occur; however, the individual training events 

that comprise a USWEX would continue to occur. Because the training events would not be coordinated 

into a USWEX, they would occur at other times throughout the year, not as part of CSG and ESG 

deployment training requirements. These individual exercises would continue to take place in the openocean, 

near shore, and onshore environments where they are routinely conducted. Therefore, the potential 

impacts of the No-Action Alternative would be similar to those described for the Proposed Action 

Alternatives. 

4.4 CUMULATIVE IMPACTS 

The regulations under 40 CFR § 1508.7 define cumulative impact as the “impact on the environment 

which results from the incremental impact of the action when added to other past, present, and reasonably 

foreseeable future actions regardless of what agency (federal or non-federal) or person undertakes such 

other actions. Cumulative impacts can result from individually minor but collectively significant actions 

taking place over a period of time.” 

4.4.1 Landside Cumulative Impacts 

The USWEX activities are short-term, intermittent, and do not involve land acquisition, new construction, 

or expansion of military presence in Hawaii. USWEX activities are proposed at existing military 

installations or designated impact areas. As such most of the past, present, and reasonably foreseeable 

future activities that could contribute to cumulative impacts are military activities at those locations. 

Table 4-7 presents the potential direct and indirect impacts at each location, other activities at those 

locations, and potential cumulative impacts for each resource area. 

As presented in Table 4-7, the amphibious landings proposed at PMRF and MCTAB could result in minor 

cumulative effects on biological resources. The proposed activities are not expected to result in 

cumulative effects on any of the other resource areas analyzed in this EA/OEA. The impacts from the 

proposed USWEX activities, when added to potential impacts from other past, present, and reasonably 

foreseeable future activities at the designated amphibious landing areas, would not result in significant 

cumulative impacts. 

Minor cumulative effects could occur on Biological Resources at the existing weapons impact areas 

proposed for USWEX on Kaula, and PTA as shown on Table 4-7. The impacts from the proposed 

USWEX activities, when added to potential impacts from other past, present, and reasonably foreseeable 

future activities at the designated impact areas, would not result in significant cumulative impacts. 



Table 4-7. USWEX Landside Cumulative Impacts Summary 

Location / Resource 

Pacific Missile Range 

Facility (PMRF), 

Kauai 

Marine Corps 

Training Area 

Bellows (MCTAB) 

Airspace-PMRF, Kauai 

Biological Resources- 

PMRF, Kauai 

Cultural Resources- 

PMRF, Kauai 

Safety and Health- 

PMRF, Kauai 

Airspace-MCTAB, 

Oahu 


MCTAB, Oahu 


MCTAB, Oahu 

Land Use-MCTAB, 

Oahu 

USWEX Direct & 

Indirect Impacts 

None - Coordination 

between FAA and 

Navy within Restricted 

airspace, limited rotary 

craft 

Vegetation trampled, 

noise, lights. No 

Threatened & 

Endangered species 

affected 

No sites affected, 

specific areas off limits 

None - Follow SOPs 



Navy, limited rotary 

craft 

Temporary impacts, 

limited to beach and 

existing trails. 

No sites affected, 

specific areas off limits 

Weekend use would 

close beach to the 

public 

Other Actions 

Past AMPHIBEX, 

Planned AMPHIBEX, 

Recreational Beach 

Use 




Use 




Use 




Use 




Use 




Use 




Use 




Use 

Potential Cumulative 

Impacts 

None - Coordination of 

USWEX and other 

actions airspace use 

during planning and 

during the exercise. 

Cumulative effects are 

not anticipated 

Minor additive 

impacts. No 

Threatened & 

Endangered species 

affected 

No USWEX impacts 

and other actions and 

impacts are similar. 















SOPs for USWEX and 

other actions require 

surveys, buffer zones, 

specific routes with 

keep-out areas. 

Potential impacts are 

short-term and 

temporary, with minor 

cumulative effects 






Weekend use expected 

to be minimal. Other 

actions and impacts are 

similar. Cumulative 

effects are not 

anticipated 



Table 4-7. USWEX Landside Cumulative Impacts Summary (Continued) 


Kaula 

Pohakuloa Training 

Area (PTA), Hawaii 

Noise-MCTAB, Oahu 

Airspace-Kaula 


Kaula 


Kaula 


Kaula 

Airspace-PTA, Hawaii 


PTA, Hawaii 



Elevated noise levels 

primarily limited to onbase 

areas 



Navy within Restricted 

airspace 

Ordnance impacts 

limited to less than 

10% of the island, 

birds startled, loss of a 

few individuals 

All cultural sites 

outside impact area 

Surface danger zone 

and restricted airspace 

provides safety for 

participants and the 

public 


between FAA, Navy, 

and PTA within 

Restricted and special 

use airspace 

Impact area is a 

degraded habitat, 

minimal impacts 

expected 

Other Actions 




Use 

Past & planned live 

fire gunnery & inert 

bombing exercises 










Past & planned DoD 

training - Army 

infantry, Stryker, live 

fire gunnery, close air 

support 





support 


Impacts 

Noise impacts would 

be short term and 

temporary. No 

overlapping exercises 

or cumulative noise 

effects. 








Minor additive impacts 

- potential loss of a few 

individuals during live 

fire gunnery exercises 

(less than 20 exercises 

per year) 


















INRMP used to 

manage and biological 

resources at PTA. 

USWEX activities 

provide minor addition 

to the quantity of 

ordnance from other 

actions within the 

impact area. 

Cumulative effects 

would be minimal 



Table 4-7. USWEX Landside Cumulative Impacts Summary (Continued) 



PTA, Hawaii 

Noise-PTA, Hawaii 


PTA, Hawaii 



Impact area not likely 

to contain intact 

cultural resources, not 

surveyed 

Short-term, temporary 

noise impacts from 

ordnance and aircraft 

overflights. 

Safety plans insure 

range personnel and 

the public are 

protected. Areas with 

contamination from 

munition by-products 

are limited to access by 

specially trained 

individuals. 

Other Actions 





support 





support 





support 


Impacts 


provide a minor 

addition to the quantity 

of ordnance from other 


impact area. Cultural 

resources have not 

been surveyed but 

there is a limited 

potential for cultural 

resources and a 

limited potential for 

cumulative effects 

Noise levels would be 

the same as similar 

ongoing exercises. 

The proposed action 

would not increase the 

number of exercises 

currently conducted at 

PTA and therefore 

cumulative effects are 



provide a minor 

addition to the quantity 

of ordnance from other 


impact area. Only 

specially trained 

individuals access the 

areas and therefore 

cumulative effects are 


4.4.2 Open Ocean Activities with Potential Marine Species Impacts 

The combination of potential impacts resulting from implementing the Proposed Action and other human 

activities or natural occurrences can affect marine species and their habitats. In general, it is assumed that 

events, such as earthquakes, major storms, the variable presence of prey species, and other natural forces 

acting on the marine environment, as well as disease processes, contamination, or biotoxins would be 

responsible for increases or decreases in the population and distribution of marine species on a much 

larger scale than the dispersed, infrequent, and intermittent activity associated with a USWEX event. 

However, information regarding the specific impacts these natural occurrences have on marine species is 

not readily available, and therefore their role in cumulative impacts is not known. Other past, present, 

and reasonably foreseeable future anthropogenic activities that occur within the Hawaiian Islands 

Operating area that could have a cumulative impact on marine species are presented in the following 

sections. 



In order to evaluate additive cumulative impact resulting from the potential effects of up to six USWEX 

training events in each 12-month period, it is necessary to place the predicted USWEX impact in 

perspective with other anthropogenic impacts on marine species. 

4.4.2.1 Commercial Fishing 

Bycatch is the term for the inadvertent capture of non-target species in fishing gear. Besides cetaceans 

and other marine mammals, sea turtles, seabirds and non-commercial fish species also are regularly 

caught and killed unintentionally as bycatch. The World Wildlife Fund convened a summit of the world’s 

leading cetacean experts in January 2002 in Annapolis, MD, which was attended by 25 scientists from six 

continents. The group reached consensus that the single biggest threat facing cetaceans worldwide is 

death as bycatch in fishing gear. More marine mammals die every year by getting entangled in fishing 

gear than from any other cause. Researchers estimated a global annual average of nearly 308,000 deaths 

per year—or nearly 1,000 per day (Read et. al., 2002). 

According to the NMFS Pacific Islands Region Marine Mammal Response Network Activity Update 

(dated January 2007), nine hooked or entangled marine mammals were encountered in Hawaii in 2006. 

From the fisheries observer program, to date, there have only been three observed interactions with ESA 

listed whale species and Hawaii-based pelagic longline fisheries. Two of the incidents involved 

humpback whales, and one involved a sperm whale. Recent Biological Opinions associated with the 

Fishery Management Program (FMP) have concluded that the region’s pelagic fisheries are not likely to 

have an adverse effect on the populations of the seven ESA listed whale species in the region. There are 

documented interactions with several non-ESA listed marine mammals as well although observer data 

from the Hawaii-based longline fishery show that interactions with non-ESA listed marine mammals are 

infrequent. At present, the Hawaii-based pelagic fisheries are classified as Category III fisheries under 

Section 118 of the MMPA; which defines them to have a remote likelihood or no known incidental take 

of marine mammals. (National Oceanic Atmospheric Administration Fisheries, 2004) The potential for 

cumulative impacts on marine mammals from commercial fishing are minimal. 

It should be noted that increases in ambient noise levels have the potential to mask an animal’s ability to 

detect objects, such as fishing gear and thus increase their susceptibility to bycatch. Mid-frequency active 

sonar transmission, however, involves a very small portion of the frequency spectrum and falls between 

the central hearing range of the (generally) low frequency specializing baleen whales and the (generally) 

high frequency specializing odontocetes. In addition, the active portion of mid-frequency active sonar is 

intermittent, brief, and individual units engaged in the exercise are separated by large distances. As a 

result, mid-frequency active sonar use during USWEX will not increase anthropogenic oceanic noise to 

any a reasonably foreseeable level of significance resulting in increased fishery interactions. 

4.4.2.2 Ship Strikes 

Ship strikes, or ship collisions with whales, are a recognized source of whale mortality worldwide. Of the 

11 species known to be hit by ships, the most frequently reported is the fin whale. Whale-watching tours 

are becoming increasingly popular, and ship strikes have risen in recent years. In the Hawaiian Islands, 

ship strikes of the humpback whale are of particular concern. According to the NMFS Pacific Islands 

Region Marine Mammal Response Network Activity Update (dated January 2007), there were nine 

reported collisions with humpback whales in 2006. Whale watching could also have an effect on whales 

by distracting them, displacing them from rich food patches, or by dispersing food patches with wake or 

propeller wash (Katona and Kraus, 1999). 



A review of recent reports on ship strikes provides some insight regarding the types of whales, locations 

and vessels involved, but also reveals significant gaps in the data. The Large Whale Ship Strike Database 

provides a summary of the 292 worldwide confirmed or possible whale/ship collisions from 1975 through 

2002 (Jensen and Silber, 2003). The report notes that the database represents a minimum number of 

collisions, because the vast majority probably goes undetected or unreported. In contrast, U.S. Navy 

vessels are likely to detect any strike that does occur, and they are required to report all ship strikes 

involving marine mammals. Overall, the percentages of U.S. Navy traffic relative to overall large 

shipping traffic are very small (on the order of 2%). 

All types of ships can hit whales, and much of the time the marine mammal is either seen too late, not 

observed until the collision occurs, or not detected. The ability of a ship to avoid a collision and to detect 

a collision depends on a variety of factors, including environmental conditions, ship design, size, and 

manning. 

Note that the majority of ships participating in a USWEX, such as U.S. Navy destroyers , have a number 

of advantages for avoiding ship strike as compared to most commercial merchant vessels. 

• The U.S. Navy ships have their bridges positioned forward, offering good visibility ahead of 

the bow. 

• Crew size is much larger than merchant ships 

• There are dedicated lookouts posted during a USWEX scanning the ocean for anything 

detectible in the water; anything detected is reported to the Officer of the Deck. 

• Navy lookouts receive extensive training including Marine Species Awareness Training 

designed to provide marine species detection cues and information necessary to detect marine 

mammals and sea turtles. 

• Navy ships are generally much more maneuverable than commercial merchant vessels. 

NOAA continues to review all shipping activities and their relationship to cumulative effects, in particular 

on large whale species. According to the NOAA report, the factors that contribute to ship strikes of 

whales are not clear, nor is it understood why some species appear more vulnerable than others. 

Nonetheless, the number of known ship strikes indicate that deaths and injuries from ships and shipping 

activities remain a threat to endangered large whale species. 

In July 2007, the State of Hawaii intends to start to run a high-speed ferry between the islands of Oahu, 

Maui, and Kauai. The ferry will run in designated close-to-shore water lanes. The project falls within the 

window of “reasonably foreseeable” future projects; however, given the location of the ferry water lanes, 

it is not anticipated that the increased vessel traffic from this commuting vessel will contribute to the 

cumulative effects when assessed in combination with the actions proposed in this EA/OEA. 

4.4.2.3 Anthropogenic Oceanic Noise 

The potential cumulative impact issue associated with mid-frequency active sonar use during USWEX is 

the addition of underwater sound to oceanic ambient noise levels, which in turn could have impacts on 

marine animals. Anthropogenic sources of ambient noise that are most likely to have contributed to 

increases in ambient noise are vessel noise from commercial shipping and general vessel traffic, 

oceanographic research, and naval and other use of sonar. 



The potential impact that USWEX events may have on the overall oceanic ambient noise level are 

reviewed in the following contexts: 

• Anthropogenic contributors to ambient sound levels in the world’s oceans; 

• Nominal unclassified operational parameters of the mid-frequency active sonar used during 

USWEX including proposed mitigation; 

• The contribution of such use of mid-frequency active sonar to oceanic noise levels relative to 

other human-generated sources of oceanic noise; and cumulative impacts and synergistic 

effects. 

4.4.2.3.1 Anthropogenic Contributors to Oceanic Noise Levels 

Ambient noise is environmental background noise. It is generally described as unwanted sound—sound 

that clutters and masks other sounds of interest (Richardson et al., 1995). Any potential for cumulative 

impact should be put into the context of recent changes to ambient sound levels in the world’s oceans as a 

result of anthropogenic activities. It should be noted, however, that there is a large and variable natural 

component to the ambient noise level as a result of events such as earthquakes, rainfall, waves breaking, 

and lightning hitting the ocean as well as biological noises such as those from snapping shrimp and the 

vocalizations of marine mammals. 

Andrew et al. (2002) compared ocean ambient sound from the 1960s with the 1990s for a receiver off the 

California coast. The data showed an increase in ambient noise of approximately 10 dB in the frequency 

range of 20 to 80 Hz and 200 and 300 Hz, and about 3 dB at 100 Hz over a 33-year period. A possible 

explanation for the rise in ambient noise is the increase in shipping noise. The most energetic regularlyoperated 

sound sources are seismic air gun arrays from approximately 90 vessels with typically 12 to 48 

individual guns per array, firing about every 10 seconds (Hildebrand, 2004). There are approximately 

11,000 supertankers worldwide, each operating 300 days per year, producing constant broadband noise at 

source levels of 198 dB (Hildebrand, 2004). 

Commercial Shipping 

The Final Report of the NOAA International Symposium on “Shipping Noise and Marine Mammals: A 

Forum for Science, Management, and Technology” stated that the worldwide commercial fleet has grown 

from approximately 30,000 vessels in 1950 to over 85,000 vessels in 1998 (National Research Council, 

2003; Southall, 2005). Between 1950 and 1998, the U.S. flagged fleet declined from approximately 

25,000 to less than 15,000 and currently represents only a small portion of the world fleet. Foreign 

waterborne trade in the United States has increased from 718 to 1,164 million gross metric tons from 

1981 to 2001. From 1985 to 1999, world seaborne trade doubled to 5 billion tons and currently includes 

90 percent of the total world trade, with container shipping movements representing the largest volume of 

seaborne trade. It is unknown how international shipping volumes and densities will continue to grow. 

However, current statistics support the prediction that the international shipping fleet will continue to 

grow at the current rate or at greater rates in the future. Shipping densities in specific areas and trends in 

routing and vessel design are as significant (or possibly more significant) than the total number of vessels. 

Densities along existing coastal routes are expected to increase both domestically and internationally. 

New routes are also expected to develop as new ports are opened and existing ports are expanded. Vessel 



propulsion systems are also advancing toward faster ships operating in higher sea states for lower 

operating costs; and container ships are expected to become larger along certain routes (Southall, 2005). 

Increases in ambient noise levels have the potential to mask a marine species’ ability to detect 

approaching vessels, thus increasing their susceptibility to ship strikes. As discussed previously, because 

mid-frequency active sonar transmissions are brief and intermittent, cumulative impacts from ship strikes 

due to masking from mid-frequency active sonar signals are not a reasonably foreseeable significant 

adverse impact on marine animals. 

Vessel Noise Sources 

Boats and ships produce sound due to propeller cavitation (or propeller singing) as well as other 

machinery. Propeller singing has a frequency between 100 and 1,000 Hz (Richardson et al., 1995). Noise 

from propulsion machinery enters the water through the hull of the ship. Propulsion machinery sources 

include rotating shafts, gear reduction transmissions, reciprocating parts, gear teeth, fluid flow turbulence, 

and mechanical friction. Other sources of noise include fathometers, pumps, non-propulsion engines, 

generators, ventilators, compressors, flow noise from water dragging on the hull, and bubbles breaking in 

the wake. Medium and large vessels generate frequencies up to approximately 50 Hz, primarily from 

propeller blade rate and secondarily from the engine cylinder firing rates and shaft rotation (Richardson et 

al., 1995). Propeller cavitation and flow noise can produce frequencies as high as 100 kHz but generally 

peak energy occurs between 50 and 150 Hz; and auxiliary machinery (pumps and compressors) may 

produce frequencies up to several kilohertz (Richardson et al., 1995). Moreover, most (83 percent) of the 

acoustic field surrounding large vessels is the result of propeller cavitation (Southall, 2005). Larger ships 

generally are diesel-powered and have two propellers, which are larger and slower rotating. These 

propellers typically have four blades, which turn at a rate of approximately 160 rpm and have a frequency 

of 10 to 11 Hz (Richardson et al., 1995). It is generally believed that acoustic source levels are not a 

function of speed for modern diesel vessels across most of their common operations (Heitmeyer et al., 

2004). Supply ships often have bow thrusters to help maneuver the ship. A bow thruster may create a 

harmonic tone with a high fundamental frequency, depending on the rotation rate of the thrusters. One 

study found nine harmonics, extending up to 1,064 Hz. In another study, the noise increased by 11 dB 

when the bow thrusters began operating. 

Small boats with large outboard engines produce source levels of 175 dB at frequencies up to several 

hundred hertz (Richardson et al., 1995; Erbe, 2002). A study was conducted on the effects of boat noise 

from whale-watching vessels on the interaction of humpback whales (Au and Green, 2000). Two boats 

were inflatables with outboard engines. Two were larger coastal boats with twin inboard diesel engines, 

and the fifth boat was a small water plane area twin hull (SWATH) ship. The study concluded that it is 

unlikely that the levels of sounds produced by the boats in the study would have any serious effect on the 

auditory system of humpback whales. Another study was conducted on the effects of boat noise from 

whale-watching vessels on pods of killer whales. The average number of whale-watching vessels around 

the whales has increased approximately fivefold from 1990 to 2000. This study found no significant 

difference in the duration of primary calls as a function of the presence and absence of boats during 1977 

to 1981 and 1989 to 1992, but there was a significant increase in call duration for all three pods studied in 

the presence of boats from 2001 to 2003 (Foot et al., 2004). 

A study was also conducted on the effects of watercraft noise on the acoustic behavior of bottlenose 

dolphins in Florida (Buckstaff, 2004). The study focused on short-term changes in whistle frequency 

range, duration, and rate of production. The frequency range and duration of signature whistles did not 



significantly change due to approaching vessels. However, dolphins whistled more often at the onset of 

approaching vessels compared to during and after vessel approaches. The whistle rate also increased 

more at the onset of a vessel approach than when there were no vessels present. 

In addition to mechanical noise, almost all vessels at sea are equipped with active sonar used as 

fathometers. Many vessels engaged in commercial or recreational fishing also use active sonar 

commonly referred to as “fish-finders.” Both types of sonar tend to be higher in frequency and lower in 

power as compared to the hull mounted mid-frequency active sonar used during USWEX; however, there 

are many more of these sonars, and they are in use much more often than Navy sonars. 

Undersea Research 

While oil and gas exploration, the main component of research taking place elsewhere, is not conducted 

in the Hawaiian Islands, undersea research using active sound sources does occur. Sound sources 

employed include powerful multibeam and sidescan sonars that are generally used for mapping the ocean 

floor and include both mid-frequency and high frequency systems. During research surveys, these sonars 

are run continuously, sweeping the ocean floor to accurately chart the complex bathymetry present over 

large areas of interest. 

4.4.2.3.2 Operational Parameters of the Navy Mid-Frequency Active Sonar 

As discussed in Section 2.2.1, the Navy’s most powerful surface ship sonar is the SQS-53, which has the 

nominal source level of 235 decibels (dB) re 1 µPa 2 -s @ 1 m. Generally (based on water conditions) a 

ping will lose approximately 60 dB after traveling 1,000 yards from the sonar dome, resulting in a 

received level of 175 dB at 1,000 yards from the sonar dome. The Navy’s standard mitigation measures 

consider the area within 1,000 yards of the bow (the sonar dome) a Safety Zone (see Section 5.1.2). The 

resulting 175 dB sound level at 1,000 yards, where the Navy’s mitigation Safety Zone begins, is for 

comparison, less than source level produced by the vocalization of many marine mammals and less than 

other sounds marine mammals may be exposed to, such as humpback fluke and flipper slaps at source 

levels of 183 to 192 dB (Richardson et al., 1995). 

The Navy’s standard mitigation measures are designed to prevent direct injury to marine mammals as a 

result of the sonar’s acoustic energy. If any detected marine mammal comes within 1,000 yards of the 

bow, the sonar power is reduced by 75% (6 dB). The average level (195 dB) at which the onset of 

measurable physiological change (e.g., TTS) could be experimentally determined occurs approximately 

220 yards from a sonar dome transmitting a one second 235 dB ping. The Safety Zone distance of 1,000 

yards is more than four times the average distance at which the onset of a measurable and temporary 

physiological change occurs, and yet a significant power reduction is mandated if a marine mammal 

comes within this range. Additional measures, detailed in Section 5.1.2 involving exercise planning, 

further the potential for there to be cumulative impacts or synergistic effect from the use of sonar during 

training exercises. 

A nominal sonar ping is approximately 1 second in duration followed by period of silence lasting 30 

seconds or longer during which the mid-frequency active sonar system listens for a return reflection of 

that ping. A USWEX event can last for 72 to 96 hours, although the ASW portion of the exercise may be 

much shorter. Within the ASW event where hull-mounted mid-frequency active sonar is used, the sonar 

system produces sound in the water only a small fraction of the time ASW is being conducted, or as in the 

preceding example, 2 seconds of sound every minute. When compared against naturally occurring and 



other man-made sources of noise in the oceans, the sonar pings during USWEX are only a brief and 

intermittent portion of the total acoustic noise. 

The SQS-53 sonar transmits at center frequencies of 2.6 kHz and 3.3 kHz. Details concerning the tactical 

use of specific frequencies are classified; however, the sonar ping used covers a very small portion of the 

frequency spectrum. Because of this, any masking would also only be restricted to this same small 

frequency span. As noted previously, the frequency spectrum used by mid-frequency active sonar 

generally falls between the central hearing range of the (generally) low frequency specializing baleen 

whales and the (generally) high frequency specializing odontocetes. 

Therefore, because the active portion of mid-frequency active sonar is intermittent, brief, and individual 

units engaged in the exercise are separated by large distances, mid-frequency active sonar use during 

USWEX will not increase anthropogenic oceanic noise to any a reasonably foreseeable level of 

significance resulting in increased fishery interactions. 

Cumulative Impacts and Synergistic Effects 

Mid-frequency active sonar uses a distinct and narrow fraction of the mid-frequency sound spectrum as 

noted previously (center frequencies of 2.6 kHz and 3.3 kHz). Other Navy systems are specifically 

designed to avoid use of these frequencies, which would otherwise interfere with the mid-frequency 

active sonar system. There should, therefore, be no cumulative impacts from multiple systems using the 

same frequency. For the same reason, there should be no synergistic effects from the systems in 

operation during USWEX. In addition, the probability that sound waves emanating from the sonar and 

having different ray paths could, in the far-field, combine in an additive synergistic manner at the precise 

point where a marine mammal was located is so very unlikely that it can be considered impossible. 

4.4.2.4 Environmental Contamination and Biotoxins 

Insufficient information is available to determine how, or at what levels and in what combinations, 

environmental contaminants may affect cetaceans (Marine Mammal Commission, 2003). There is 

growing evidence that high contaminant burdens are associated with several physiological abnormalities, 

including skeletal deformations, developmental effects, reproductive and immunological disorders, and 

hormonal alterations (Reijnders and Aguilar, 2002). It is possible that anthropogenic chemical 

contaminants initially cause immunosuppression, rendering whales susceptible to opportunistic bacterial, 

viral, and parasitic infection (De Swart et al., 1995). Specific information regarding the potential effects 

of environmental contamination on marine species in the Hawaiian Islands is not available, and therefore 

cumulative effects cannot be determined. Even events of large magnitude such as the 48 million gallon 

raw sewage spill in March 2006 into the ocean off Waikiki have had no apparent consequences. 

4.4.2.5 Other U.S. Navy Training Activities in the Open Ocean 

Currently the U.S. Navy conducts other Navy training activities at sea that have the potential to cause 

incremental acoustic effects to marine mammals. These activities are discussed below. 

Mine Warfare Exercise (MINEX) 

During these exercises, mine neutralization vehicles will be used to neutralize mine shapes on the sea 

floor or in the water column. This neutralization is accomplished with an underwater detonation of 



ordnance using mine neutralization systems containing net explosive weights of up to 20 pounds. MINEX 

training exercises are conducted at established locations near Oahu. 

Mitigation measures have been designed and implemented for MINEXs to minimize any potential 

adverse impacts to marine mammals and to avoid any significant or long-term adverse impacts to marine 

mammals and the coastal, cultural, or marine environment. As such the potential for cumulative impacts 

with the proposed USWEX activities would be minimal. 

Sinking Exercise of Surface Targets (SINKEX) 

A SINKEX is defined as the use of a vessel as a target or test platform against which live ordnance is 

fired. The purpose of a SINKEX is to train personnel, test weapons, and study the survivability of ship 

structures. The result is the eventual sinking of the vessel. SINKEX operations differ from ship shock 

trials in that the warheads used in a SINKEX are significantly smaller. The environmental considerations 

of a SINKEX are associated with the weapons used. The exact amount of ordnance and the type of 

weapon used in a SINKEX is situational and training-need dependent. 

The SINKEX target is a ship remediated to standards set by the U.S. Environmental Protection Agency. 

The U.S. Environmental Protection Agency grants the Department of the Navy a general permit through 

the Marine Protection, Research, and Sanctuaries Act to transport vessels “for the purpose of sinking such 

vessels in ocean waters…” (40 CFR Part 229.2) Subparagraph (a)(3) of this regulation states “All such 

vessel sinkings shall be conducted in water at least 1,000 fathoms (6,000 feet) deep and at least 50 

nautical miles from land.” 

Mitigation measures have been designed and implemented for SINKEX’s in order to minimize any 

potential adverse impacts to marine mammals and to avoid any significant or long-term adverse impacts 

to marine mammals and the coastal, cultural, or marine environment. As such, the potential for 

cumulative impacts with the proposed USWEX activities would be minimal. 

Other Hawaiian Islands Operating Area ASW Training 

The U.S. Navy is implementing a comprehensive strategy to support training with mid-frequency active 

tactical sonar in a manner protective of marine mammals. Protective measures are currently implemented 

to reduce the potential for sound exposure of marine mammals during training with mid-frequency active 

tactical sonar. 

The RIMPAC exercise includes extensive ASW and other training that is similar to that proposed for 

USWEX. RIMPAC occurs once every 2 years, and a separate USWEX would not be conducted during 

the same time period as RIMPAC. There would therefore be no overlap of activities between USWEX 

and RIMPAC, minimizing the potential for cumulative impacts. 

4.4.3 Summary of Marine Mammal Cumulative Impacts 

The new methodology applied for analyzing the potential effects of mid-frequency active tactical sonar 

from selected USWEX training events determined there is a potential for Level B harassment of marine 

mammals. As described in Section 4.1.5.2.1, Level B harassment is defined as a temporary threshold 

shift or a temporary behavioral disruption. As described above in Sections 4.1.5.2 and 4.2.1, the USWEX 



ASW training events are not likely to affect the species or stock through effects on annual rates of 

recruitment or survival, and the effects on marine mammal species or stocks would be insignificant. 

It is possible that harassment in any form may cause a stress response (Fair and Becker, 2000). Cetaceans 

can exhibit some of the same stress symptoms as found in terrestrial mammals (Curry, 1999). 

Disturbance from ship traffic, noise from ships, aircraft, and/or exposure to biotoxins and anthropogenic 

contaminants may stress marine mammals, weakening their immune systems, making them more 

vulnerable to parasites and diseases that normally would not be fatal. It is possible that the temporary, 

Level B exposures from USWEX activities, when combined with the other activities described in Section 

4.4.2, could result in a minimal incremental contribution to stress on marine mammals which could be 

considered a minor cumulative impact on marine mammals. 

In considering the insignificant impacts of the USWEX ASW training together with the minor impacts for 

the other activities described in the preceding Section 4.4.2, the U.S. Navy concludes there would be no 

significant cumulative impacts on marine mammals and the open ocean environment. 


5.0 Protective Measures 

5.0 PROTECTIVE MEASURES 

5.1 PROTECTIVE MEASURES RELATED TO ACOUSTIC EFFECTS 

Effective training in the proposed USWEX ASW areas dictates that ship, submarine, and aircraft 

participants utilize their sensors and exercise weapons to their optimum capabilities as required by the 

mission. The U.S. Navy recognizes that such use has the potential to cause behavioral disruption of some 

marine mammal species in the vicinity of an exercise (as outlined in Chapter 4). This chapter presents the 

U.S. Navy’s protective measures, outlining steps that would be implemented to protect marine mammals 

and federally listed species during USWEX training events. It should be noted that these protective 

measures have been standard operating procedures for unit level ASW training since 2004 and were 

implemented for previous USWEX-type exercises; their implementation during USWEX will not be new. 

This chapter also presents a discussion of other measures that have been considered and rejected because 

they are either: (1) not feasible; (2) present a safety concern; (3) provide no known or ambiguous 

protective benefit; or (4) have an unacceptable impact on training fidelity. 

5.1.1 Evolution of the Current Mitigation Measures 

The Navy’s current mitigation measures reflect the use of the best available science balanced with the 

NMFS precautionary approach and the requirements of the Navy to train. The current mitigation 

measures in use during the period of the current MMPA NDE (NDE II) were developed in coordination 

and with the approval of NMFS. To understand the development of these mitigation measures, it is 

necessary to review the process of review and analysis of effectiveness arising out of the MMPA 

Incidental Harassment Authorization (IHA) that was sought by the Navy for RIMPAC 2006. 

The 2006 RIMPAC IHA was issued on June 27, 2006, and it set forth mitigation measures regarding 

personnel training, use of aviation units to look for marine mammals, use of sonar personnel using 

passive indicators to check for marine mammals, limits on the sonar levels (generally), coastal exclusion 

zones, exclusion areas, safety zones, restrictions associated with “choke-points”, surface ducting 

conditions and low visibility, stranding response and reporting protocols. Most of the measures, 

especially the ones later determined to be most effective, were already Navy standard operating 

procedure. 

Three days after issuance of the IHA (on June 30, 2006), the Deputy Secretary of Defense issued a 

National Defense Exemption (NDE I) under the MMPA exempting all military readiness activities 

employing mid-frequency active sonar during RIMPAC 2006 and during all other major exercises or 

onboard established DoD maritime ranges or established operating areas for a 6 month period from the 

compliance requirements of MMPA. In doing so, however, the Deputy Secretary of Defense required 

RIMPAC 2006 activities to adhere to the 2006 RIMPAC IHA. 

Because the RIMPAC 2006 IHA was the first authorization issued by NMFS for mid-frequency active 

sonar use, the mitigation measures required by NMFS in the IHA were purposefully inclusive of all 

potential mitigation measures without knowledge of either their effectiveness or impact on training 

fidelity. The IHA recognized the uncertainty associated with the effectiveness of the mandated mitigation 

measures and therefore required that a report be generated after RIMPAC 2006 that would provide “An 



assessment of the effectiveness of the mitigation and monitoring measures with recommendations on how 

to improve them.” 

This assessment was provided to NMFS as the RIMPAC After-Action Report in April 2007 and consisted 

of a review of compiled data from operators involved in the exercise, exercise reconstructions, and details 

of marine mammal detections by exercise participants, shore-based observers, and an aerial marine 

mammal survey (see Appendix C). Analyzing the mitigation measures, the report concluded that certain 

measures in the IHA should be removed from future consideration because they proved unfeasible, 

presented a safety concern, provided no known or unambiguous protective benefit (having no basis in 

scientific fact), and/or because they impacted the effectiveness of the required training. 

Review of the 2006 RIMPAC After-Action Report and discussions with NMFS, resulted in twenty-nine 

mitigation measures, which incorporated and refined the measures set forth in the 2006 RIMPAC IHA 

and NDE I, and were then adopted for the current NDE (NDE II) with concurrence from NMFS and the 

Department of Commerce on 23 January 2007. All of the mandatory mitigation measures contained 

within NDE II are in the USWEX EA/OEA and have been utilized in the USWEXs conducted since 

January 2007 (see Section 5.1.4). 

5.1.2 Alternative Mitigation Measures Considered but Eliminated 

The Navy has continued to revise mitigation measures based on the best available scientific data, the 

Navy’s training requirements, and evolving regulations. The Navy has previously analyzed and 

eliminated from further consideration several mitigation measures, many of which were suggested during 

the public comment period. Some of these eliminated measures have been recently adopted by other 

nations when using mid-frequency active sonar. Some of these foreign nations’ measures (such as 

predictive modeling) are not applicable to Hawaii given the lack of information upon which to base any 

modeling. The remainder of the foreign nations’ measures impact the effectiveness of ASW training to 

an unacceptable degree. Several, for example require safety zones that assume the ability of 

watchstanders to sight marine mammals at distances that, in reality, they cannot. These increased 

distances also greatly increase the area that must be monitored. If a safety zone increases from 1,000 

yards to 4,000 yards, the area that must be monitored increases sixteenfold, making the larger safety zone 

operationally infeasible. Some foreign mitigation measures require that sonar levels at particular 

distances from ships be attenuated to a level that significantly negates training for U.S. sailors. 

Potential U.S. mitigation measures were assessed based on supporting science, their likely effectiveness 

in avoiding harm to marine mammals, the extent to which they would adversely impact military readiness 

activities, including personnel safety, and the practicality of implementation, and impact on the 

effectiveness of the military readiness activity. Alternative mitigation measures considered previously 

but rejected by the Navy for the reasons cited above included: 

• Using non-Navy personnel onboard Navy vessels to provide surveillance of ASW or other 

exercise events. 

– Security clearance issues would have to be overcome to allow non-Navy observers 

onboard exercise participants. 

– Use of non-Navy observers is not necessary given that Navy lookouts are extensively 

trained in spotting items at or near the water surface. Navy lookouts receive more hours 



of training, and utilize their skills more frequently, than many third party trained marine 

mammal observers. 

– Use of Navy lookouts is the most effective means to ensure quick and effective 

communication within the command structure and facilitate implementation of mitigation 

measures if marine species are spotted. A critical skill set of effective Navy training is 

communication. Navy lookouts are trained to act swiftly and decisively to ensure that 

information is passed to the appropriate supervisory personnel. 

– The Navy and NMFS have not developed the necessary lengthy and detailed procedures 

that would be required to facilitate the integration of information from non-Navy 

observers into the command structure. 

– Some training events will span one or more 24-hour period with operations underway 

continuously in that timeframe. It is not feasible to maintain non-Navy surveillance of 

these operations given the number of non-Navy observers that would be required onboard 

for the minimally required, three 8-hour shifts. 

– Surface ships having mid-frequency active sonar have limited berthing capacity. 

Exercise planning includes careful consideration of this limited capacity in the placement 

of exercise controllers, data collection personnel, and Afloat Training Group personnel 

on ships involved in the exercise. Inclusion of non-Navy observers onboard these ships 

would require that, in some cases, there would be no additional berthing space for 

essential Navy personnel required to fully evaluate and efficiently use the training 

opportunity to accomplish the exercise objectives. 

• Visual monitoring or surveillance using non-Navy observers from non-military aircraft or 

vessels to survey before, during, and after exercise events. 

– Use of non-Navy observers in the air or on civilian vessels compromises security due to 

the requirement to provide advance notification of specific times/locations of Navy 

platforms (this information is Classified). 

– The areas where training events will mainly occur (the representative areas modeled) 

cover approximately 170,000 square nautical miles within the HRC. Contiguous ASW 

events may cover many hundreds of square miles in a few hours given the participants 

are usually not intervisible (separated by many tens of miles) and are constantly in 

motion. The number of civilian ships and/or aircraft required to monitor the area around 

these events would be considerable (in excess of a thousand of square miles). It is, thus, 

not feasible to survey or monitor the large exercise areas in the time required to ensure 

these areas are devoid of marine mammals. In addition, marine mammals may move into 

or out of an area, if surveyed before an event, or an animal could move into an area after 

an exercise took place. Given that there are no adequate controls to account for these or 

other possibilities and there are no identified research objectives, there is no utility to 

performing either a before or an after-the-event survey of an exercise area. 

– Survey during an event raises safety issues with multiple, slow civilian aircraft operating 

in the same airspace as military aircraft engaged in combat training activities. In 

addition, most of the training events take place far from land, limiting both the time 

available for civilian aircraft to be in the exercise area and presenting a concern should 

aircraft mechanical problems arise. 

– Scheduling civilian vessels or aircraft to coincide with training events would impact 

training effectiveness since exercise event timetables cannot be precisely fixed and are 

instead based on the free-flow development of tactical situations. Waiting for civilian 



aircraft or vessels to complete surveys, refuel, or be on station would slow the unceasing 

progress of the exercise and impact the effectiveness of the military readiness activity. 

– The vast majority of HRC training events involve a Navy aerial asset with crews 

specifically training to detect objects in the water. The capability of sighting from both 

surface and aerial platforms provides excellent survey capabilities using the Navy’s 

existing exercise assets. 

• Seasonal, problematic complex/steep bathymetry or habitat avoidance. 

– The habitat requirements for most of the marine mammals in the Hawaiian Islands are 

unknown. Accordingly, there is no information available on possible alternative exercise 

locations or environmental factors that would otherwise be less important to marine 

mammals in the Hawaiian Islands. In addition, exercise locations were very carefully 

chosen by exercise planners based on training requirements and the ability of ships and 

submarines to operate safely. Moving the exercise events to alternative locations would 

impact the effectiveness of the training and has no known benefit (especially as there is 

no scientific data available to determine which specific areas should be avoided). 

Seemingly straightforward mitigation measures such as “avoiding sea-mounts” fail to 

recognize that there are over 300 seamounts in the HRC (making it impossible to avoid 

them all and still conduct USWEX), fail to define scientific parameters for seamounts 

critical to marine mammals (such as a critical depth from the surface), and fail to define 

what would constitute a buffer that would “avoid” these areas. Similar simplistic “steep 

bathymetry” avoidance suggestions fail to define parameters and fail to recognize that all 

the islands in the Hawaiian chain rise from the ocean floor in a steep bathymetric rise. 

Finally, “seasonal” avoidance suggestions fail to take into account the fact that the 

mitigation measures avoid all detected marine mammals no matter the season. In 

addition, the Navy specifically informs all naval vessels to increase vigilance when the 

first humpback whales have been sighted around the Hawaiian Islands. The purported 

need for such suggested mitigation measures is based on speculative findings from other 

areas of the world that do not have direct application to the unique environment present 

in Hawaii. Such measures also can not be accurately implemented until there is a 

scientific basis defining parameters for the measures. Lacking any scientific basis behind 

the measures in Hawaii and lacking any evidence in Hawaii that there has ever been an 

impact resulting from the lack of these measures, there is no evidence that they would 

increase the protection of marine mammals. However, they would unacceptably impact 

the effectiveness of the training. 

• Avoid active sonar use within 12 nm from shore or 25 km from the 200-m isobath. 

– This measure was made part of the RIMPAC 2006 authorization by NMFS and was 

based on the assumption that avoidance of the North American continental shelf was a 

prudent mitigation measure given the presence of beaked whales in the Gulf of Mexico. 

NMFS modified the measure (a 200-m isobath replacing the continental shelf criteria) for 

Hawaii because they had received a public comment during rulemaking for a proposed 

action taking place elsewhere. This measure lacks any scientific basis when applied to 

conditions in Hawaii. 

– There is no scientific basis for requiring this mitigation measure in the Pacific and no 

known basis for the specific metrics (25 km of the 200 m isobath). 

– During RIMPAC 2006, this mitigation measure precluded active ASW training in the 

littoral region, which significantly impacted realism and training effectiveness. 



– This procedure had no observable effect on the protection of marine mammals during 

RIMPAC 2006 and its value is unclear (there is a lengthy history of sonar use in the 

Hawaiian Islands without any strandings or apparent effect on marine mammals). 

However, its effect on realistic training is significant. 

• Using active sonar with output levels as low as possible consistent with mission requirements 

and use of active sonar only when necessary. 

– Operators of sonar equipment are always cognizant of the environmental variables 

affecting sound propagation. In this regard the sonar equipment power levels are always 

set consistent with mission requirements. 

– Active sonar is only used when required by the mission since it has the potential to alert 

opposing forces to the sonar platform’s presence. Passive sonar and all other sensors are 

used in concert with active sonar to the maximum extent practical when available and 

when required by the mission. 

• Suspending the exercise at night, periods of low visibility and in high sea-states when marine 

mammals are not readily visible. 

– It is imperative that the Navy be able to operate at night, in periods of low visibility, and 

in high sea-states using the full potential of sonar as a sensor. The Navy must train as 

expected to fight, and adopting this prohibition would eliminate this critical military 

readiness requirement. 

• Strong surface duct: 

– The Navy must train in the same manner as it will fight. As described above, the 

complexity of ASW requires the most realistic training possible for the effectiveness and 

safety of the sailors. Reducing power in strong surface duct conditions would not 

provide this training realism because the unit would be operating differently than it would 

in a combat scenario, reducing training effectiveness and the crew’s ability. Additionally 

and most importantly, water conditions in the exercise areas on the time and distance 

scale necessary to implement this measure are not uniform and can change over the 

period of a few hours as effects of environmental conditions such as wind, sunlight, cloud 

cover, and tide changes alter surface duct conditions. In fact, this mitigation measure 

could not be accurately and uniformly employed during RIMPAC 2006. The exercise 

headquarters found so many variations in water conditions across the exercise area that 

the determination of “strong surfacing ducting” was futile. The result is continually 

changing mitigation requirements that can not be accurately implemented and would 

force personnel to attempt implementing a measure based on a poorly defined and 

ephemeral environmental condition, instead of focusing on the training. 

– There is no scientific evidence that this mitigation measure is effective or that it provides 

additional protection for marine mammals than the protection provided through “safety 

zones”. 

• Scaling down the exercise to meet core aims. 

– Training exercises are always constrained by the availability of funding, resources, 

personnel, and equipment with the result being they are always scaled down to meet only 

the core requirements. 

• Limiting the active sonar event locations. 

– Areas where events are scheduled to occur are carefully chosen to provide for the safety 

of operations and to allow for the realistic tactical development of the exercise scenario. 



Otherwise limiting the exercise to a few areas would adversely impact the effectiveness 

of the training. 

– Limiting the exercise areas would concentrate all sonar use, resulting in unnecessarily 

prolonged and intensive sound levels vice the more transient exposures predicted by the 

current planning that makes use of multiple exercise areas. 

• Passive Acoustic Monitoring. 

– As noted in the preceding section, passive detection capabilities are used to the maximum 

extent practicable consistent with the mission requirements to alert exercise participants 

to the presence of marine mammals in an event location. 

• Using ramp-up to attempt to clear an area prior to the conduct of exercises. 

– Ramp-up procedures involving slowly increasing the sound in the water to necessary 

levels have been utilized in other non-DoD activities. Ramp-up procedures are not a 

viable alternative for training exercises, as the ramp-up would alert opponents to the 

participants’ presence and not allow the Navy to train realistically, thus adversely 

impacting the effectiveness of the military readiness activity. 

– The implicit assumption is that animals would have an avoidance response to the low 

power sonar and would move away from the sound and exercise area; however, there is 

no data to indicate this assumption is correct. Given there is no data to indicate that this 

is even minimally effective and because ramp-up would have an impact on the 

effectiveness of the military readiness activity, it was eliminated from further 

consideration. 

• Vessel speed reduction. 

– Vessels engaged in training use extreme caution and operate at a slow, safe speed 

consistent with mission and safety. Ships and submarines need to be able to react to 

changing tactical situations in training as they would in actual combat. Placing arbitrary 

speed restrictions would not allow them to properly react to these situations. Training 

differently than what would be needed in an actual combat scenario would decrease 

training effectiveness and reduce the crew’s abilities. 

• Reporting marine mammal sightings to augment scientific data collection. 

– Ships, submarines, aircraft, and personnel engaged in training events are intensively 

employed throughout the duration of the exercise. Their primary duty is accomplishment 

of the exercise goals, and they should not be burdened with additional duties, unrelated to 

that task. Any additional workload assigned that is unrelated to their primary duty would 

adversely impact the effectiveness of the military readiness activity they are undertaking. 

• Use of new technology (e.g., unmanned reconnaissance aircraft, underwater gliders, 

instrumented ranges) to enhance monitoring of marine animals. 

– Although the Navy does work with many new technologies, they remain unproven, very 

expensive, and limited in availability. The Navy has been investigating data collected by 

the underwater instrumented range at PMRF to collect passive acoustic data on marine 

mammals. 

• Use of larger and more protective shut down zones 

The current power down and shut down zones are based on modeling of the source output 

level, propagation, and transmission characteristics of sonar. 



• Choke-points. 

– The choke-point mitigation measure required in RIMPAC 2006 could not be precisely 

implemented (lacking biological criteria defining the measure related to this tactical 

event), significantly impacted military readiness, had no scientific basis for 

implementation in the Hawaiian Islands, and provided no observable protection to marine 

mammals. Restricting Navy operations in choke-points limits the ability to train 

realistically in the known diesel submarine threat environment and directly impacts a 

vital military readiness activity. 

– As a practical matter, the Navy will conduct no more than three “choke-point” exercises 

in USWEX. These exercises will occur in the Kaulakahi Channel (between Kauai and 

Niihau) and the Alenuihaha Channel (between Maui and Hawaii). These exercises fall 

outside of the requirements listed in NDE I/RIMPAC 2006 to avoid canyon-lie areas and 

to operate sonar farther than 25 km from the 200m isobath. 

5.1.3 Current Exercise Mitigation Measures 

5.1.3.1 Personnel Training 

U.S. Navy shipboard lookout(s) are highly qualified and experienced observers of the marine 

environment. Their duties require that they report all objects sighted in the water to the Officer of the 

Deck (e.g., trash, a periscope, a marine mammal) and all disturbances (e.g., surface disturbance, 

discoloration) that may be indicative of a threat to the vessel and its crew. There are personnel serving as 

lookouts on station at all times (day and night) when a ship or surfaced submarine is moving through the 

water. 

U.S. Navy lookouts undergo extensive training in order to qualify as a watchstander. This training 

includes on-the-job instruction under the supervision of an experienced watchstander, followed by 

completion of the Personal Qualification Standard program, certifying that they have demonstrated the 

necessary skills (such as detection and reporting of partially submerged objects). In addition to these 

requirements, many Fleet lookouts periodically undergo a 2-day refresher training course. 

The U.S. Navy includes marine species awareness as part of its training for its bridge lookout personnel 

on ships and submarines. Marine species awareness training was updated in 2005, and the additional 

training materials are now included as required training for U.S. Navy lookouts. This training addresses 

the lookout’s role in environmental protection, laws governing the protection of marine species, U.S. 

Navy stewardship commitments, and general observation information to aid in avoiding interactions with 

marine species. Marine species awareness and training is reemphasized by the following means: 

• Bridge personnel on ships and submarines—Personnel utilize marine species awareness 

training techniques as standard operating procedure, they have available the “whale wheel” 

identification aid when marine mammals are sighted, and they receive updates to the current 

marine species awareness training as appropriate. 



• Aviation units—All pilots and aircrew personnel, whose airborne duties during ASW operations 

include searching for submarine periscopes, report the presence of marine species in the vicinity 

of exercise participants. 

• Sonar personnel on ships, submarines, and ASW aircraft—Both passive and active sonar 

operators on ships, submarines, and aircraft utilize protective measures relative to their platform. 

The Letter of Instruction for each USWEX mandates specific actions to be taken if a marine 

mammal is detected, and these actions are standard operating procedure throughout the exercise. 

Implementation of these protective measures is a requirement and involves the chain of command with 

supervision of the activities and consequences for failing to follow orders. Activities undertaken on a 

U.S. Navy vessel or aircraft are highly controlled. Very few actions are undertaken on a U.S. Navy vessel 

or aircraft without oversight by and knowledge of the chain of command. Failure to follow the orders of 

one’s superior in the chain of command can result in disciplinary action. 

5.1.4 NDE II Protective Measures for Major Exercises (Jan 2007- Jan 2009) 

As noted previously, on 23 January 2007, the Deputy Secretary of Defense issued NDE II exempting all 

military readiness activities that employ mid-frequency active sonar during major training exercises or 

within established DoD maritime ranges or established operating areas from the permitting requirements 

of MMPA. This exemption covers activities for 2 years from the signing of NDE II. To adhere with 

NDE II, all exempt military readiness activities employing mid-frequency active sonar must follow the 

required mitigation measures introduced in Section 5.1.2 and detailed below. 

I. General Maritime Protective Measures: Personnel Training: 

1. All lookouts onboard platforms involved in ASW training events will review the NMFS approved 

Marine Species Awareness Training (MSAT) material prior to mid-frequency active sonar use. 

2. All Commanding Officers, Executive Officers, and officers standing watch on the Bridge will 

have reviewed the MSAT material prior to a training event employing the use of mid-frequency 

active sonar. 

3. U.S. Navy lookouts will undertake extensive training in order to qualify as a watchstander in 

accordance with the Lookout Training Handbook (NAVEDTRA 12968-B). 

4. Lookout training will include on-the-job instruction under the supervision of a qualified, 

experienced watchstander. Following successful completion of this supervised training period, 

Lookouts will complete the Personal Qualification Standard program, certifying that they have 

demonstrated the necessary skills (such as detection and reporting of partially submerged 

objects). This does not preclude personnel being trained as lookouts from being counted as those 

listed in previous measures so long as supervisors monitor their progress and performance. 

5. Lookouts will be trained in the most effective means to ensure quick and effective 

communication within the command structure in order to facilitate implementation of protective 

measures if marine species are spotted. 



II. General Maritime Protective Measures: Lookout and Watchstander Responsibilities: 

6. On the bridge of surface ships, there will always be at least three people on watch whose duties 

include observing the water surface around the vessel. 

7. In addition to the three personnel on watch noted previously, all surface ships participating in 

ASW exercises will have at all times during the exercise at least two additional personnel on 

watch as lookouts. 

8. Personnel on lookout and officers on watch on the bridge will have at least one set of binoculars 

available for each person to aid in the detection of marine mammals. 

9. On surface vessels equipped with mid-frequency active sonar, pedestal mounted “Big Eye” 

(20x110) binoculars will be present and in good working order to assist in the detection of marine 

mammals in the vicinity of the vessel. 

10. Personnel on lookout will employ visual search procedures employing a scanning methodology in 

accordance with the Lookout Training Handbook (NAVEDTRA 12968-B). 

11. After sunset and prior to sunrise, lookouts will employ Night Lookouts Techniques in accordance 

with the Lookout Training Handbook. 

12. Personnel on lookout will be responsible for reporting all objects or anomalies sighted in the 

water (regardless of the distance from the vessel) to the Officer of the Deck, since any object or 

disturbance (e.g., trash, periscope, surface disturbance, discoloration) in the water may be 

indicative of a threat to the vessel and its crew or indicative of a marine species that may need to 

be avoided as warranted. 

III. Operating Procedures 

13. A Letter of Instruction, Mitigation Measures Message or Environmental Annex to the Operational 

Order will be issued prior to the exercise to further disseminate the personnel training 

requirement and general marine mammal protective measures. 

14. Commanding Officers will make use of marine species detection cues and information to limit 

interaction with marine species to the maximum extent possible consistent with safety of the ship. 

15. All personnel engaged in passive acoustic sonar operation (including aircraft, surface ships, or 

submarines) will monitor for marine mammal vocalizations and report the detection of any 

marine mammal to the appropriate watch station for dissemination and appropriate action. 

16. During mid-frequency active sonar operations, personnel will utilize all available sensor and 

optical systems (such as night vision goggles) to aid in the detection of marine mammals. 

17. U.S. Navy aircraft participating in exercises at sea will conduct and maintain, when operationally 

feasible and safe, surveillance for marine species of concern as long as it does not violate safety 



constraints or interfere with the accomplishment of primary operational duties. 

18. Aircraft with deployed sonobuoys will use only the passive capability of sonobuoys when marine 

mammals are detected within 200 yards of the sonobuoy. 

19. Marine mammal detections will be immediately reported to assigned Aircraft Control Unit for 

further dissemination to ships in the vicinity of the marine species as appropriate where it is 

reasonable to conclude that the course of the ship will likely result in a closing of the distance to 

the detected marine mammal. 

20. Safety Zones—When marine mammals are detected by any means (aircraft, shipboard lookout, or 

acoustically) within 1,000 yards of the sonar dome (the bow), the ship or submarine will limit 

active transmission levels to at least 6 dB below normal operating levels. 

(i) Ships and submarines will continue to limit maximum transmission levels by this 6-dB factor 

until the marine mammal has been seen to leave the area, has not been detected for 30 minutes, or 

the vessel has transited more than 2,000 yards beyond the location of the last detection. 

(ii) Should a marine mammal be detected within or closing to inside 500 yards of the sonar dome, 

active sonar transmissions will be limited to at least 10 dB below the equipment's normal 

operating level. Ships and submarines will continue to limit maximum ping levels by this 10-dB 

factor until the marine mammal has been seen to leave the area, has not been detected for 30 

minutes, or the vessel has transited more than 2,000 yards beyond the location of the last 

detection. 

(iii) Should the marine mammal be detected within or closing to inside 200 yards of the sonar 

dome, active sonar transmissions will cease. Sonar will not resume until the animal has been seen 

to leave the area, has not been detected for 30 minutes, or the vessel has transited more than 2,000 

yards beyond the location of the last detection. 

(iv) Special conditions applicable for dolphins and porpoises only: If, after conducting an initial 

maneuver to avoid close quarters with dolphins or porpoises, the Officer of the Deck concludes 

that dolphins or porpoises are deliberately closing to ride the vessel's bow wave, no further 

mitigation actions are necessary while the dolphins or porpoises continue to exhibit bow wave 

riding behavior. 

(v) If the need for power-down should arise as detailed in “Safety Zones” above, the ship or 

submarine shall follow the requirements as though they were operating at 235 dB - the normal 

operating level (i.e., the first power-down will be to 229 dB, regardless of at what level above 235 

sonar was being operated). 

21. Prior to start up or restart of active sonar, operators will check that the Safety Zone radius around 

the sound source is clear of marine mammals. 



22. Sonar levels (generally)—the ship or submarine will operate sonar at the lowest practicable level, 

not to exceed 235 dB, except as required to meet tactical training objectives. 

23. Helicopters shall observe/survey the vicinity of an ASW exercise for 10 minutes before the first 

deployment of active (dipping) sonar in the water. 

24. Helicopters shall not dip their sonar within 200 yards of a marine mammal and shall cease 

pinging if a marine mammal closes within 200 yards after pinging has begun. 

25. Submarine sonar operators will review detection indicators of close-aboard marine mammals 

prior to the commencement of ASW operations involving active mid-frequency sonar. 

26. Increased vigilance during major ASW training exercises with tactical active sonar when critical 

conditions are present. 

Based on lessons learned from strandings in the Bahamas (2000), Madeira (2000), the Canaries 

(2002), and Spain (2006), beaked whales are of particular concern since they have been 

associated with mid-frequency active sonar operations. The U.S. Navy should avoid planning 

major ASW training exercises with mid-frequency active sonar in areas where they will 

encounter conditions that, in their aggregate, may contribute to a marine mammal stranding event. 

The conditions to be considered during exercise planning include: 

(i) 

Areas of at least 1000 m depth near a shoreline where there is a rapid change in 

bathymetry on the order of 1,000-6,000 meters occurring across a relatively short 

horizontal distance (e.g., 5 nm). 

(ii) 

(iii) 

Cases for which multiple ships or submarines (≥ 3) operating mid-frequency active sonar 

in the same area over extended periods of time (≥ 6 hours) in close proximity (≤ 10 nm 

apart). 

An area surrounded by land masses, separated by less than 35 nm and at least 10 nm in 

length, or an embayment, wherein operations involving multiple ships/subs (≥ 3) 

employing mid-frequency active sonar near land may produce sound directed toward the 

channel or embayment that may cut off the lines of egress for marine mammals. 

(iv) Although not as dominant a condition as bathymetric features, the historical presence of a 

strong surface duct (i.e., a mixed layer of constant water temperature extending from the sea 

surface to 100 or more feet). 

If the major exercise must occur in an area where the above conditions exist in their aggregate, 

these conditions must be fully analyzed in environmental planning documentation. The U.S. 

Navy will increase vigilance by undertaking the following additional protective measure: 

A dedicated aircraft (U.S. Navy asset or contracted aircraft) will undertake 

reconnaissance of the embayment or channel ahead of the exercise participants to detect 

marine mammals that may be in the area exposed to active sonar. Where practical, 



advance survey should occur within about 2 hours prior to mid-frequency active sonar 

use, and periodic surveillance should continue for the duration of the exercise. Any 

unusual conditions (e.g., presence of sensitive species, groups of species milling out of 

habitat, any stranded animals) shall be reported to the Officer in Tactical Command, who 

should give consideration to delaying, suspending, or altering the exercise. 

All safety zone power down requirements described in Measure 20 apply. 

The post-exercise report must include specific reference to any event conducted in areas 

where the above conditions exist, with exact location and time/duration of the event, and 

noting results of surveys conducted. 

IV. Coordination and Reporting 

27. The U.S. Navy will coordinate with the local NMFS Stranding Coordinator for any unusual 

marine mammal behavior and any stranding, beached live or dead cetacean(s) or floating marine 

mammals that may occur at any time during or within 24 hours after completion of midfrequency 

active sonar use associated with ASW training activities. 

28. The U.S. Navy will submit a report to the Office of Protected Resources, NMFS, within 120 days 

of the completion of a Major Exercise. This report must contain a discussion of the nature of the 

effects, if observed, based on both modeled results of real-time events and sightings of marine 

mammals. 

29. If a stranding occurs during an ASW exercise, NMFS and the U.S. Navy will coordinate to 

determine if mid-frequency active sonar should be temporarily discontinued while the facts 

surrounding the stranding are collected. 

5.1.5 Conservation Measures 

The U.S. Navy will continue to fund ongoing marine mammal research in the Hawaiian Islands. Results 

of conservation efforts by the U.S. Navy in other locations will also be used to support efforts in the 

Hawaiian Islands. The U.S. Navy is coordinating long-term monitoring/studies of marine mammals on 

various established ranges and operating areas: 

• Coordinating with NMFS to conduct surveys within the selected Hawaiian Islands Operating 

Area as part of a baseline monitoring program. 

• Implementing a long-term monitoring program of marine mammal populations in the Hawaiian 

Islands Operating Area, including evaluation of trends. 

• Continuing U.S. Navy research and U.S. Navy contribution to university/external research to 

improve the state of the science regarding marine species biology and acoustic effects. 

• Sharing data with NMFS and via the literature for research and development efforts. 

The U.S. Navy has contracted with a consortium of researchers from Duke University, University of 

North Carolina at Wilmington, University of St. Andrews, and the NMFS Northeast Fisheries Science 

Center to conduct a pilot study analysis and develop a survey and monitoring plan that lays out the 

recommended approach for surveys (aerial/shipboard, frequency, spatial extent, etc.) and data analysis 



(standard line-transect, spatial modeling, etc.) necessary to establish a baseline of protected species 

distribution and abundance and monitor for changes that might be attributed to ASW operations on the 

Atlantic Fleet Undersea Warfare Training Range. The Research Design for the project will be utilized in 

evaluating the potential for implementing similar programs in the Hawaiian Islands ASW operations 

areas. In addition, a similar research and monitoring project has been initiated in the Hawaiian Islands 

and the remainder of the Pacific Fleet Operating Areas. 

5.1.6 ESA Prudent Mitigation Measures, Terms and Conditions 

As part of the ESA consultation process, NMFS provided the following Reasonable and Prudent 

Measures and Terms and Conditions within the Endangered Species Act Section 7 Biological Opinion 

and Incidental Take Statement for USWEX. As presented in the Biological Opinion, the measures 

described below, which are non-discretionary, must be implemented by the U.S. Navy in order for the 

exemption in section 7(o)(2) to apply. If the U.S. Navy fails to adhere to the terms and conditions of the 

Incidental Take Statement, the protective coverage of section 7(o)(2) may lapse. 

Reasonable and Prudent Measures 

The National Marine Fisheries Service believes the following reasonable and prudent measures are 

necessary and appropriate to minimize the impacts of incidental take on threatened and endangered 

species: 

1. The U.S. Navy shall implement measures to reduce the probability of exposing fin whales, 

humpback whales, sei whales, and sperm whales to mid-frequency sonar transmissions that will 

occur during each of the different Undersea Warfare Exercises conducted between January 2007 

and January 2009. 

2. The U.S. Navy shall implement a monitoring program that allows the Navy and NMFS to 

evaluate the assumptions contained in this biological opinion and that underlie this incidental 

take statement. 

3. The Navy shall submit a report that evaluates its mitigation measures and reports the results of its 

monitoring program. 

Terms and Conditions 

In order to be exempt from the prohibitions of section 9 of the Endangered Species Act of 1973, as 

amended, the U.S. Navy must comply with the following terms and conditions, which implement the 

reasonable and prudent measures described above and outline reporting and monitoring requirements, as 

required by the section 7 regulations (50 CFR 402.14(i)) 

1. The U.S. Navy shall implement measures to reduce the probability of exposing fin whales, 

humpback whales, sei whales, and sperm whales to mid-frequency sonar transmissions that will 

occur during each of the different Undersea Warfare Exercises conducted between January 2007 

and January 2009. 

2. If the U.S. Navy cannot avoid exposing fin whales, humpback whales, sei whales, and sperm 

whales to mid-frequency sonar transmissions that will occur during each of the different 

Undersea Warfare Exercises conducted between January 2007 and January 2009, the U.S. Navy 

shall develop and implement measures that reduce the probability of exposing fin whales, 

humpback whales, sei whales, and sperm whales to mid-frequency sonar transmissions at 



received levels that would be expected to elicit behavioral or other responses that are assumed to 

be adverse to these whales. 

3. By 31 March 2007, the U.S. Navy shall develop a monitoring program whose study design 

provides a method to estimate 

a. the number of fin whales, humpback whales, sei whales, and sperm whales that are 

exposed to mid-frequency sonar at received levels equal to or greater than 173 dB and 

190 dB during any of the four to six Undersea Warfare Exercises conducted annually 

between January 2007 and January 2009; 

b. the behavioral or other observable responses of any of these whales that are exposed to 

mid-frequency sonar at these received levels; 

c. the effectiveness of the Navy’s entire suite of mitigation measures at avoiding exposing 

any of these whales to mid-frequency sonar; and 

d. the effectiveness of the different measures contained in the Navy’s suite of mitigation 

measures at avoiding exposing any of these whales to mid-frequency sonar. 

4. Within 15 business days of completing an exercise, the Navy shall provide the Chief, Endangered 

Species Division, Office of Protected Resources with a verbal briefing that summarizes the 

starting and ending dates of the exercise, initial counts of the number of the different marine 

mammal species that were observed within 2,000 yards of a vessel that had been transmitting 

mid-frequency active sonar, and the initial estimated distance between those mammals and the 

transmitting vessel. 

5. Within 120 calendar days of completing an exercise, the U.S. Navy shall provide a the Chief, 

Endangered Species Division, Office of Protected Resources (with a copy provided to the 

Assistant Regional Administrator for Protected Resources in NMFS’ Pacific Islands Regional 

Office [PIRO]) with a written report that shall include the following information: 

a. a summary of the exercise (the starting and ending date of the exercise, the number of 

ships and aircraft involved in the exercise, and the number of hours passive and active 

sonar was used during the exercise); 

b. the specific mitigation measures the Navy implemented during the exercise; 

c. the number of fin whales, humpback whales, sei whales, and sperm whales that (i) had 

been detected within 500, 1,000, and 2,000 yards of a sonar dome during an active 

transmission and (ii) the Navy’s estimate of the number of fin whales, humpback whales, 

sei whales, and sperm whales that had been exposed to mid-frequency sonar at received 

levels equal to or greater than 173 dB and 190 dB; 

d. the reports of the activity or activities that fin whales, humpback whales, sei whales, and 

sperm whales had been observed to exhibit while they were within 500, 1,000, and 2,000 

yards of a sonar dome that were actively transmitting during the exercise (for example, a 

report should not identify ‘playing”; it should identify the behavior that allowed the 

observer to conclude the animal was “playing”). 



Reports of an observation shall identify the date, time, and visual conditions associated 

(for example, if the observation is produced from a helicopter, the report should identify 

the speed, vector, and altitude of the airship; the sea state, and lighting conditions) with 

the observation; and how long an observer or set of observers maintained visual contact 

with a marine mammal; 

e. an evaluation of the effectiveness of those mitigation measures at avoiding exposing 

endangered whales to ship traffic and mid-frequency sonar. This evaluation shall identify 

the specific observations that support any conclusion the Navy reaches about the 

effectiveness of the mitigation measures; 

f. an evaluation of the monitoring program’s ability to detect whales that occur within 500, 

1,000, and 2,000 yards of a sonar dome during an active transmission (or close enough to 

an exercise to be exposed to mid-frequency sonar at received levels equal to or greater 

than 173 dB) with the specific evidence that supports any conclusion the Navy reaches. 

6. The Navy shall continue to coordinate with NMFS on the "Communications and Response 

Protocol for Stranded Marine Mammal Events During Navy Operations in the Pacific Islands 

Region" that is currently under preparation by NMFS PIRO to facilitate communication during 

USWEX. The Navy will coordinate with the NMFS Stranding Coordinator for any unusual 

marine mammal behavior, including stranding, beached live or dead cetacean(s), floating marine 

mammals, or out-of-habitat/milling live cetaceans that may occur at any time during or shortly 

after USWEX activities. After USWEX, NMFS and the Navy will prepare a coordinated report 

on the practicality and effectiveness of the protocol that will be provided to Navy/NMFS 

leadership. 

Conservation Recommendations 

The following conservation recommendations would provide information for future consultations 

involving the issuance of marine mammal permits that may affect endangered whales as well as reduce 

harassment related to research activities: 

1. Cumulative Impact Analysis. The U.S. Navy should work with NMFS Endangered Species 

Division and other relevant stakeholders (the Marine Mammal Commission, International 

Whaling Commission, and the marine mammal research community) to develop a method for 

assessing the cumulative effects of anthropogenic noise on cetaceans, pinnipeds, sea turtles, and 

other marine animals. This includes the cumulative impacts on the distribution, abundance, and 

the physiological, behavioral and social ecology of these species. 

In order to keep NMFS Endangered Species Division informed of actions minimizing or avoiding adverse 

effects or benefiting listed species or their habitats, the Permits, Conservation and Education Division of 

the Office of Protected Resources should notify the Endangered Species Division of any conservation 

recommendations they implement in their final action. 



5.1.7 USWEX After-Action Reports 

Under the terms and conditions of the Biological Opinion, Navy is required to provide a report that 

evaluates the mitigation measures and details results from the Navy’s exercise monitoring program. 

Additionally, the NDE measure #28 requires the Navy to submit a report that includes discussion of the 

nature of the effects, if observed, based on modeling results and marine mammal sightings. Accordingly, 

the Navy has prepared a single After-Action report for the only USWEX exercises (both conducted in 

April, 2007), fulfilling both these reporting requirements. 

The conclusions of the After-Action Report include the following: 

• One large whale was sighted on one occasion during the two two-day exercises. 

• The one sighting occurred when no mid-frequency active sonar was being used. 

Therefore, no exposures to marine mammals occurred based on visual sightings. 

• In the one reported sighting, the marine mammal was detected by Navy watchstanders in 

accordance with Navy standard operating procedures and as reiterated by NDE mitigation 

measures. 

• There were no ship and marine mammal collisions during the two exercises and only one 

instance when a U.S. Navy vessel maneuvered to avoid crossing a marine mammal’s 

path. 

• Since there was no need to shutdown or reduce mid-frequency active sonar power levels 

during either USWEX, there was also no lost ASW training opportunities. 

• Improvements to the U.S. Navy lookout reporting procedures will be implemented for 

future exercises to better capture metrics on weather conditions during the sighting, and 

more detailed observations of marine mammal behavior. 

• The U.S. Navy is committed to development of robust exercise and long-term range 

complex monitoring plans that will integrate multiple tools in order to provide better 

assessment of marine mammal occurrence and possible mid-frequency active sonar 

effects, or lack of effects. Plans during fiscal year 2008 may include various mixes of 

ship and aerial surveys independent of exercise participants, validation by experienced 

biologist(s) on lookout effectiveness in observing marine mammals, and use of new 

research and development technologies to advance the state of marine mammal 

monitoring. 

Navy remains committed to working with NMFS and responding to inquiries regarding strandings that 

may occur during or within 24 hours after an ASW training activity as required in NDE measure # 27. As 

the USWEX AAR indicated, there were no known strandings during or within 24 hours after USWEX. 

Nevertheless, in July, 2007, the Marine Mammal Response Network Coordinator for the NOAA Pacific 

Islands Regional Office of NMFS contacted the Navy to ask whether any naval activities occurred prior to 

three stranding events: 1) or on April 15, 2007, when a female pygmy sperm whale was found stranded on 

a remote beach off Lanai City, Lanai; 2) prior to or on April 25, 2007, when a male pygmy sperm whale 

was found at Kihea, Maui; and 3) prior to or on June 30, 2007, when a Stenella (likely spinner) dolphin 

was stranded at Hauula, Oahu. 

None of these strandings have been associated with mid-frequency active sonar or other Navy activities. 

First, with respect to the April 15, 2007, stranding, the Navy indicated that the most recent mid-frequency 

active sonar use had been conducted during the April 10-11, 2007 exercise. The ships participating in the 

exercise were greater than 60 nautical miles from the location the whale stranded. 



As to the April 25, 2007, stranding off Maui, the Navy used fewer than 30 DICASS sonobuoys used on 

April 20, 2007. DICASS sonobuoys are only active for very brief periods and only after there has first 

been a passive acoustic sensor detection. The location of the sonobuoys was greater than 200 nautical 

miles from the stranding site and was separated from the stranding site by four other island masses. 

The Navy identified no mid-frequency active sonar use in the Hawaiian Islands Operating Area during the 

five days preceding the June 30, 2007, dolphin stranding. 

Generally, pygmy sperm whales and spinner dolphins are the most commonly stranded species with the 

Hawaiian Islands. Oahu, Maui and Lanai have the highest reported proportion of cetacean strandings for 

the main Hawaiian islands. (Maldini, D. et al., 2005; Mazzuca, L. et. al., 1999). As of 15 October 2007, 

the necropsy results from the April 2007 stranding were not available from NMFS. 

Given the time and distance previously described involving sonar use and the strandings coupled with 

these stranding falling within typical marine mammal stranding patterns for the main Hawaiian Islands, 

Navy concluded that sonar use is an unlikely cause or contributing factor for any of the three reported 

strandings. 





6.0 Consultation and Coordination 

6.0 CONSULTATION AND 

COORDINATION 

USWEX is a combination of exercises designed and conducted to ensure that the United States can 

accomplish operational objectives in regard to CSGs and ESGs. As such, USWEX is composed of joint, 

routine ongoing military training events, conducted at the locations where they would normally occur as 

individual exercises. 

Coastal Zone Management 

The Navy determined that its USWEX activities will not have a reasonably foreseeable effect on any 

State of Hawaii coastal use or resource and provided Hawaii with a negative determination on August 14 

2007. The Hawaii Coastal Zone Management (CZM) Program responded with an objection to the Navy's 

Negative Determination on October 5, 2007. The Hawaii CZM Program objected on the basis that 

USWEX activities would have a reasonably foreseeable effect on whale watching, Native Hawaiian 

cultural values involving marine mammals, and scenic aesthetic enjoyment of observing whales from the 

coast. The Hawaii CZM Program’s objection was based on the threshold determination of effects and did 

not determine whether the exercises would be conducted in a manner consistent with Hawaii’s 

enforceable policies. Pursuant to federal regulations implementing the CZMA, the Navy has 90 days 

from the time it submitted its Negative Determination to work with the Hawaii CZM Program to attempt 

to resolve the State’s objection (15 CFR 930.35 (c)). The Hawaii CZM Program extended an offer to 

meet with the Navy to discuss its findings and the consistency review process. The Navy has agreed to 

meet with the Hawaii CZM Program and is fully committed to resolving the differences regarding the 

potential effects of the USWEX on Hawaii’s coastal uses or resources. The ongoing process with the 

Hawaii CZM Program under the CZMA is separate from the NEPA process (15 CFR 930.37). 

State Historic Preservation Office Section 106 of the National Historic 

Preservation Act 

Prior consultation has occurred as required by Section 106 of the National Historic Preservation Act and 

defined in 36 CFR Part 800 of the Advisory Council on Historic Preservation’s regulations, Protection of 

Historic Properties, where required, individually for all ongoing training events that are proposed for 

USWEX. Historic properties and cultural resource sites at all involved locations have been previously 

identified and the potential effects evaluated. These potential effects of the individual activities would not 

change when these training events are conducted during USWEX. Procedures and mitigations are in 

place, and sensitive areas have been identified and are avoided. Mitigation measures developed during 

prior consultations have been adopted; subsequently, no activity conducted as a part of USWEX, 

including the AMPHIBEX training events proposed at PMRF and MCTAB, and the STWEX and 

GUNEX activities proposed at Kaula and PTA, would present the potential for changes in the character or 

use of historic properties or cultural resources. Therefore, consistent with 36 CFR 800.4(a)(1) and 

800.2(o), the U.S. Navy has determined that USWEX does not constitute an undertaking because no new 

activities are planned. Instead, it is simply the coordination of ongoing training events that have been 

previously conducted and would be combined into one exercise for USWEX. 

In cases of inadvertent discovery of archaeological resources, historic artifacts, or human remains during 

USWEX training events, the particular training event would be halted and the appropriate Cultural 



Resource Specialist would be contacted and the property or artifact protected in accordance with federal 

law, regulation, and any existing executed agreements. 

Consultation/Coordination with U.S. National Marine Fisheries Service and 

U.S. Fish and Wildlife Service 

MMPA—The methodology applied for analyzing the potential effects of mid-frequency active tactical 

sonar from selected USWEX training events determined there is a potential for Level B harassment of 

marine mammals. As described in Sections 4.1.5.2.10 and 4.2.1, effects on marine mammal species or 

stocks from USWEX ASW training events would be negligible. Any negligible effects can be mitigated 

by protective measures. Further, on January 23, 2007, the Deputy Secretary of Defense signed an NDE to 

exempt all military readiness activities that employ mid-frequency active sonar, either during major 

training exercises, or within established DoD maritime ranges or established operating areas, from 

compliance with the MMPA. This exemption covers activities for 2 years from the signing of the NDE. 

To adhere with the NDE, all exempt military readiness activities employing mid-frequency active sonar 

must follow required protective measures that were coordinated with NMFS and are identified in Section 

5.1.2. 

ESA—Only those USWEX training events with the potential to affect a listed species or designated 

critical habitat or likely to jeopardize proposed species or adversely modify proposed habitat have been 

the subject of previous consultation with both the NMFS and the USFWS. Where they exist, critical and 

proposed critical habitats at all involved locations have been previously identified, and the avoidance and 

monitoring measures normally taken when the training event is conducted individually would be followed 

during USWEX. All previously identified mitigations would be adopted (e.g. approved procedures for 

the prevention of introduction of alien species, surveys of AMPHIBEX beach areas for turtles, turtle 

nesting, and monk seals, determining ocean areas clear of endangered marine mammals prior to training 

events, etc.) 

The training exercises and locations for USWEX are all included in the RIMPAC 2006 Exercise, and 

therefore the information and conclusions from the Biological Opinion for RIMPAC 2006 have been 

considered in the analysis for USWEX. 

Based on the USWEX ASW acoustic model results; analysis presented in Chapter 4 of this document, the 

results of past RIMPAC and USWEX type exercises, and the implementation of standard operating 

procedure protective measures, the U.S. Navy finds that the USWEX ASW training events may affect 

sperm whales, fin whales, sei whales, and humpback whales. Because the USWEX ASW training events 

may affect endangered species, the U.S. Navy consulted with NMFS under Section 7 of the ESA and 

received a Biological Opinion and Incidental Take Statement. The resultant conclusion from the NMFS 

Biological Opinion is as follows: “After reviewing the current status of the endangered fin whale, 

humpback whale, sei whale, and sperm whale, the environmental baseline for the action area, the effects 

of the proposed Undersea Warfare Exercises, and the cumulative effects, it is NMFS’ biological opinion 

that the Navy’s proposed Undersea Warfare Exercises in waters off the State of Hawaii from January 

2007 through January 2009 may adversely affect, but is not likely to jeopardize the continued existence of 

these threatened and endangered species under NMFS jurisdiction.” The Reasonable and Prudent 

Measures and Terms and Conditions required under the Incidental Take Statement (included in Section 

5.1.4 of this EA/OEA) are identified to ensure the Navy’s compliance under ESA during USWEX. A 

copy of the cover letter and memorandums to the USWEX Biological Opinion are included in the 



following pages. As provided in 50 CFR 402.16, reinitiation of formal consultation is required where 

discretionary Federal agency involvement or control over the action has been retained (or is authorized by 

law) and if: (1) the amount or extent of incidental take is exceeded; (2) new information reveals effects of 

the agency action that may affect listed species or critical habitat in a manner or to an extent not 

considered in the biological opinion; (3) the agency action is subsequently modified in a manner that 

causes an effect to the listed species or critical habitat not considered in the biological opinion; or (4) a 

new species is listed or critical habitat designated that may be affected by the action. After examining all 

of these criteria, Navy has determined the reinitiation of consultation is not required. 

All ongoing activities that are conducted in the coastal zone and open ocean areas were the subject of 

consultation during the establishment of the Hawaiian Islands Humpback Whale National Marine 

Sanctuary. As stated in CFR Part 922.183(b), activities allowed within the sanctuary include all classes 

of military activities, internal or external to the sanctuary, that are being or have been conducted before 

the effective date of these regulations, as identified in the Final Environmental Impact 

Statement/Management Plan. No further consultation regarding the sanctuary is required for this action. 

Essential Fish Habitat—Training events conducted during USWEX are not expected to adversely affect 

EFH waters or substrate; therefore, no consultation is required. 

Marine Managed Areas—The marine managed areas Inventory atlas was reviewed. Areas identified 

within the USWEX region of influence include the Hawaiian Islands Humpback Whale National Marine 

Sanctuary. U.S. Navy ASW operations occur on a regular basis within this area, and no adverse impacts 

have been identified. 













7.0 Conclusions and Recommendations 

7.0 CONCLUSIONS AND 

RECOMMENDATIONS 

The analyses in this USWEX EA/OEA conclude that no significant impacts would occur to air quality, 

airspace, biological resources, cultural resources, geology and soils, hazardous materials and waste, land 

use, noise, safety and health, socio-economics, or water quality as a result of implementing the Proposed 

Action Alternatives. In addition, this EA/OEA includes acoustic effects modeling for hull mounted midfrequency 

active tactical sonar. Based on the analysis presented in this EA/OEA and the history of 

previous ASW exercises, no significant impacts on biological resources would occur as a result of 

implementing the Proposed Action Alternatives. 

For open ocean areas, an analysis was conducted for USWEX, modeling the potential interaction of hull 

mounted mid-frequency active tactical sonar with marine mammals in the Hawaiian Islands Operating 

Area. For Alternative 1, the modeled estimate indicates the potential for a total of 30,699 exposures at 

173 dB re 1 µPa 2 -s sub-TTS; 1,585 exposures at 190 dB re 1 µPa 2 -s sub-TTS; 222 exposures at 195 dB re 

1 µPa 2 -s TTS; and no exposures at 215 dB re 1 µPa 2 -s PTS. Under the MMPA, the TTS and sub-TTS 

exposures are considered Level B harassment under the MMPA. There are no predicted marine mammal 

sonar exposures that would result in injury. Because the model predicts Level B exposures of marine 

mammals, the U.S. Navy will employ the mandatory mitigation measures set forth in NDE II. The U.S. 

Navy has also consulted with NMFS and received a biological opinion and incidental take statement for 

compliance under ESA. The training exercises and locations for USWEX are all included in the 

RIMPAC 2006 Exercise, and therefore the analysis and conclusions from the IHA Permit and Biological 

Opinion for RIMPAC 2006 have been considered in the analysis for USWEX. 

The endangered species that may occur in the geographic area of the Proposed Action include the North 

Pacific right whale (Eubalaena japonica), the humpback whale (Megaptera novaeangliae), the sei whale 

(Balaenoptera borealis), the fin whale (Balaenoptera physalus), the blue whale (Balaenoptera musculus), 

the sperm whale (Physeter macrocephalus), the Hawaiian monk seal (Monachus schauinslandi), the 

loggerhead sea turtle (Caretta caretta), the green sea turtle (Chelonia mydas), the hawksbill sea turtle 

(Eretmochelys imbricata), the leatherback sea turtle (Dermochelys coriacea), and the olive ridley sea 

turtle (Lepidochelys olivacea). However, based on the analysis presented herein, the U.S. Navy 

concludes that the proposed USWEX activities would result in no effect to blue whales, North Pacific 

right whales, Hawaiian monk seals, or endangered sea turtles. 

Without consideration of applicable mitigation measures, acoustic effects modeling indicated up to 3 

incidents of sperm whale and 49 incidents of humpback whale exposures to sonar signals that exceed an 

MMPA TTS threshold of 195 dB re 1 µPa 2 -s EL; approximately 23 incidents of sperm whale and 423 

incidents of humpback whale exposures to sonar signals above 190 dB re 1 μPa 2 -s EL; and approximately 

905 incidents of sperm whale, 48 incidents of fin whale, 21 incidents of sei whale, and 10,273 incidents 

of humpback whale exposures to sonar signals above 173 dB re 1 µPa 2 -s EL. Based on the modeling, no 

marine mammals would be exposed to the PTS threshold of 215 dB re 1 μPa 2 -s. 

As noted previously, modeling was undertaken to assess potential effects by estimating the numbers of 

marine mammals that could be exposed to the activities associated with the use of hull-mounted midfrequency 

active tactical sonar during USWEX. The results from that modeling do not represent a 



guarantee of the interaction of sound and mammals since there are factors that will occur relative to the 

modeled parameters, such as the mitigating effect of standard operating procedures serving as protective 

measures. These procedures include measures such as decreasing the source level and then shutting down 

active tactical sonar operations when marine mammals are encountered in the vicinity of a training event. 

Although these protective measures are standard operating procedure, their use is also reinforced through 

promulgation of a Letter of Instruction for each USWEX. 


their vicinity. While conducting the exercise, U.S. Navy ships always have two, although usually more, 

personnel on watch serving as lookouts. In addition to the qualified lookouts, the bridge team is present 

that at a minimum also includes an Officer of the Deck and one Junior Officer of the Deck whose 

responsibilities also include observing the waters in the vicinity of the ship. At night, personnel engaged 

in ASW events may also employ the use of night vision goggles and infra-red detectors, as appropriate, 

which can also aid in the detection of marine mammals. Passive acoustic detection of vocalizing marine 

mammals is also used to alert bridge lookouts to the potential presence of marine mammals in the 

vicinity. 

This USWEX EA/OEA therefore concludes that the Proposed Action and alternatives would result in: 

• No significant impacts in accordance with NEPA. 

• No significant harm to resources in the global commons under EO 12114. 

• No significant impacts to cultural resources. Consistent with 36 CFR 800.4(a)(1) and 800.16(y), 

the U.S. Navy has determined that USWEX does not constitute an undertaking in the sense that 

no new activities are planned. Instead, it is simply the coordination of ongoing training events 

that have been previously conducted and would be combined into one exercise for USWEX. 

• No destruction or adverse modification of any critical habitat in accordance with the ESA. 

• USWEX ASW training events may affect sperm, fin, sei, and humpback whales. As such the 

U.S. Navy consulted with NMFS under Section 7 of the ESA and received a Biological Opinion 

and Incidental Take Statement. 

• A potential for Level B harassment of marine mammals. However, effects to marine mammal 

species or stocks from USWEX training events would be negligible. The use of mid-frequency 

active tactical sonar in ASW training has been occurring in the Hawaiian Islands for 

approximately 40 years using the same basic equipment with no direct evidence of harm to 

marine mammals. The USWEX is an example of ASW training utilizing mid-frequency active 

tactical sonar. Based on decades of ASW training having occurred in the Hawaiian Islands, and 

no direct evidence of marine mammal strandings having occurred in the timeframe of those 

events or otherwise associated with any of those events, it is extremely unlikely that any 

significant behavioral response will result from the interaction of marine mammals and the use of 

sonar during USWEX. Due to the fact that the model predicts potential Level B exposures of 

marine mammals, the U.S. Navy coordinated with NMFS on mitigation measures under the 

MMPA. In order to ensure full compliance with the Marine Mammal Protection Act during 

USWEX, all ships, submarines, and helicopters engaged in mid-frequency active sonar activities 

will adhere to the 29 mitigation measures identified in the NDE signed on January 23, 2007 and 

included in Section 5.1.2 of this EA/OEA. 

• A may affect determination for endangered species. The U.S. Navy consulted with NMFS under 

Section 7 of the ESA and received a Biological Opinion and Incidental Take Statement. The 

NMFS Biological Opinion concluded that USWEX may adversely affect, but is not likely to 



jeopardize the continued existence of threatened and endangered species under NMFS 

jurisdiction. The Reasonable and Prudent Measures and Terms and Conditions required under the 

Incidental Take Statement (included in Section 5.1.4 of this EA/OEA) are identified to ensure the 

Navy’s compliance under ESA during USWEX. 

• No adverse impact to Essential Fish Habitat in accordance with the Magnuson-Stevens Fishery 

Conservation and Management Act. 

• Navy determined that its USWEX activities will not have a reasonably foreseeable effect on any 

State of Hawaii coastal use or resource and provided Hawaii with a negative determination on 

August 14 2007. The Navy and Hawaii CZM Program continue coordinating and are committed 

to resolving differences regarding the potential effects of the USWEX on Hawaii’s coastal uses or 

resources. The ongoing process with the Hawaii CZM Program under the CZMA is separate 

from the NEPA process (15 C.F.R. 930.37). 

Therefore, a finding of no significant impact under NEPA and no significant harm to resources in the 

global commons under EO 12114 is recommended, to document that further analysis associated with an 

Environmental Impact Statement or Overseas Environmental Impact Statement is not required. 





8.0 Other Considerations 

8.0 OTHER CONSIDERATIONS 

8.1 ADVERSE ENVIRONMENTAL EFFECTS THAT CANNOT BE 

AVOIDED 

Unavoidable short-term effects would be associated with temporary closure of beach areas during 

amphibious landings at PMRF and MCTAB. However, the amount of closure time would not result in 

any long-term impacts to recreational activities or subsistence fishing uses. 

Other unavoidable effects, such as the startling of wildlife, marine and terrestrial species, and some 

threatened and endangered species, would result from firing of weapons. Similar training is ongoing, and 

the resources are adapted or existing mitigations are working. In addition, noise from U.S. Navy ships 

may also impact marine species. Noise from other activities such as helicopters and aircraft may startle 

wildlife. The impacts from these noise sources would be short-term and are not expected to jeopardize 

the existence of any threatened, endangered, or marine species. 

8.2 CONSISTENCY WITH FEDERAL, REGIONAL, STATE, LOCAL, OR 

NATIVE AMERICAN LAND-USE PLANS, POLICIES, AND 

CONTROLS 

Neither the Proposed Action nor the No-Action Alternative conflicts with any land use plans, policies, or 

controls as summarized below: 

• The Proposed Action will be conducted on government and private land in accordance with the 

Hawaii CZM program. 

• The Proposed Action would be compatible with State of Hawaii, county, and local land use plans, 

policies, and controls. 

8.3 ENERGY REQUIREMENTS AND CONSERVATION POTENTIAL 

Anticipated energy requirements of program activities can be accommodated within the energy supply of 

the region. Energy requirements would be subject to any established energy conservation practices. 

8.4 IRREVERSIBLE OR IRRETRIEVABLE COMMITMENT OF 

RESOURCES 

The amount of materials and energy required for any program-related activities would be small. 

Although the proposed activities would result in some irreversible and irretrievable commitment of 

resources such as fuel, various metallic materials, minerals, and labor, this commitment of resources is 

not significantly different from that necessary for many other defense training activities. It is similar to 

the activities that have been carried out in previous ESG and CSG training exercises over the past several 

years. 



8.5 RELATIONSHIP BETWEEN SHORT-TERM USES OF THE HUMAN 

ENVIRONMENT AND THE MAINTENANCE AND ENHANCEMENT 

OF LONG-TERM PRODUCTIVITY 

Proposed USWEX activities at all locations would take advantage of existing facilities and infrastructure. 

The proposed activities would not alter the usage of the sites, which is to support training and testing. 

Therefore, the Proposed Action would not eliminate any options for future use of the environment for the 

locations under consideration. 

8.6 NATURAL OR DEPLETABLE RESOURCE REQUIREMENTS AND 

CONSERVATION POTENTIAL 

Other than the use of various structural materials and fuels, no significant use of natural or depletable 

resources would be required for USWEX activities. 

8.7 FEDERAL ACTION TO ADDRESS ENVIRONMENTAL JUSTICE IN 

MINORITY POPULATIONS AND LOW-INCOME POPULATIONS 

EO 12898, Federal Actions to Address Environmental Justice in Minority Populations and Low-income 

Populations, requires federal agencies to identify disproportionately high and adverse human health and 

environmental effects of their actions on minority and low-income populations. Based on the findings 

presented in this EA/OEA, implementation of the Proposed Action would have little likelihood of having 

disproportionate impacts on any low-income or minority groups. 

8.8 FEDERAL ACTION TO ADDRESS PROTECTION OF CHILDREN 

FROM ENVIRONMENTAL HEALTH RISKS AND SAFETY RISKS 

EO 13045, Protection of Children from Environmental Health Risks and Safety Risks, requires federal 

agencies to identify any adverse impacts for a federal action on the health and safety of children. 

Implementation of the Proposed Action would have little likelihood of any significant adverse impacts on 

the health and safety of children living near any of the ranges or facilities to be utilized during any 

USWEX exercise. 

8.9 PUBLIC NOTICE AND COMMENT 

On September 14, 2007, the Navy initiated a 21-day public comment period on its initial EA/OEA for the 

USWEX. The Navy sent notice of the public comment period directly to interested parties and published 

the Notice in the Honolulu Advertiser and the Honolulu Star-Bulletin. The notices ran in those 

newspapers from September 14, 2007, through September 16, 2007, a period of 3 days. The notice 

described the USWEX and indicated that the EA/OEA was available for public review on an Internet 

website and the hard copies of the EA/OEA were available for review at the Wailuku Public Library, Hilo 

Public Library, Hawaii State Library in Honolulu, and the Lihue Public Library. Comments were 



accepted by regular mail and electronic mail through October 5, 2007. These comments were analyzed 

by the Navy, incorporated into the current EA/OEA, and considered by the Navy in its NEPA analysis. 

During the public comment period opportunity, 13 submissions containing approximately 97 comments 

were received (see Appendix D). Comments came from environmental organizations as well as the 

Office of Hawaiian Affairs, the Hawaii CZM Program, the International Noise Coalition, and two private 

individuals. The Navy determined that none of the comments received during the public comment period 

altered its January 2007 determination that the USWEXs will not have a significant effect on the quality 

of the human environment. The comments received were considered in the revision of this EA/OEA and 

are summarized in the following paragraphs under general subheadings. 

8.9.1 Thresholds for Modeling 

Many of the comments argued against the thresholds in the EA/OEA used for assessing potential acoustic 

impacts on marine mammals. The comments were generally that the thresholds were too low or that the 

metric used (such as PTS for onset of injury) were not sufficiently conservative given the potential for 

secondary effects resulting from any exposure to sound. Regarding the issue of the thresholds being too 

low, as detailed in Section 4.1.5.2.2, the data from experiments clearly establish the TTS metric as 

appropriate given that, by definition, it does not result in any direct injury. While commenters have 

criticized this data, it is the only scientifically established criteria NMFS has approved to date that clearly 

establishes a non-injury threshold. Regarding criticism of the threshold for behavioral effects (173 dB 

SEL), Navy used the metric established by NMFS and it is based on the only controlled experiment using 

a source restricted to the mid-frequency range used by the existing Navy mid-frequency active sonar 

systems. Beyond this experimental data, there is no clearly established metric upon which to base 

behavioral thresholds because energy levels above ambient levels have the potential to cause a behavioral 

reaction. Although these commenters have expressed their disagreement with the NMFS-approved 

standards, the Navy recognizes that NMFS has considerable scientific expertise and experience in 

adopting the existing standards and criteria, and the Navy has adopted them for its modeling approach. 

8.9.2 Lack of Evidence of Impacts or Sonar Related Strandings in Hawaii 

Many comments argued against the EA/OEA reference to the lack of strandings or any documented 

decline in the marine mammal populations around Hawaii as an indication that sonar use over 40 years 

was having no apparent effect on marine mammals. Reasons given were that all whales and dolphins 

impacted by sonar in Hawaii will sink, be eaten, or lie undiscovered on “remote beaches” and that NMFS’ 

stock assessments did not provide information on trends. Given that all evidence suggesting that sonar 

may have caused some impacts to marine mammals comes from strandings of both live and floating 

(dead) animals, the concern that all whales will sink when affected by sonar in Hawaii is inconsistent with 

the lack of evidence that marine mammal populations are decreasing. In addition, approximately two 

strandings per month (of both live animals and dead animals) are discovered on shores in the Hawaiian 

Islands as a result of normal mortality, fishery interactions or other undetermined assumingly natural 

causes according to the Pacific Islands Stranding coordinator (personal communication, David Schofield, 

2006). Again, the assertion that strandings in Hawaii will not be encountered is without basis and 

contrary to available evidence. Furthermore, the contention that there are “unmonitored beaches” where a 

stranding of any magnitude could go unnoticed leaving dead whales in the shore is not consistent with the 

number of fishing boats, hikers, and helicopter and aircraft overflights in the Hawaiian Islands leaving 



very few shorelines “remote.” While the lack of documented strandings associated with sonar use in 

Hawaii does not prove no impacts could have occurred, 40 years of experience without any evidence of 

strandings strongly indicates that impacts are unlikely. 

8.9.3 Non-auditory impacts: 

Comments in this regard expressed concern that the Navy did not account for non-auditory impacts from 

sonar on marine mammals including masking, stress, interruptions of breeding/nursing behavior or 

impacts of bubble growth or even resonance. Section 4.1.5.2.11 of the EA/OEA discussed other effects 

considered, including acoustically mediated bubble growth and resonance. The remainder of the issue is 

the same as discussed above in regard to the potential for secondary impacts. In addition, there is no 

information upon which to quantitatively or qualitatively assess the potential for impacts relating to 

criteria such as stress or temporary interruptions of behavior given the current state of science regarding 

marine mammals. While the comments suggest a use of the precautionary principle, with the Navy 

suspending use of sonar until negative evidence is gathered, there is no scientific evidence to support that 

sudden change in training. Moreover, the Navy is committed to continuing to support scientific research 

regarding potential impacts of sonar use on marine mammals, and suspension of critical training would 

not allow the Navy to meet its mandated requirements. 

8.9.4 Sonar Mitigations 

Comments in this regard were critical of the standard operating procedures and proposed sonar mitigation 

use asserting it is ineffective. A subset of these comments also suggested that the Navy should avoid 

sonar use when certain conditions are present. In general, an ineffectiveness of the mitigation was 

asserted given that the mitigation measures could not prevent all exposures to all marine mammals. 

Reasons cited included assertions such as Navy lookouts and bridge personnel were not trained or were 

not as effective as trained marine mammal observers, marine mammals were hard to detect, and that 

procedures may miss detecting long-diving and cryptic species. Section 5.1.2 of the EA/OEA detailed the 

mitigation measures and the training undertaken in this regard. 

Comments failed to recognize there was no reduction in the calculated number of marine mammals 

exposed as a result of the mitigations and that the Navy never claimed or suggested that the proposed 

mitigations would be completely (100%) preventative. The Navy’s mitigation measures were designed to 

mitigate direct impacts to the maximum extent practicable. There were no new mitigations presented in 

comments that were not previously considered in some form. Comments suggesting the Navy avoid 

sonar use around “sensitive habitats” such as “steep seamounts” or that the Navy restrict sonar use to 

seasons when marine mammals are not present were addressed in the RIMPAC After-Action Report, 

which the Navy has incorporated as Appendix C in this EA. 

8.9.5 Population impacts: 

Many comments argued against the use of marine mammal density data provided by the NMFS stock 

assessment as a basis for modeling. Section 3.5.2.5 described in detail (including the coefficient of 

variation for each) the limitations of the data that constitutes the best available science. Modeling also 

made many assumptions erring on the side of over counting the potential exposures of marine mammals 

to sonar. Under regulatory requirements, the Navy must assess impacts on the stock as defined by the 



regulator (NMFS). When science has progressed and provided additional and reliable data and analysis 

so that assessments can be made on groups of animals within a stock, the Navy will then adopt any 

emerging regulatory requirements resulting. 

8.9.6 Cumulative Impacts 

Comments in this regard expressed concern that cumulative impacts must be considered or that they had 

not been adequately addressed. Section 4.2 of the original EA/OEA detailed cumulative impacts; 

however, this section of the revision has been updated with an expanded discussion. While this expanded 

discussion includes no substantive information or conclusions that would have changed the January 2007 

FONSI determination, it does provide the public with a fuller appreciation of the magnitude of Navy 

actions in comparison to known impacts from activities such as whale watching and fishing. 

8.9.7 Other 

Comments under this category expressed concern that the EA/OEA did not provide in-depth analysis of 

possible acoustic impacts on non-marine mammal species, that Native Hawaiian cultural impacts were 

overlooked, that the Navy failed to comply with the CZMA and the National Marine Sanctuaries Act, and 

concern with the lack of a public comment period after issuing the January 2007 FONSI. The Navy has 

reviewed and taken a careful look at each of these comments and has determined that none of the 

comments or critiques require additional responses to or changes in the EA. 





9.0 References 

9.0 REFERENCES 

Two primary references for this EA/OEA are: (1) U.S. Department of the Navy, Commander, U.S. Pacific 

Fleet, 2005, Marine Resources Assessment for the Hawaiian Islands Operating Area, Final Report, 

December and (2) U.S. Department of the Navy, Commander, Third Fleet, 2006, 2006 Supplement to the 

2002 Programmatic RIMPAC Environmental Assessment. Within this USWEX EA/OEA, the original 

references from these two documents were retained within the text to maintain readability and provide the 

reader with insight into specific scientific research used in the preparation of the original documents. The 

references from these two documents include a superscript 1 or 2 at the beginning of the citation 

according to the above reference number. Several public comments provided references to studies or 

reports that were published in 2007, following issuance of the January 2007 FONSI. The Navy has 

examined these references and, where appropriate, added them to this list. 

2 Amoser, S., and Laidich F., 2003. Diversity in noise-induced temporary hearing loss in otophysine 

fishes. J Acoustic Am. 2003 Apr; 113 (4 Pt 1): 2170-9. 

2 André, M., M. Terada, and Y. Watanabe, 1997. “Sperm Whale (Physeter macrocephalus) Behavioral 

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10.0 List of Preparers 

10.0 LIST OF PREPARERS 

Government Preparers 

Connie Chang, Environmental Engineer 

Naval Facilities Engineering Command, Pacific 

M.S. Engineering, 1983, Purdue University 

B.S. Engineering, 1982, University of Hawaii 

Years of Experience: 22 

Conrad Erkelens, Environmental Protection Specialist 

Commander in Chief, U.S. Pacific Fleet 

M.A., Anthropology, 1993, University of Hawaii 

B.A., Anthropology, 1989, University of Hawaii 


Dean W. Leech, CDR, JAGC 

U.S. Navy, Judge Advocate, U.S. Pacific Fleet 

J.D., 1985, LLM (Environmental), 2001 


Contractor Preparers 

Bruce Campbell, Principal Scientist, Parsons Infrastructure & Technology 

M.S., Environmental Management, 1989, University of San Francisco 

B.S., Environmental Biology, 1974, University of California, Santa Barbara 


Eloise Emery, J.D., Senior NEPA Project Manager, BMT Designers and Planners 

J.D., 1983, Thomas Jefferson School of Law 


Jonathan Henson, GIS Analyst, KAYA Associates, Inc. 

B.S., 2000, Environmental Science, Auburn University 


Rachel Y. Jordan, Environmental Scientist, KAYA Associates, Inc. 

B.S., 1972, Biology, Christopher Newport College, Virginia 


Edd V. Joy, Manager, KAYA Associates, Inc. 

B.A., 1974, Geography, California State University, Northridge 


Amy McEniry, Technical Editor, KAYA Associates, Inc. 

B.S., 1988, Biology, University of Alabama in Huntsville 



10.0 List of Preparers 

Wesley S. Norris, Managing Senior, KAYA Associates, Inc. 

B.S., 1976, Geology, Northern Arizona University 


Philip H. Thorson, Senior Research Biologist, SRS Technologies 

Ph.D., 1993, Biology, University of California at Santa Cruz 


Neil Sheehan, Manager, KAYA Associates, Inc. 

BA, 1985, State University of New York at Buffalo 

JD, 1988, University of Dayton School of Law 

LL.M, 1998, George Washington University School of Law 


Karen M. Waller, Senior Program Manager, SRS Technologies 

B.S., 1987, Environmental Affairs, Indiana University 


Rebecca J. White, Environmental Engineer, KAYA Associates, Inc. 

B.S., 2000, Civil/Environmental Engineering, University of Alabama in Huntsville 



Appendix A 

APPENDIX A 

THREATENED AND ENDANGERED 

SPECIES LISTS 

Table A-1. Threatened and Endangered Terrestrial Species at PMRF 

Scientific Name Common Name (Hawaiian Name) Federal Status 

Plants 

Panicum niihauense (Lau'ehu) E 

Sesbania tomentosa (Ohai) E 

Birds 

Anas wyvilliana Hawaiian duck (Koloa-maoli) E 

Asio flammeus sandwichensis Hawaiian short-eared owl (Pueo) SOC 

Fulica americana alai American/Hawaiian Coot ('Alae-ke'oke'o) E 

Gallinula chloropus sandvicensis Hawaiian Gallinule/common moorhen ('Alae-'ula) E 

Himantopus mexicanus knudseni Hawaiian black-necked stilt (Ae'o) E 

Pterodroma phaeopygia sandwicense Hawaiian dark-rumped petrel (‘Ua’u) E 

Puffinus auricularis newelli Newell's shearwater (A'o) T 

Mammals 

Chelonia mydas Green sea turtle T (E) 

Lasiurus cinereus semotus Hawaiian hoary bat (Ope’ape’a) E 

Monachus schauinslandi Hawaiian monk seal E 

Source: U.S. Fish and Wildlife Service, 1999a. 

Key to Federal Status: 

E = Endangered 

SOC = Species of Concern 

T = Threatened 

Table A-2. Threatened and Endangered Wildlife at MCTAB 

Scientific Name Common Name Federal Status 

Himantopus mexicanus knudseni Black-necked stilt (Ae’o) E 

Anas wyvilliana Hawaiian duck (Koloa) E 

Fulica alai Hawaiian coot (‘Alae’ula Ke’oke’o) E 

Gallinula chloropus sandvicensis Common moorhen (‘Alae’ula) E 

Chelonia mydas Green sea turtle T 

Eretmochelys imbricata Hawksbill turtle E 

Monachus schauinslandi Hawaiian monk seal E 

Source: U.S. Pacific Command, 1995. 





October 2007 USWEX EA/OEA A-1

Appendix A 

Table A-3. Threatened and Endangered Vegetation at PTA 


Asplenium fragile var. insulare Fragile fern E 

Chamaesyce olowaluana Maui milk tree (‘Akoko, kokomalei) SOC 

Cystopteris douglasii No common name SOC 

Dubautia arborea (Na’ena’e) SOC 

Eragrostis deflexa Bent love grass SOC 

Exocarpos gaudichaudii Whisk broom sandalwood (Heau) SOC 

Festuca hawaiiensis Hawaiian fescue SOC 

Haplostachys haplostachya Hawaiian mint (Honohono) E 

Hedyotis coriacea Leather leaf sweet ear (Kio’ele) E 

Isodendrion hosakae (aupauka) E 

L. venosa (nehe) E 

Melicope hawiaiensis (manena) SOC 

Neraudia ovata Spotted nettle bush (Ma’aloa, ma’oloa) E 

Portulaca sclerocarpa Hard-fruit purslane (‘Ihi) E 

Portulaca villosa Hairy purslane SOC 

Schiedea hawaiiensis (ma’oli’oli) SOC 

Silene hawaiiensis Hawaiian catchfly T 

Silene lanceolata Lanceleaf catchfly E 

Solanum incompletum (Popolo ku mai) E 

Spermolepis hawaiiensis Hawaiian parsley E 

Stenogyne angustifolia Creeping mint E 

Tetramolopium arenarium var. arenarium (Mauna Kea) E 

T. leconsaguinium ssp. Leptophyllum var. leptophyllum Narrow leaf pamakani SOC 

Vigna o-wahuensis (mohihihi) E 

Zanthoxylum hawaiiense Hawaiian yellow wood (Hea’e, a’e) E 

Source: U.S. Army, 2004; U.S. Army Garrison, Hawaii, and U.S. Army Corps of Engineers, 1997. 





A-2 USWEX EA/OEA October 2007

Appendix A 

Table A-4. Threatened and Endangered Wildlife at PTA 


Invertebrates 

Euconulus (Nesoconulus) sp. Cf. gaetanoi snail SOC 

Helicoverpa confuse Hawaiian helicoverpa moth SOC 

Leptachatina spp. (5 species) Amastrid land snail SOC 

Leptachatina lepida Amastrid land snail SOC 

Nesopupa (Infranesopupa) subcentralis NCN SOC 

Nesovitrea haeaiiensis NCN SOC 

Philonesia, sp. NCN SOC 

Rhyncogonus giffardi Goffard’s rhyncogonus weevil SOC 

Striatura (Pesudohyalina) sp. Cf. Meniscus NCN SOC 

Striatura sp. NCN SOC 

Succinea konaensis NCN SOC 

Vitrina tenella NCN SOC 

Birds 

Branta sandvicensis Hawaiian goose (Nene) E 

Buteo solitarius Hawaiian hawk (‘io) E 

Hemignathus munroi (‘Akiapola’au) E 

Loxoiides bailleui (Palila) E 

Pterodroma phaeopygia sandwichensis Hawaiian dark-rumped petrel (‘Ua’u) E 

Mammals 

Lasiurus cinereus semotus Hawaiian hoary bat (‘Ope’ape’a) E 

Source: U.S. Army, 2004; U.S. Army Garrison, Hawaii, and U.S. Army Corps of Engineers, 1997. 





Appendix A 

Table A-5. Threatened and Endangered Marine Mammals and Sea Turtle Species 

in Open Ocean Areas 

Scientific Name 

Marine Mammals 1 

Common Name 

Federal (State) 

Status 

Time Period Within 

Area 

Monachus schauinslandi Hawaiian Monk Seal E (E) Year Round 

Nonmigratory 

Balaenoptera musculus Blue Whale E (E) Year Round Winter 

Mating/Calving 

Period 

June-July/April- 

May 

Balaenoptera physolus Fin Whale E (E) Year Round November/ 

February 

Megaptera novaeangliae Humpback Whale E (E) November to April Winter 

Balaenoptera borealis Sei Whale E (E) Fall & Winter October/March 

Physeter macrocephalus Sperm Whale E (E) Year Round April/August 

Sea Turtles 

Mating/Nesting 

Period 

Eretmochelys imbricata Hawksbill Sea Turtle E (E) Year Round Early Spring/Fall 

Lepidochelys olivacea Olive Ridley Turtle E (E) Year Round, offshore Spring/Early 

Summer 

(Dermochelys coriacea) Leatherback Turtle E (E) Year Round, offshore Spring/Early 

Summer 

Chelonia mydas Green Sea Turtle T (E) Year Round in Warm 

Water 

Caretta caretta Loggerhead Sea Turtle T (T) Year Round in Warm 

Water, Visitor 

Source: U.S. Department of the Navy, 2005a; U.S. Fish and Wildlife Service, 1999b. 

1 All marine mammals are protected under the Marine Mammals Protection Act. 




Early Spring/Fall 

Late Winter/ 

Early Spring 


Appendix A 

APPENDIX A REFERENCES 

U.S. Army, 2004. Stryker Brigade Environmental Impact Statement. 

U.S. Army Garrison, Hawaii, and U.S. Army Corps of Engineers, 1997. Final Endangered Species 

Management Plan Report for the Pohakuloa Training Area, October. 

U.S. Fish and Wildlife Service, 1999a. Comments received from the U.S. Fish and Wildlife Service, 

Pacific Islands Ecoregion, on PMRF species list provided as part of the Mountaintop Surveillance 

Test Integration Center Facility Environmental Assessment, 26 August. 

U.S. Fish and Wildlife Service, 1999b. “Hawaiian Islands Animals: Updated November 29, 1999, Listed 

and Candidate Species, as Designated under the U.S. Endangered Species Act.” 

U.S. Pacific Command, 1995. Bellows Air Force Station Land Use and Development Plan EIS. 

U.S. Department of the Navy, Commander, U.S. Pacific Fleet, 2005. Marine Resources Assessment for 

the Hawaiian Islands Operating Area, Final Report, December. 


Appendix A 



Appendix B 

APPENDIX B 

USWEX ACOUSTIC MODELING RESULTS 

B.1 OVERVIEW 

Every active sonar operation includes the potential to expose marine animals in the neighboring waters 

acoustic energy. The number of animals exposed in any such action is dictated by the propagation field 

and the manner in which the sonar is operated (i.e., source level, depth, frequency, pulse length, 

directivity, platform speed, repetition rate). For the Undersea Warfare Exercise (USWEX), the sole 

relevant measure of potential harm to the marine wildlife due to sonar operation is the accumulated 

(summed over all source emissions) energy flux density received by the animal over the duration of the 

activity. 

Estimating the number of animals that may be exposed in a particular environment entails the following 

steps. 

1. Each source emission is modeled according to the particular operating mode of the sonar. 

The “effective” energy source level is computed by integrating over the bandwidth of the 

source, scaling by the pulse length, and adjusting for gains due to source directivity. The 

location of the source at the time of each emission must also be specified. 

2. For the relevant environmental acoustic parameters, transmission loss (TL) estimates are 

computed, sampling the water column over the appropriate depth and range intervals. TL 

data are sampled at the typical depth(s) of the source and at the nominal frequency of the 

source. If the source is relatively broadband, an average over several frequency samples may 

be required. 

3. The accumulated energy within the waters that the sonar is operating is sampled over a 

volumetric grid. At each grid point, the received energy from each source emission is 

modeled as the effective energy source level reduced by the appropriate propagation loss 

from the location of the source at the time of the emission to that grid point. 

4. The exposure volume for a given threshold (that is, the volume for which the accumulated 

energy exceeds the threshold) is estimated by summing the incremental volumes represented 

by each grid point for which the accumulated energy flux density exceeds that threshold. 

5. Finally, the number of exposures is estimated as the “product” (scalar or vector, depending on 

whether an animal density depth profile is available) of the impact volume and the animal 

densities. 

The factors affecting the acoustic impact of the USWEX action fall into four general categories: 

environment, transmission loss, impact volume, and animal densities; an accounting of their contributions 

to the USWEX impact is detailed in this Appendix. 

Environmental factors, such as sound velocity profile, bottom type, depth, and season, are unique to the 

location and time of USWEX, usually cannot be controlled, and often exert mutual influence. The 

operating environment determines the sound propagation characteristics, so quantification and 

organization of environmental factors are the first steps in determining action impact. Since the 

October 2007 USWEX EA/OEA B-1

Appendix B 

environment changes in space and time, the activity must be organized into provinces (space) and seasons 

(time) of similar situation with respect to the operation. USWEX is organized into eight provinces and 

two seasons. Quantification assigns a number, or numbers, to the important environmental features of 

each province and season, using U.S. Navy-standard environmental databases from the Oceanographic 

and Atmospheric Master Library and other measurements as applicable. 

TL is the difference between the source level and the received sound level measured at a point, in decibels 

(dB). For USWEX, the Navy-standard Comprehensive Acoustic System Simulation/Gaussian Ray 

Bundle Model (CASS/GRAB) Transmission Loss Model is used to predict TL in a two-dimensional 

(range and depth) grid of points from the source for the unique environmental characteristics of each 

USWEX province-season. 

Impact volumes measure the volume of water ensonified beyond a certain energy threshold. The effective 

energy source level is the product of the energy source level and time. The effective source level is then 

reduced by the predicted TL to produce the received energy level due to one ping. Using ping period and 

platform speed, the energy for additional pings at different locations is then summed to calculate the 

received energy level at each point in the field. The impact volume at a given depth is a function of the 

number of points ensonified beyond the threshold at that depth in this grid. 

Animal densities are reported in two dimensions (animals per square kilometer), but the impact metric is 

volume, so they have to be translated into three dimensional densities. The source of the USWEX twodimensional 

densities is the RIMPAC acoustic modeling report (Cembrola, 2005), with the exception of 

wintering humpbacks, which were derived from Mobley (2001). Distributing these two-dimensional 

animal densities uniformly across their respective depth regimes projects them into three dimensions. 

The complete process for estimating animal exposures is summarized in Figure B-1. 

All USWEX sonar activity was modeled within six anti-submarine warfare (ASW) acoustic exposure 

modeling areas around the Hawaiian Islands, as shown in Figure B-2. 

The total sonar hours used in each modeling area annually, shown below in Table B-1, form the basis for 

the exposure estimation spreadsheets at the end of this Appendix. Half of the USWEX sonar hours are 

expected to occur in the summer, and half in the winter. 

ASW Acoustic 

Exposure Modeling 

Area 

Total Sonar Hours 

per USWEX at 

Each Area 

Table B-1. USWEX Sonar Hours 

Number of Ships 

Number of 

USWEX Events 

Annually 

Total Sonar Used 

in Each Area 

Annually 

1 15.5 3 2 93 

2 15.5 3 2 93 

3 15.5 3 2 93 

4 26 3 4 312 

5 4 3 4 48 

6 44 3 4 528 

B-2 USWEX EA/OEA October 2007

Appendix B 

Environment: 

Organize USWEX 

provinces/seasons. 

Operation Location, Time Data 

OHML Data 

Quantify province-season 

characteristics. 

Transmission Loss: CASS- 

GRAB predicts TL grid 

around source for each 

province-season. 

2D Densities (from RIMPAC) 

Exposure Volumes: 

Use source characteristics to calculate 

energy footprint for each province-season. 

Use source characteristics to sum 

footprints and calculate received energy 

field. Consolidate energy field to 

determine volume ensonified by depth. 

Depth Regimes and 2D 

Humpback Densities 

Animals: 

Gather 2D densities and 

animal depth regime. 

Generate three 

dimensional densities by 

animal. 

Exposures: 

Number of 

Expected 

Exposures 

Figure B-1. USWEX Exposure Estimation Process Summary 


Appendix B 


Appendix B 

B.2 ENVIRONMENT 

Within a single modeling area, many different environmental conditions can occur, so the modeling areas 

themselves cannot be environmental provinces. A closer look at the different environmental factors at 

play in the Hawaii ocean area allows a determination of their importance and a way to group similar 

factors together to reduce the problem. The data sources for environmental inputs are the Navy Standard 

Digital Bathymetry Data Base Variable Resolution, the Sediment Thickness Data Base, the Low- 

Frequency Bottom Loss Data Base, and the High-Frequency Bottom Loss Data Base. 

B.2.1 Sound Speed Profile 

Pressure, temperature, and salinity determine the sound speed in water and, since they vary with depth, 

sound speed similarly varies. The nature of the change can produce dramatic effects on sound 

propagation including features such as surface ducts, convergence zones, and sound channels, and other 

consequences of sound refraction. 

Although Hawaii has mild winters, the difference in water temperature between summer and winter is still 

significantly different enough, especially in the upper 100 meters of water, to warrant the modeling of 

seasonal variation in the provinces between winter and summer. 

Within a season, there is not much difference in sound speed profile across the modeling areas. This 

permits a single sound speed profile for each season to cover all modeling areas. 

B.2.2 Bathymetry 

Bathymetry varies extremely within and across the modeling areas, covering depths to 5 kilometers. The 

representative depths assigned to the USWEX provinces are 100, 200, 500, 1,000, 2,000, and 5,000 

meters. Only 1% of the modeling areas occur in provinces that are shallower than 1 kilometer, 3% 

shallower than 2 kilometers, and 11% less than 5 kilometers. However, although most of the USWEX 

operating area is in deep water, shallow-water interaction is not ignored. 

B.2.3 Bottom Type and Sediment Thickness 

The shallow provinces (100-500 meters) make up a small percentage of total modeling area where the 

variability in shallow-water bottom types is severely limited. The deep provinces (5 kilometers in depth) 

dominate the modeling areas and span three bottom-loss provinces in USWEX. Each of these bottomloss 

provinces is used to partition the USWEX environmental provinces. 

B.2.4 Provinces 

Other environmental factors are not sufficiently important in USWEX to cause further division of the 

provinces. With the six depth regimes and the 5-kilometer depth province being divided into three with 

different bottom types, a total of eight fundamental provinces are used to describe the USWEX modeling 

areas. Each modeling area is made up of a linear combination of this environmental “basis.” The 

distribution of environmental provinces across the six modeling areas is depicted in Figure B-3. 

The environmental province is now the fundamental unit of calculation. Once the exposure count per 

sonar-hour is determined for each environmental province, the exposure counts per sonar-hour of each 

modeling area can be calculated with the proper linear combination of the provincial exposure counts. 

Most of the steps in the rest of this Appendix work toward determining the provincial hourly exposure 

counts. 


Appendix B 

24 

23 

Latitude 

22 

21 

20 

19 

-161 -160 -159 -158 -157 -156 

Longitude 

Figure B-3. USWEX Modeling Areas as Represented by Environmental Provinces 

B.3 TRANSMISSION LOSS 

TL data are pre-computed for each of two seasons in the eight environmental provinces using the GRAB 

propagation loss model (Keenan, et al., 2000). A description of these provinces along with an 

explanation of the methodology used to define these provinces is provided in Section B.2. The TL output 

consists of a parametric description of each significant eigenray (or propagation path) from source to 

animal. The description of each eigenray includes the departure angle from the source (used to model the 

source vertical directivity later in this process), the propagation time from the source to the animal (used 

to make corrections to absorption loss for minor differences in frequency and to incorporate a surfaceimage 

interference correction at low frequencies), and the transmission loss suffered along the eigenray 

path. 

The transmission loss was calculated separately for each USWEX environmental province using 

CASS/GRAB propagation model. CASS/GRAB modeled the sound propagation in each province's 

unique environment in summer and winter. This modeling provided a grid with the transmission loss (in 

received power level) from the source to each point in the grid. This grid is constructed by programming 

CASS/GRAB to predict the transmission loss every 5 meters in depth to 1,000 meters, and every 10 

meters at depths beyond 1,000 meters. This is done every 20 meters of horizontal distance from the 

source. 


Appendix B 

With the assumption that sound propagates symmetrically about the source, the complete threedimensional 

grid about the source is created by assigning each point the transmission loss associated with 

its distance and depth. This grid is produced for each province in summer and winter—a total of 16 grids. 

B.4 EXPOSURE VOLUMES 

Energy level is equal to the integral of the power level squared, with respect to time in seconds. To 

convert the sound pressure level grid to an energy level “footprint” each grid point's value must be 

multiplied by the (classified) pulse length (in seconds). The footprint gives the energy added by a single 

ping to the water in three dimensions around the source. Since the USWEX source is moving across the 

surface of the water, this footprint was applied along the source path every vp miles, where v is the 

velocity of the ship, and p is the period of the sonar ping. Many grid points receive energy from multiple 

pings, which is summed at each grid point. 

B.4.1 Footprint Size Calculation 

The sound pressure of an acoustic wave and the energy it delivers to a point in a certain time can be very 

small for a point far away but still positive. So a true footprint includes hundreds of miles of infinitesimal 

energy contributions. However, the sum of the energy contributions beyond a certain point does not 

materially change the calculated volume of water exposed to beyond threshold levels. 

How far out should the USWEX footprint be calculated Each ping's footprint ensonifies a volume of 

water immediately surrounding it as well as a bit of additional volume around the edges of previous 

footprints; specifically, those volumes that contained near-threshold energy levels and are pushed over the 

threshold by the (distant) ping’s small energy contribution. The complication is that, regardless of how 

small the energy addition, there is always a bit of volume at every footprint that is that far below the 

energy threshold. Therefore, regardless of how far away the ping, it will ensonify some additional 

volume at the edge of a previous footprint. This volume is too small to matter, however, if the ping is 

sufficiently distant. How distant Practically, this question is answered by counting the pings generated 

by the moving platform until the first footprint's volume is no longer appreciably affected, then increasing 

the footprint size by 10% and counting again. Once the two numbers are the same, the footprint is 

sufficiently large. Note that a footprint’s required size is a direct consequence of the propagation 

environment, so the required distance to calculate a single footprint changes with environment (province). 

B.4.2 Energy Summation 

The summation of energy flux density over multiple pings in a range-independent environment is a trivial 

exercise for the most part. A volumetric grid that covers the waters in and around the area of sonar 

operation is initialized. The source then begins its set of pings. For the first ping, the TL from the source 

to each grid point is determined (summing the appropriate eigenrays after they have been modified by the 

vertical beam pattern), the FOM is reduced by that TL, and the result is added to the accumulated energy 

at that grid point. After each grid point has been updated, the accumulate energy at grid points in each 

depth layer are compared to 0 dB. (Note that the benchmark for comparison is zero dB because the actual 

energy threshold is already included in the FOM that was used as the effective source level in computing 

the energy flux density.) If the accumulate energy exceeds 0 dB, then the incremental volume represented 

by that grid point is added to the exposure volume for that depth layer. Finally, the total exposure volume 

is simply the sum of the exposure volumes across all depth layers. 


Appendix B 

The source is then moved along one of the axes in the horizontal plane by the specified ping separation 

distance, and the second ping is processed in a similar fashion. This procedure continues until the 

maximum number of pings specified has been reached. 

Defining the volumetric grid over which energy is accumulated is the trickiest aspect of this procedure. 

The volume must be large enough to contain all volumetric cells for which the accumulated energy is 

likely to exceed the threshold but not so large as to make the energy accumulation computationally 

unmanageable. 

Defining the size of the volumetric grid begins with an iterative process to determine the lateral extent to 

be considered. Unless otherwise noted, throughout this process the source is treated as omni-directional 

and the only animal depth that is considered is the TL target depth that is closest to the source depth 

(placing source and receiver at the same depth is generally an optimal TL geometry). 

The first step is to determine the exposure range (R MAX ) for a single ping. The exposure range in this case 

is the maximum range at which the transmission loss is less than the FOM. Next the source is moved 

along a straight-line track and energy is accumulated at a point that has a CPA range of R MAX at the midpoint 

of the source track. That total energy is then compared to the prescribed threshold. If it is greater 

than the threshold (which, for the first R MAX , it must be) then R MAX is increased by 10 percent, the 

accumulation process is repeated, and the total energy is again compared to the threshold. This continues 

until R MAX grows large enough to ensure that the accumulated energy at that lateral range is less than the 

threshold. The lateral range dimension of the volumetric grid is then set at twice R MAX , with the grid 

centered along the source track. In the nominal direction of advance of the source, the volumetric grid 

extends of the interval from [–R MAX , 3 R MAX ] with the first source position located at zero in this 

dimension. Figure B-4 depicts this geometry. Note that the source motion in this direction is limited to 

the interval [0, 2 R MAX ]. Once the source reaches 2R MAX in this direction, the incremental volume 

contributions have approximately reached their asymptotic limit and further pings add essentially the 

same amount. 

Once the extent of the grid is established, the grid sampling can be defined. In the both dimensions of the 

horizontal plane the sampling rate is approximately R MAX /100. The round-off error associated with this 

sampling rate is roughly equivalent to the error in a numerical integration to determine the area of a circle 

with a radius of R MAX with a partitioning rate of R MAX /100 (approximately 1 percent). The depthsampling 

rate of the grid is comparable to the sampling rates in the horizontal plane but discretized to 

match an actual TL sampling depth. The depth-sampling rate is also limited to no more than 40 meters in 

order to ensure that significant TL variability over depth is captured. 

B.4.3 Exposure Volume by Depth 

After creating the TL field required for a province, energy contributions from each ping location (every 

vp meters) are accumulated at each point in the grid. At the completion of the energy accumulation, there 

are a certain number of grid points that contain an accumulated energy level higher than threshold. Since 

these grid points are uniformly spaced, each one represents a uniform volume of water that is exposed to 

an energy level that is beyond the threshold. These points then could be summed after a certain number 

of pings and multiplied by the volume of water they represent to get the total volume ensonified beyond 

the threshold limit, but the data gives more useful information if it is processed more carefully. 

To deal responsibly with the variation in depth distribution of animals, exposure volume must be summed 

by depth increment. So although total exposure volume is known, it is also known how much of that 


Appendix B 

volume falls between each of the depth intervals. This allows the volume ensonification to be applied to 

each animal's depth-dependent habitat. 

Lateral Direction 

R max 

–R max 3 R max 

Direction of 

Advance 

–R max 

Limit of Energy Grid in 

Horizontal Plane 

Figure B-4. Horizontal Plane of Volumetric Grid for Omni Directional Source 

B.4.4 Exposure by Hour 

As long as the source travels at the same speed, ping at the same rate, and remain in the same province, it 

will expose the same volume in 1 hour as in another beyond some initial time. This approximate linearity 

of exposure volume in time can be seen in the plot of exposure volume as a function of number of pings 

(e.g., Figure B-5). 


Appendix B 

18 x 109 Number of Pings 

16 

14 

Ensonified Volume (cub. m) 

12 

10 

8 

6 

4 

2 

0 

0 100 200 300 400 500 600 700 800 900 1000 

Figure B-5. 190 dB Exposure Volume by Ping at Surface in USWEX Province 8 

The slope of the exposure volume versus number of pings at a given depth provides the exposure volume 

added per ping. This number multiplied by the number of pings in an hour gives the hourly exposure 

volume for the given depth increment. Completing this calculation for all depths in a province gives the 

hourly exposure volume vector, v 

n , which contains the hourly volumes by depth for province n. Figure 

B-6 is a visual representation of v 

8 for USWEX. 

0 

500 

1000 

1500 

2000 

Depth 

2500 

3000 

3500 

4000 

4500 

5000 

0 2 4 6 8 10 12 14 16 18 

Hourly Volume 

x 10 9 

Figure B-6. 190 dB Hourly Volume by Depth for USWEX Province 8 


Appendix B 

B.4.4 Exposure by Modeling Area 

Since the USWEX modeling areas are linear combinations of the eight environmental provinces, the 

hourly exposure volume for a modeling area is a linear combination of { v 

1, 

v2, 

v3, 

v4 

, v5, 

v6 

, v7 

, v8} 

, with 

the same weighting. For example, modeling area 1 is made up of 1.6% province 1, 2.0% province 2, 

7.7% province 3, 16.4% province 4, 40.8% province 5, 0% province 6, 0.9% province 7, and 30.6% 

province 8. Therefore, the modeling area 1 hourly exposure volume vector, 

S = . + v . 

1 

016v1 

+ .02v2 

+ .077v3 

+ .164v4 

+ .408v5 

+ .009v7 

. 306 

An hourly volume vector is produced for USWEX in this way for each of the six modeling areas in 

summer and winter. 

B.5 ANIMALS 

Marine mammal distributions are three-dimensional. That is, each latitude, longitude, and depth point has 

an associated animal density (number of animals per unit volume). The depth component of animal 

distribution is too important to ignore. Figure B-6 (above), illustrates the extreme depth variability of 

impact volume. An animal that spends most of its time at the surface will receive a great deal more 

energy than one that spends most of its time at 1,000 meters. However, most density estimates only give 

densities in two dimensions (animals per sq km), without differentiating deep-diving animals from 

shallow-habitat animals. Turning these two-dimensional densities into three dimensions requires the 

animal depth distributions and a little arithmetic. 

B.5.1 Two-Dimensional Density Estimates 

One important aspect in the evaluation of potential effects to marine mammals in any given area is an 

understanding of the distribution and abundance of the mammals within that geographic area. For 

purposes of this modeling effort, the density estimates from Barlow and Mobley were used. (“Cetacean 

abundance in Hawaiian waters during summer/fall of 2002”, [Barlow, 2003] and “Distribution and 

abundance of odontocete species in Hawaiian waters: Preliminary results of 1993-98 aerial surveys” 

[Mobley et al., 2000]; and “Abundance of humpback whales in Hawaiian waters: Results of 1993-2000 

aerial surveys” [Mobley, 2001]) 

The density estimates are spatially different. The Mobley densities are applicable for areas within 25 

nautical miles (nm) of land, and the densities from Barlow are appropriate for areas beyond 25 nm. To 

determine how to use the different densities, each USWEX ASW modeling area was examined to 

determine what percentage of the area was within 25 nm of land. This was accomplished by using 

Nobeltec, a commercial visual navigational tool. The location of each USWEX ASW modeling area was 

placed on a map overlay. Circles with 25 nm radii were drawn from locations on the closest landmasses. 

The percentage of the USWEX ASW modeling area within 25 nm of land was calculated. In the final 

calculation of the exposure estimates the densities were applied with the same percentages. For example, 

in USWEX ASW modeling area 1, 10.3% of the area is within 25 nm of land. In calculating the 

harassment area for rough-toothed dolphin, 10.3% of the harassment area used the density from Mobley 

and the remaining 89.7% of area used the density from Barlow. 

8 


Appendix B 

B.5.2 Animal Depth 

Animal depth distribution data was not available for the USWEX impact analysis, but the depth of each 

animal’s habitat (defined by maximum depth) was determined by a careful study of many sources, 

especially the Environmental Impact Statement (EIS) for the North Pacific Acoustic Laboratory (NPAL). 

The USWEX animal depths and their sources are listed in Table B-2. 

B.5.3 Uniform Distribution of Animals 

For acoustic impact modeling, two-dimensional animal densities are considered uniform over area. For 

example in USWEX, each modeling area has a single two-dimensional density for each animal. This is 

an approximation to reality based on the available data. If there was data available to accurately 

document the variation of animal densities within each modeling area, it could be included in an impact 

analysis. Likewise, with depth distribution, the available data only reveals animal depth habitat, that is, 

the deepest a species generally dives. Within this depth regime, animal density is assumed uniform with 

depth, and a single number used to approximate a species' distribution in the water column. 

B.5.4 Three-Dimensional Densities 

Assigning an animal the two-dimensional density d means that for every square kilometer of ocean d of 

those animals are expected to be somewhere below that ocean square at any given time. Converting 

densities to three dimensions gives the expected number of animals at each depth below that ocean 

square. The depth-variability of ensonification makes it necessary to replace the ambiguity of the twodimensional 

density (i.e., “somewhere below the ocean square”) with the rigor of three-dimensional 

density. For the USWEX process, the hourly volume vectors are calculated in cubic meters, so the 

densities were calculated with the same units. First, this requires dividing the two-dimensional densities 

by 10 6 , because there are 10 6 square meters in a square kilometer. Next, the animals per square meter is 

divided by the depth of that animal. For example, if an animal’s habitat is the first 500 meters of water 

and that animal's two-dimensional density is 1 per square meter (this is a hypothetical case), then we 

expect 1/500 animals in each of the first 500 meters of water, and zero below that. Real animal numbers 

are much smaller, so for a real USWEX case, sperm whales in modeling area 6, the Barlow-Mobley 

blended density is 

animals animals 

.0029 . 0000000029 

2 = 

2 

km 

m 

The NPAL EIS puts sperm whales habitat depth at 2,000 meters, so the sperm whale three-dimensional 

density for modeling area 6 is 

.0000000029 animals 

= 1.45× 

10 

3 

2000 m 

for each cubic meter in their habitat, and zero below. 

−12 

animals 

3 

m 

All animals of interest in the USWEX environment can hear the AN/SQS-53C. 


Appendix B 

Table B-2. USWEX Animal Depths and References 

Animal 

Depth Reference/Rationale 

NPAL 

(meters) 

pygmy sperm whale 1,000 Feed on cephalopods and crustaceans that are generally deep water dwellers; may feed near no data 

ocean bottom (Reeves et al., 2002) 

dwarf sperm whale 1,000 Feed on cephalopods and crustaceans that are generally deep water dwellers; may feed near no data 

ocean bottom (Reeves et al., 2002) 

*sperm whale 2,000 Taken from North Pacific Acoustic Laboratory (NPAL) (NOTE: Jefferson et al. (1993) has 2,000 

them as deep as 3,200 meters) 

rough-toothed dolphin 300 Taken from NPAL 300 

bottlenose dolphin 525 Reeves et al., 2003 indicates dive to depths of more than 500 m based on presence of deepsea 

535 

fish in stomach contents 

Fraser’s dolphin 500 Moderate depth assigned based on mixed diet of cephalopods, fish, crustaceans no data 

spotted dolphin 500 Moderate depth assigned based on mixed diet of cephalopods, fish, crustaceans 300 

striped dolphin 500 Moderate depth assigned based on mixed diet of cephalopods, fish, crustaceans no data 

spinner dolphin 500 Moderate depth assigned based on mixed diet of cephalopods, fish, crustaceans 535 

short-finned pilot whale 800 Baird et al., 2003 610 

melon-headed whale 1,000 Reeves et al., 2003 indicates that prey organisms are in water up to 1,500 meters deep, and 1,500 

it is thought that they feed fairly deep in the water column, but apparently not at the bottom 

Risso’s dolphin 750 Based on foraging patterns which are primarily squid no data 

Cuvier’s beaked whale 1,450 Baird et al., 2005 1,000 

Blainville’s beaked whale 1,408 Baird et al., 2005 1,000 

Longman’s beaked whale 1,400 Extrapolated from measured depths of Cuvier's and Blainville's beaked whales as provided 1,000 

in Baird et al. (2005) 

pygmy killer whale 265 Extrapolated from NPAL number for killer whale no data 

killer whale 265 Taken from NPAL 265 

false killer whale 265 Extrapolated from NPAL number for killer whale same as killer 

humpback whale 50 Humpback whale recovery plan (1991)—“cows with calves appear to preferentially use 

leeward nearshore waters within the 10 fathom isobath”; Baird et al. (2000)—85% of time 

spent in water 0-50 meters (Table 3) 

no data 


Appendix B 

B.6 CALCULATING EXPOSURES 

In B.4, a vector of hourly impact volume by depth for each modeling area in summer and winter was 

made, for a total of 12 (six modeling areas by two seasons). The animal densities do not change by 

season, except the humpbacks, which go to zero in the summer. Impact volume can be converted into 

exposures by multiplying by the number of animals expected to be in a unit of that volume. For USWEX, 

this means multiplying all elements of the impact volume vector that fall in a certain animal's depth 

habitat by that animal's three-dimensional density and summing them. For example, the sperm whale's 

−12 

animals 

depth habitat is 0-2,000 meters, and its density in that habitat is 1.45× 10 

. Operating for 1 

3 

m 

10 

hour in modeling area 6 ensonifies 1 .2089× 10 cubic meters of water within 2,000 meters of the surface 

to an accumulated energy level of 190 dB or more. Thus the hourly sperm whale exposure count for 

winter modeling area 6 is 

1.45× 

10 

−12 

animals 

⋅1.2089× 

10 

3 

m 

10 

3 

m 

≈ .0175 animals per hour. 

hr 

The hourly exposure count allows flexibility in allocating sonar hours between operations. The hours 

given in Table B-1 for each modeling area were multiplied, by season, by the hourly exposure rates for 

each animal, modeling area, and season in a series of spreadsheets in order to calculate the number of 

exposures. 


Appendix B 

REFERENCES 

Baird, R.W., A.D. Ligon and S.K. Hooker, 2000. Sub-surface and night-time behavior of humpback 

whales off Maui, Hawaii: a Preliminary Report. Report under contract #40ABNC050729 from 

the Hawaiian Islands Humpback Whale National Marine Sanctuary, Kihei, HI to the Hawaii 

Wildlife Fund, Paia, HI. 

Baird, R.W., D.J. McSweeney, M.R. Heithaus and G.J. Marshall, 2003. Short-finned pilot whale diving 

behavior: deep feeders and day-time socialites. Abstract submitted to the 15th Biennial 

Conference on the Biology of Marine Mammals, Greensboro, NC, December 2003. 

Baird, R.W., 2005. Sightings of Dwarf (Kogia sima) and Pygmy (K. breviceps) Sperm Whales from the 

Main Hawaiian Islands. Pacific Science 59(3):461-466. 

Barlow, J., 2003. “Cetacean Abundance in Hawaiian Waters During Summer/Fall of 2002”, PSRG-7, 

National Oceanic and Atmospheric Administration, NOAA Fisheries, Southwest Fisheries 

Science Center, La Jolla, CA, p. 20. 

Cembrola, J. and Deavenport, R., 2005. “Marine Mammal Acoustic Effect Modeling Conducted for 

RIMPAC 06.” Naval Undersea Warfare Center, Newport. 

Jefferson, T.A., S. Leatherwood and M.A. Webber, 1993. Marine mammals of the world. FAO Species 

Identification Guide. United Nations Environment Programme, Food and Agriculture 

Organization of the United Nations. 

Keenan, R.E., et al., 2000. “Software Design Description for the Comprehensive Acoustic System 

Simulation (CASS Version 3.0) with the Gaussian Ray Bundle Model (GRAB Version 2.0)”, 

NUWC-NPT Technical Document 11,231, Naval Undersea Warfare Center Division, Newport, 

RI, 1 June (UNCLASSIFIED). 

Mobley, J.R., Jr., S.S. Spitz, K.A. Forney, R.A. Grotefendt, and P.H. Forestell, 2000. “Distribution and 

Abundance of Odontocete Species in Hawaiian Waters: Preliminary Results of 1993-98 Aerial 

Surveys”, SFSC Administrative Report LJ-00-14C, NOAA Fisheries, Southwest Fisheries 

Science Center, p. 26. 

Mobley, J.R., S.S. Spitz, R.A. Grotefendt, P.H. Forestell, A.S. Frankel, and G.B. Bauer, 2001. Abundance 

of Humpback Whales in Hawaiian Waters: Results of 1993-2000 Aerial Surveys. Report to the 

Hawaiian Islands Humpback Whale National Marine Sanctuary. 

National Marine Fisheries Service, 1991. “Recovery Plan for the Humpback Whale (Megaptera 

novaeangliae).” Prepared by the Humpback Whale Recovery Team for the National Marine 

Fisheries Service. Silver Spring, MD. 

Reeves, R.R., B.S. Stewart, P.J. Clapham, and J.A. Powell, 2002. National Audubon Society Guide to 

Marine Mammals of the World. Alfred A Knopf: New York. 


Appendix B 



Appendix C 

2006 Rim of the Pacific Exercise 

After Action Report: 

Analysis of the Effectiveness of the 

Mitigation and Monitoring Measures as 

Required Under the Marine Mammal 

Protection Act (MMPA) Incidental 

Harassment Authorization and National 

Defense Exemption from the Requirements 

of the MMPA for Mid-Frequency Active 

Sonar Mitigation Measures 

Dated December 7, 2006 

October 2007 USWEX EA/OEA C-1

Appendix C 


C-2 USWEX EA/OEA October 2007

Appendix C 

INTRODUCTION 

This report is presented to fulfill the requirements conditional to the 2006 Rim of the 

Pacific Exercise (RIMPAC 06) Marine Mammal Protection Act (MMPA) Incidental 

Harassment Authorization (IHA) and the National Defense Exemption from the 

Requirements of the MMPA for Certain DoD Mid-Frequency Active Sonar Activities 

(NDE). 

Pursuant to the MMPA, an IHA was sought from the National Marine Fisheries Service 

(NMFS), which was issued by the NMFS Division of Permits, Conservation, and 

Education, Office of Protected Resources for 2006 RIMPAC Exercise on 27 June 2006. 

On 30 June 2006, the Deputy Secretary of Defense issued the NDE, which specified that 

for the conduct of RIMPAC 2006, the Navy would comply with all mitigation measures 

set out in the IHA. The IHA required that the Navy, “Submit a report to the Division of 

Permits, Conservation, and Education, Office of Protected Resources, NMFS and the 

Pacific Islands Regional Office, NMFS, within 90 days of the completion of RIMPAC.” 1 

The IHA further specifies that the report contain and summarize the following 

information: 

(1) “An estimate of the number of marine mammals affected by the RIMPAC ASW 

exercises and a discussion of the nature of the effects, if observed, based on both the 

modeled results of real-time exercises and sightings of marine mammals”; 

(2) “An assessment of the effectiveness of the mitigation and monitoring measures 

with recommendations on how to improve them”; 

(3) "Results of the marine species monitoring (real-time monitoring from all 

platforms, independent aerial monitoring, shore-based monitoring at chokepoints, 

etc.) before, during, and after the RIMPAC exercises”; and 

(4) "As much information (unclassified and, to appropriately cleared recipients, 

classified “secret”) as the Navy can provide including, but not limited to, where and 

when sonar was used (including sources not considered in take estimates, such as 

submarine and aircraft sonars) in relation to any measures received levels (such as 

sonobuoys or on PMRF range), source levels, numbers of sources, and frequencies 

so it can be coordinated with observed cetacean behaviors." 

This report, which contains only unclassified material, provides the necessary 

information and analyses, and thus fulfills these requirements. The report is organized by 

section following the order of the requirements in the IHA. 

Section 1 provides an estimated number of marine mammals affected by the RIMPAC 06 

ASW events based on analysis of actual events and sightings of marine mammals, noting 

the nature of any observed effects where possible. 

1 Given that the last day of the RIMPAC 2006 exercise was 26 July 2006, this report is due no later than 24 October 2006. 

October 2007 USWEX EA/OEA C-3 

1

Appendix C 

Section 2 of this report assesses the effectiveness of the mitigation and monitoring 

measures required during RIMPAC 2006 with regard to minimizing the use of 

Mid-Frequency Active Sonar (MFAS) in the vicinity of marine mammals. This section 

also includes an assessment of the practicality of implementation of the mitigation 

measures, the scientific basis behind those measures, and the impact some of the 

measures had on safety and the effectiveness of the required military readiness activities. 

Section 3 presents the results of the marine species monitoring comprised of independent 

aerial reconnaissance, shore-based monitoring in the vicinity of the chokepoint events, 

and results from the NMFS observers embarked on the USS LINCOLN during one of the 

choke-point exercises. Also included in this section is a summary of the 29 marine 

mammal detections made by exercise participants during RIMPAC 06. 

Section 4 of this report provides data on the location and hours of active MFAS used 

during RIMPAC 06 placed in context with observations of cetacean behaviors resulting 

from the aerial reconnaissance and shore-based monitoring and exercise participants. 

C-4 USWEX EA/OEA October 2007 

2

Appendix C 

SECTION 1: Marine Mammals Affected 

The requirements stipulated in the IHA are to provide; “An estimate of the number of 

marine mammals affected by the RIMPAC ASW exercises and a discussion of the nature 

of the effects, if observed, based on both the modeled results of real-time exercises and 

sightings of marine mammals”. To meet this requirement, Section 1 provides an 

estimated number of marine mammals affected by the RIMPAC 06 ASW events based on 

Navy’s original calculations using a threshold of 190dB for sub-TTS effects, and analysis 

of actual events and sightings of marine mammals, noting the nature of any observed 

effects. It is compared to the estimated number of marine mammals affected as 

calculated when applying the 173dB sub-TTS threshold required by NMFS for issuance 

of the IHA. 

The RIMPAC 2006 Supplemental Environmental Assessment predicted 532 hours of hull 

mounted MFAS use by exercise participants based on what had occurred in the previous 

RIMPAC exercise (RIMPAC 2004) and based on the present tactical ASW training 

requirements. In actuality, 472 hours of MFAS use from hull mounted sources occurred 

during RIMPAC 06 exercise. 2 

The types of ASW training conducted during RIMPAC 06 involved the use of ships, 

submarines, aircraft, non-explosive exercise weapons, and other training related devices. 

While ASW events would occur throughout the Hawaiian Islands Operating Area, most 

events would occur within six areas that were used for the modeling analysis since they 

were representative of variation in the marine mammal habitats and the bathymetric, 

seabed, wind speed, and sound velocity profile conditions within the entire Hawaiian 

Islands Operating Area (OPAREA). Figure 1 on the following page displays the areas 

used for modeling and the OPAREA for the RIMPAC 06 exercise. 

For purposes of the impacts analysis, all likely RIMPAC 06 ASW events were modeled 

as occurring in these areas. In fact, the majority of MFAS use occurred in the modeled 

areas as predicted (see Section 4 for a more detailed discussion), but any deviation from 

this would have been immaterial since the modeled areas were delineated so as to 

encompass the variation occurring in the entire Hawaiian Islands Operating Area. 

Modeling a predicted number of marine mammals affected by the RIMPAC 06 ASW 

events was undertaken based on acoustic thresholds derived from experimental data – 

190 dB Sound Exposure Level (SEL), which Navy believed, in a worst case analysis, 

indicated the potential to affect 289 marine mammals (for further details see the 2006 

Supplement to the 2002 Rim of the Pacific Programmatic Environmental Assessment). 

This number was calculated from the modeling without consideration for reductions 

resulting from the standard Navy protective measures mitigating exposure to MFAS or 

the additional measures imposed by the IHA. 

2 Three days of planned MFAS use were precluded by a temporary restraining order resulting from a lawsuit. 


3

Appendix C 

Figure 1. RIMPAC 2006 Exercise Operating Area depicting the areas used for modeling 

purposes in the analysis of effects on marine mammals. 


4

Appendix C 

Based on the reduction of MFAS hours from the modeled 532 to the actual 472 hours, the 

estimated potential number of marine mammals affected may be reduced to 

approximately 256 marine mammals (based on a ratio of marine mammal exposures 

exceeding the threshold to hours of MFAS operation). 

Following the modeled calculation of marine mammals affected, if required to determine 

the actual number of marine mammals affected by the exercise as mandated by the IHA, 

it is necessary to take into consideration standard Navy protective measures including 

decreasing the source level and then shutting down MFAS when detected marine 

mammals are approached. This must be done since the mitigative effect of the protective 

measures were not factored into the modeling calculations. While there is no clear metric 

value that can be assigned to mitigative effect of these measures, there was a reduction in 

potential to impact marine mammals by their implementation. 

During the exercise, there were 29 instances when marine mammals (individuals or pods) 

were detected by exercise participants. All detections were made by standard lookout 

and aircraft reporting procedures except for one case of passive acoustic detection, which 

is also a standard Navy practice protective measure. As a result of the protective 

measures in place and the high-level emphasis placed upon marine mammal protection, 

MFAS was shutdown by 12 exercise participants due to the detected marine mammals as 

detailed in Table 1. 

Table 1. Details of the 29 marine mammal detections and actions by exercise participants 

during RIMPAC 06. 

1 

July Date- 

Time (Z) 

Modeled 

Area (Fig. 1) 

Lost 

Hours 

7/10-1738 1 0.5 

Description of Actions Taken 

Helicopter sighted “marine mammal” >30Kyds from two active ships. 

Two ships shutdown MFAS for 15 min until further information from 

reporting unit was obtained and assessed in regard to requirements. 

Submarines in vicinity. 

Surface ship sighted “marine mammal” and shutdown MFAS. Other 

Surface Action Group (SAG) units notified. Helicopter obtained visual 

on “a whale”; notified nearest ship in SAG. Second helicopter 11 nm 

west detected another “whale” four minutes later but contact then 

2 

immediately lost on both whales. Ship in SAG obtained visual on “pod 

7/10-1912 5 1.5 of dolphins”, which then approached w/in 1000 yards so MFAS 

reduced sonar by 6 dB. Second pod of dolphins appeared soon 

thereafter and then a third “whale” appeared inside 200 yards MFAS 

shutdown for all three 3 SAG surface and 2 air units 30 min. MFAS 

resumed 30 minutes later after range opened. Submarine in vicinity. 

Note: 6 total marine mammal detections this event. 

3 7/11-1314 2 Surface ship sighted “dolphin” at 500 yds. MFAS not active. 

4 

Surface ship sighted “pod of whales” range at 300 yds. Maneuvered to 

7/11-1522 2 

open range. MFAS not active. 

5 7/11-1641 2 Surface ship sighted “whale” at 200 yds. MFAS not active. 

Sighted “marine mammal” and shutdown MFAS opened range prior to 

7/12 0215 2 0.5 

6 

recommencing active. 


5

Appendix C 

Table 1 (cont.). Details of marine mammal detections and actions by exercise 

participants during RIMPAC 06 

Modeled Lost 

Area (Fig. 1) Hours 

Description of Actions Taken 

July Date- 

Time (Z) 

7 7/12-1827 5 2.0 

P-3 aircraft detected passive acoustic marine mammal traces within 

4000 yards. Active tracking of submarine ceased with limitation to 

passive only and lost contact. Four submarines in vicinity. 

8 7/14-1909 1 Ship sighted “whale” >1000 yards. MFAS remained active. 

9 7/14-1923 1 Ship sighted “marine mammal” >1000 yards. MFAS remained active. 

10 7/17-1625 1 Ship sighted a “dolphin”. MFAS not active. 

11 7/17 2248 2 0.5 

P-3 aircraft sighted two “whales”. Could not use active (DICASS) 

buoys. Submarine in vicinity. 

12 

13 

7/19 0046 1 0.25 Ship sighted “2 pods of 10 pilot whales”. Shutdown MFAS. 

7/19 0320 1 0.5 

Ship sighted “pod of three pilot whales” to the south bearing 040T 

@200 yds. Shutdown MFAS. 

14 7/19 1819 2 0.25 Ship sighted “whales” 1000 yards off port beam. Shutdown MFAS. 

15 

16 

17 

18 

7/20 0346 5 1.0 Ship sighted “pod of whales”. Shutdown MFAS. 

7/20 1612 2 0.5 

Ship sighted “marine mammals”. Shutdown MFAS. Submarine in 

vicinity. 

7/20 2013 6 Ship sighted “dolphins” off bow. MFAS not active. 

7/20 2128 6 

P-3 aircraft sighting of 8 “whales”. DICASS not available for tactical 

development. Submarine in immediate vicinity. 

19 7/20 2300 5 

20 7/21 1742 5 

Ship sighted 5 “dolphins” moving SE at 8 kts. MFAS not active Two 

submarines in vicinity. 

Ship sighted pod of approx 20 “dolphins” moving to SE. MFAS not 

active. Two submarines in vicinity. 

21 7/22 0429 5 

Ship sighted “porpoises” 1-2 miles off starboard beam. MFAS not 

active. Two submarines in vicinity. 

22 

7/23 0457 3 Ship sighted “pilot whale”. MFAS not active. 

23 7/23 1913 5 0.5 

24 7/25 0015 4 

Ship sighted 20 “whales” heading SW and shutdown MFAS. Two 

submarines in the area. 

NMFS passed along report of pod of approx 400-500 melon-headed 

whales in channel between Maui and Hawaii. P-3 tasked to investigate 

but verification precluded due to cloud cover. 

25 

7/25 0430 5 Ship sighted “whale”. MFAS not active. 

Participant 

Hours Lost 

8.0 


6

Appendix C 

As noted previously, instances of marine mammal detection by exercise participants with 

the resulting implementation of protective measures was unaccounted for by the 

predictive modeling assessing potential exercise effects on marine mammals. In 

RIMPAC 06, there were 29 marine mammal detections by exercise participants, which 

resulted in protective measures being implemented for approximately 70 marine 

mammals and eight additional “pods” of marine mammals (Table 1). Assuming that each 

detected (un-quantified) pod of marine mammals consisted of at least four marine 

mammals, then the total number of detected marine mammals for which exposure to 

MFAS was limited by standard Navy lookouts was approximately 100 marine mammals. 

Also required for the analysis in this section was consideration of “the nature of any 

observed effects” resulting from MFAS use. The reports from exercise participants 

contained nothing that could be construed as abnormal or “observed effects” of MFAS. 

There were no instances where marine mammals behaved in an erratic, unusual, or 

anything other than a normal manner. 

Details regarding sightings and behaviors resulting from the aerial reconnaissance and the 

shore-based observers are presented in Section 3 of this report. In short, there were no 

abnormal behaviors or unusual distributions of marine mammals observed during these 

monitoring efforts and, therefore, no observed effects resulting from MFAS use. 

Of the estimated potential 256 marine mammals affected by 472 hours of MFAS use, 

approximately 100 were precluded from exposure to MFAS by implementation of the 

protective measures. Therefore, an estimate of the number of marine mammals affected 

by the RIMPAC ASW exercises was 156 marine mammals based on the modeled results 

of real-time exercises, actual events, and sightings. 

NMFS believed that the 190dB SEL sub-TTS threshold was not sufficiently 

precautionary and required Navy to apply for its IHA using 173dB SEL. Using the 

173dB threshold with the same modeling program and marine mammal density estimates 

as before, we arrived at in excess of 33,000 behavioral disturbances, or takes. For 

perspective, this is about twice the number of marine mammals estimated to inhabit the 

waters around Hawaii in which the exercise took place. 

There were no affected marine mammals observed by exercise participants, aerial or 

shore based monitors, or via any other reports. Therefore, further analysis based on 

observed effects, as mandated by this reporting requirement, is not possible and was not 

attempted. 

In summary, the pre-exercise estimate of marine mammals behaviorally affected in 

RIMPAC 06 was 289 using 190dB sub-TTS threshold and over 33,000 using 173dB. No 

observers, from any platform or vantage point, noted in any reports that any marine 

mammals were affected by sonar. Conclusions are: 

- Using 173dB SEL, a discrete decibel level, to define sub-TTS threshold was overly 

precautionary to a significant degree. 


7

Appendix C 

- There was no evidence of any behavioral affects on marine mammals throughout the 

exercise. 


8

Appendix C 

SECTION 2: Mitigation And Monitoring 

As required under the IHA the report must contain, “An assessment of the effectiveness 

of the mitigation and monitoring measures with recommendations on how to improve 

them”. This section of the report, therefore, provides an assessment of the effectiveness 

of the mitigation and monitoring measures, the scientific validity behind each measure, 

and recommendations on how to improve them with regard to practicality of 

implementation, their impact on exercise safety, and their impact on the effectiveness of 

the military readiness training activity. 

During RIMPAC 06, there were 199 anti-submarine warfare (ASW) events and 472 total 

hours of mid-frequency active sonar (MFAS) use. There were no reported stranding 

events or observations of behavioral disturbance of marine mammals linked to sonar use 

during the exercise. Specifically, there were three monitored choke-point exercises with 

observations by aerial reconnaissance and shore-based monitors before, during, and after. 

There was no indication from the Navy monitors or from the non-governmental civilian 

monitors of any effects on marine mammals. These results are consistent with the 

previous 19 RIMPAC exercises in which no strandings linked to sonar use. 

The only mitigation measures that prevented the use of MFAS in the vicinity of marine 

mammals were those that the Navy already had in place (Lookouts, aircraft reporting, and 

“safety zones”) with the exception of a modification of the Navy’s safety zone (450 yds) 

to 1000 m, agreed to for issuance of the IHA. The result of applying these standard 

mitigation measures was that exercise participants lost approximately eight hours of 

active sonar use. 

In the 12 events where MFAS was shutdown by exercise participants, a total of 

approximately eight hours of ongoing MFAS use ceased, thus impacting the effectiveness 

of those military readiness activities. Some of the interrupted events involved lost time 

by multiple units operating in an integrated manner with the ramification being that 

shutdown of MFAS by a Surface Action Group (SAG) consisting of three vessels for 30 

minutes resulted in 1.5 hours lost training time. Many of these events took place when 

submarines were in the vicinity of exercise participants and could have possibly been 

detected if MFAS had been available. It is important to realize that for the remainder of 

the instances for which marine mammals were detected, the option to use MFAS as 

tactically indicated was precluded and thus impacted the effectiveness of exercise event 

since commanders were operating without the option of their full sensor suite (e.g., 

helicopters operating with the SAG). This is especially true in the case of events 

involving sonobuoys where the inability to command-activate DICASS may have 

precluded the ability to track a contact or precluded development of attack criteria. In 

one case during RIMPAC 06 (Table 1, #7), a P-3 aircraft lost track on a submarine 

actively being prosecuted resulting in a major training impact to the unit involved. 


9

Appendix C 

ASW proceeds slowly and requires careful development of a tactical frame of reference 

over time as data is integrated from a number of sources and sensors. Once MFAS is 

turned off for a period of time, simply turning it back on minutes later does not usually 

allow a Commander to simply continue from the last frame of reference. Thus, 15 

minutes of lost MFAS time does not equate to only 15 minutes of lost exercise time but 

should be considered in the fuller context of its overall impact on the tempo and tactical 

development of a Common Operational Picture shared among exercise participants as 

they trained with the goal of interoperability and improvement of ASW skills in general. 

While the Navy’s standard protective measures impacted the effectiveness of the training, 

a subset of the additional measures imposed by the IHA had no observed increased 

effectiveness in the protection of mammals during this exercise, and restricted the ability 

to train realistically in the known diesel submarine threat environments required for 

warfighting readiness. This subset of mitigation measures is as follows: 

• Requirements regarding “strong surface ducting conditions” 

• Requirements regarding “low visibility conditions” 

• Restrictions from operating MFAS within 25 km of the 200 m isobath. 

• Restrictions from operating MFAS in choke-points, constricted channels or 

canyon-like areas. 

The following requirements associated with choke-point events were monitoring efforts 

mandated by NMFS as a sampling strategy to determine if there was any effect on 

marine mammals during these transits of the channels while conducting ASW 

operations.. 

• Additional requirements when conducting choke-point operations, to include: 

• Additional Non-Navy observers 

• Extensive additional aircraft monitoring 

• Shoreline reconnaissance 

• Additional Navy lookouts 

These measures arose from a precautionary concern that MFAS use in the channels could 

possibly have greater potential to impact marine mammals, despite no evidence 

suggestive of this from previous RIMPAC exercises. The cost to implement these 

requirements was $66,000 for RIMPAC 06. 

Analysis of results from RIMPAC indicates that the types of measures already in place in 

the Protective Measures Assessment Protocol (PMAP) were adequate to prevent 

operation of MFAS in the vicinity of detected marine mammals: 

• There were no indications of any effects to any marine species throughout the 

exercise. 

• Of the 29 instances where marine mammals were detected, MFAS was shutdown 

for 12 units and ASW events were interrupted by implementation of standard 

mitigation measures by Navy watch standers or aircraft (see Table 1). Mitigation 


10

Appendix C 

measures agreed to for this exercise that were in addition to Navy SOP protective 

measures did not provide observable increased protection to marine mammals. 

• Burdensome administration of the IHA’s additional mitigation measures 

distracted exercise participants, watchstanders, and exercise commanders at the 

headquarters level from their primary responsibility of exercise training and 

safety. While personnel seemed to adequately absorb this increased workload, 

there were no indications from all observations that the additional mitigation 

measures required provided additional protection to marine mammals during this 

exercise. 

The following protective measures were already Navy SOP (PMAP) and were also 

mandated as mitigation measures for RIMPAC: 

1. Personnel are trained on marine mammal awareness and mitigation measures. 

2. There are personnel on lookout with binoculars at all times when the vessel is 

moving through the water. 

3. On surface ships there are always at least three people on the bridge on lookout at 

all times and during ASW operations at least five people on lookout. 

4. Lookouts report the sighting of any marine species, disturbance to the water's 

surface, or object in the water to the Officer of the Deck, who is the Commanding 

Officer’s direct representative on watch. 

5. A safety zone is established around an active sonar source and sonar power is 

reduced when marine mammals enter this zone. 

6. Submarine sonar operators review detection indicators of close-aboard marine 

mammals prior to the commencement of ASW operations involving MFAS. 

7. Aerial surveillance for marine species occurs whenever possible and detections 

are reported to ships in the vicinity. 

8. Helicopters using active (dipping) sonar observe and employ a safety zone. 

9. Sonar is always operated at the lowest practicable level to meet tactical training 

objectives. 

The following mitigation measures agreed to for issuance of the IHA had no observable 

impact on the protection of mammals in this exercise and negatively affected training. 

Prohibitions against operating in shallow water or in choke-points are contrary to ASW 

training requirements. These measures affect the ability to train realistically in the known 

diesel submarine threat environment and directly impact vital military readiness activity: 

1. The restriction from operating MFAS within 25 km of the 200 m isobath. 

2. The restriction from conducting sonar activities in constricted channels or canyonlike 

areas. 

The following measures had no observable effect on the protection of mammals during 

this exercise, and could not be accurately and uniformly employed: 

1. Requirements regarding “strong surface ducting conditions” 

2. Requirements regarding “low visibility conditions” 


11

Appendix C 

To organize the assessment of each mitigation measure, they are presented below in the 

order and organization as presented by in the IHA. 

RIMPAC 06 IHA Mitigation and Monitoring Requirements 

Measures (a) and (b) 

The first two mitigation measures ((a) and (b)) detail training requirements for units 

participating in MFAS ASW exercises. All of the requirements within these two 

measures are redundant with the Marine Species Awareness Training (MSAT) that Navy 

lookouts and bridge personnel receive as Navy SOP. MSAT was developed in 

coordination with marine biology experts within the Navy and provides all effective 

marine species detection cues and information necessary to detect marine mammals and 

sea turtles. This material is part of the Navy Lookout watchstander qualification system, 

and will soon be available as online interactive training, and can also be provided in a 

video format for large audience presentations. 

NMFS (Pacific Islands Region) reviewed and approved MSAT to meet the purposes of 

these first two mitigation measures. 

Measure (a) 

The MMPA Permit Monitoring and Mitigation Measure (a) read as follows: 

(a) All RIMPAC participants will receive the following marine mammal 

training/briefing during the port phase of RIMPAC: 

(i) Exercise participants (CO/XO/Ops) will review the C3F Marine 

Mammal Brief, available OPNAV N45 video presentations, and a NOAA 

brief presented by C3F on marine mammal issues in the Hawaiian Islands. 

(ii) NUWC will train observers on marine mammal identification 

observation techniques. 

(iii) Third fleet will brief all participants on marine mammal mitigation 

requirements. 

(iv) Participants will receive video training on marine mammal 

awareness. 

Assessment: Training was already standard for all units before RIMPAC and is 

effective as a mitigation measure. 

Operational Impact of this mitigation measure: 

None. Using standardized and required training materials and procedures is more 

practical and effective. 

Recommendation 

Training personnel in marine species detection and cues to enable operators to make 

informed decisions regarding potential interactions with protected marine species should 

be retained and is standard Navy practice. This measure should be rewritten as provided 

in Appendix (A). 


12

Appendix C 

Measure (b) 

The MMPA Permit Monitoring and Mitigation Measure (b) read as follows: 

(b) Navy watchstanders, the individuals responsible for detecting marine 

mammals in the Navy's standard operating procedures, will participate in marine 

mammal observer training by a NMFS-approved instructor. Training will focus 

on identification cues and behaviors that will assist in the detection of marine 

mammals and the recognition of behaviors potentially indicative of injury or 

stranding. Training will also include information aiding in the avoidance of 

marine mammals and the safe navigation of the vessel, as well as species 

identification review (with a focus on beaked whales and other species most 

susceptible to stranding). At least one individual who has received this training 

will be present, and on watch, at all times during operation of tactical midfrequency 

sonar, on each vessel operating mid-frequency sonar. 

Assessment: Training as a mitigation measure can be captured in one requirement 

as provided in Appendix (A). 


None. Using standardized and required training materials and procedures is more 

practical and effective. 


For Navy authorizations, adopt the training measure provided in Appendix (A), which is 

based on the MSAT training video. 

(1) The Navy’s training and qualification program meets or exceeds the expectations of 

this mitigation measure. Navy personnel serving as lookouts and on bridge watch are 

highly qualified and experienced marine observers. At all times, they are required to 

sight and report all objects sighted in the water (regardless of the distance from the 

vessel) to the Officer of the Deck, because any object (e.g., trash, periscope) or 

disturbance (e.g., surface disturbance, discoloration) in the water may be indicative of a 

threat to the vessel. Navy lookouts undergo extensive training in order to qualify. This 

training includes on-the-job instruction under the supervision of an experienced lookout, 

followed by completion of the Personal Qualification Standard program, certifying that 

they have demonstrated the necessary skills (such as detection and reporting of partially 

submerged objects). In addition to these requirements, many lookouts periodically 

undergo a 2-day refresher training course. 

(2) The Navy includes MSAT as part of its regular training regimen for its bridge 

lookout personnel on ships and submarines. This training is the most appropriate 

material available to allow for the safe operation of Naval vessels while limiting 

interactions with marine mammals and has been approved by NMFS. This training 

addresses the lookout’s role in environmental protection, laws governing the protection of 

marine species, Navy stewardship commitments, and general observation information to 

aid in avoiding interactions with marine mammals. Finally, Navy personnel are trained 


13

Appendix C 

in the most effective means to ensure quick and effective communication within the 

command structure and facilitate implementation of protective measures if marine species 

are spotted. Navy personnel are trained to act swiftly and decisively to ensure that 

information is passed to the appropriate supervisory personnel. 

Measure (c) 

This measure reads: 

(c) All ships and surfaced submarines participating in the RIMPAC ASW 

exercises will have personnel on lookout with binoculars at all times when the 

vessel is moving through the water (or operating sonar). These personnel will 

report the sighting of any marine species, disturbance to the water's surface, or 

object to the Officer in Command. 

Assessment: This measure is included Navy’s SOPs, but as written requires one 

change. 


None. 


This mitigation measure is standard Navy practice and necessary for safe navigation. 

Reference to surfaced submarines should be removed since surfaced submarines are 

never engaged in ASW or use MFAS for ASW when on the surface. 

Measure (d) 


(d) All aircraft participating in RIMPAC ASW events will conduct and 

maintain, whenever possible, surveillance for marine species prior to and during 

the event. Marine mammal sightings will be immediately reported to ships in the 

vicinity of the event as appropriate. 

Assessment: This measure is part of Navy’s SOPs. 


None. 


This mitigation measure is standard Navy practice and necessary for safe navigation. 

Measure (e) 


(e) Submarine sonar operators will review detection indicators of closeaboard 

marine mammals prior to the commencement of ASW operations involving 

active mid-frequency sonar. Marine mammals detected by passive acoustic (sic) 3 

3 The last sentence of this mitigation measure as published in both the IHA and the NDE is incomplete. 


14

Appendix C 

Assessment: This measure is in Navy’s SOPs. 


None. 


These practices are already standard Navy procedures. 

Measure (f) 


(f) Safety Zones - When marine mammals are detected by any means 

(aircraft, lookout, or acoustically) within 1000 m of the sonar dome (the bow), the 

ship or submarine will limit active transmission levels to at least 6 dB below 

normal operating levels. Ships and submarines will continue to limit maximum 

transmission levels by this 6-dB factor until the animal has been seen to leave the 

area, has not been seen for 30 minutes, or the vessel has transited more than 2000 

m beyond the location of the sighting. 

Should a marine mammal be detected within or closing to inside 

500 m of the sonar dome, active sonar transmissions will be limited to at least 10 

dB below the equipment's normal operating level. Ships and submarines will 

continue to limit maximum ping levels by this 10-dB factor until the animal has 

been seen to leave the area, has not been seen for 30 minutes, or the vessel has 

transited more than 1500 m beyond the location of the sighting. 

Should the marine mammal be detected within or closing to inside 

200 m of the sonar dome, active sonar transmissions will cease. Sonar will not 

resume until the animal has been seen to leave the area, has not been seen for 30 

minutes, or the vessel has transited more than 1200 m beyond the location of the 

sighting. 

If the Navy is operating sonar above 235 dB and any of the 

conditions necessitating a power-down arise ((f), (g), or (h)), the Navy shall 

follow the requirements as though they were operating at 235 dB - the normal 

operating level (i.e., the first power-down will be to 229 dB, regardless of at what 

level above 235 sonar was being operated). 

Assessment: This mitigation measure is effective, and requires improvement. 


During RIMPAC, marine mammals were visually detected three times by fixed-wing 

aircraft, three times by helicopters, and 23 times by lookouts aboard ships. Active MFAS 

use ceased in 12 exercise events, as the ships opened the range with the locations where 

the marine mammals had been detected. In three additional events, P-3 aircraft were not 

able to use active DICASS sonobuoys as tactics may have required. Due to this 

mitigation measure, a total of approximately eight hours of training time was lost. 

This loss of MFAS training hours is more than a simple metric involving a loss of 

training time as a small percentage of the overall exercise hours since, in at least six 


15

Appendix C 

cases, the proximity of a submarine in the vicinity meant there was a potential submarine 

detection opportunity missed by the exercise participants. 


A “safety zone” mitigation measure was already SOP and this mitigation measure should 

be retained. Expansion of the safety zone beyond 1000 m (or 1000 yards) is not prudent. 

This distance is the maximum Navy should impose on its ship commanding officers to 

certify “safe” for marine mammals or decrease the output of MFA sonar. 

The provision regarding the reduction of transmission power if operating sonar above 

235 dB is reasonable and should be added as Navy SOP. 

This mitigation measure involving “safety zones” should be retained with the following 

revisions: 

• Yards should be used vice meters because all Navy training and operations 

use yards as a term reference and there is no substantive difference in 

sound propagation between 1000 meters and 1000 yards. 

• The 2000 meter, 1500 meter, and 1200 meter variable distance for when 

active sonar can resume is unnecessarily complex and the expanded 

distances without scientific merit. 

Measure (g) 


(g) In strong surface ducting conditions (defined below), the Navy will 

enlarge the safety zones such that a 6-dB power down will occur if a marine 

mammal enters the zone within a 2000 m radius around the source, a 10-dB 

power-down will occur if an animal enters the 1000 m zone, and shut down will 

occur when an animal closes within 500 m of the sound source. 

A strong surface duct (half-channel at the surface) is defined as having the 

all the following factors: (1) A delta SVP between 0.6 to 2.0 m/s occurring within 

20 fathoms of the surface with a positive gradient (upward refracting); (2) Sea 

conditions no greater than Sea State 3 (Beaufort Number 4); and (3) Daytime 

conditions with no more than 50% overcast (otherwise leading to diurnal 

warming). This applies only to surface ship mid-frequency active mainframe 

sonar. 

Assessment: This mitigation measure could not be effectively implemented or 

uniformly employed in RIMPAC. Additionally, there is no evidence to indicate it is 

effective or that it provides protection for marine mammals in addition to that 

provided in measure (f). 


This mitigation measure could not be accurately and uniformly employed during 

RIMPAC. The exercise headquarters found so many variations in water conditions 


16

Appendix C 

across the exercise area that the determination of “strong surfacing ducting” was futile. It 

was problematic for the following reasons: 

(1) There is so much local variation in the Pacific Fleet training areas that it would be 

necessary for a ship to constantly monitor the local environment to accurately comply 

with this measure. Measurements taken during RIMPAC indicated large variation in the 

presence or absence of significant surface ducts over relatively short distances in the 

Hawaiian operating areas. 

(2) The models used in forecasting a significant surface duct used high resolution that 

still resulted in a generalized sea state, SVP, and cloud cover over a large operational area 

covered by exercise participants. Measured local variations were so different from these 

forecasts that the determination that "significant surface duct condition do/do not exist" 

was inherently inaccurate. 

(3) There is no means to know if the local SVP ahead of the ship is the same as the SVP 

being measured. Oceanographic models are years away from being able to model the 

ocean's structure in four dimensions at the resolution required to accurately predict SVP 

changes on a detailed scale. 

(4) There is no allowance for local variations from tidal flux, differential sea states (as 

frequently seen in channels or shear lines to the southwest of most points of land in 

Hawaii), and currents/eddies - all of which have a significant effect on surface ducting. 


Because the process to determine if a significant surface duct exists across the entire 

exercise area could not be effectively implemented or uniformly employed, recommend 

this measure not be included in future authorizations. 

In addition, this measure seems to have been an outgrowth of the apparent evidence that 

significant surface ducting may have played a role in previous incidents involving 

stranding of beaked whales in certain conditions. There is no evidence to suggest that 

significant surface ducting in and of itself causes MFA sonar’s overall effects to be 

increased, and it is still not known whether the presence of surface ducting was actually 

significant in the known beaked whale stranding incidents. 

Measure (h) 


(h) In low visibility conditions (i.e., whenever the entire safety zone cannot 

be effectively monitored due to nighttime, high sea state, or other factors), the 

Navy will use additional detection measures, such as infrared (IR) or enhanced 

passive acoustic detection. If detection of marine mammals is not possible out to 

the prescribed safety zone, the Navy will power down sonar (per the safety zone 

criteria above) as if marine mammals are present immediately beyond the extent 

of detection. (For example, if detection of marine mammals is only possible out to 

700 m, the Navy must implement a 6 dB power-down, as though an animal is 

present at 701 m, which is inside the 1000 m safety zone) 


17

Appendix C 

Assessment: This mitigation measure was not necessary in RIMPAC since a 

condition of low visibility, as defined by the measure, was never encountered. In 

other words, at night lookouts were still able to monitor out to the limits of the 

safety zone. This mitigation measure has the potential to directly affect training and 

therefore the effectiveness of the military readiness activity. 


This measure would preclude use of a sensor when tactically required and significantly 

affects the military readiness activity. Navy must be allowed to operate MFAS at night 

and in heavy seas using the full potential of sonar as a sensor. 

There is no “enhanced passive acoustic detection” – Navy ships continuously use every 

passive device available, and the state of technology for detecting marine mammals 

passively is rudimentary at best. 


This procedure has the potential to directly affect the military readiness activity. 

Recommend it not be incorporated in future authorizations or modified as to avoid 

impacting training realism in low visibility conditions. 

Measure (i) 


(i) Helicopters shall observe/survey the vicinity of an ASW exercise for 10 

minutes before deploying active (dipping) sonar in the water. Helicopters shall 

not dip their sonar within 200 yards of a marine mammal and shall cease pinging 

if a marine mammal closes within 200 yards after pinging has begun. 



None. 


Continue as standard Navy protective measures. 

Measure (j) 


(j) The Navy will operate sonar at the lowest practicable level, not to 

exceed 235 dB, except for occasional short periods of time to meet tactical 

training objectives. 



None. 


18

Appendix C 


Continue as standard Navy protective measures. 

Measure (k) 


(k) With the exception of three specific choke-point exercises (special 

measures outlined in item (m)), the Navy will not conduct sonar activities in 

constricted channels or canyon-like areas. 

Assessment: This mitigation measure could not be precisely implemented, 

significantly impacts military readiness, has no scientific basis for implementation in 

the Hawaiian Islands, and provided no observable protection to marine mammals 

during this exercise. 


Restricting Navy operations in choke-points are contrary to ASW training requirements. 

This measure limits the ability to train realistically in the known diesel submarine threat 

environment and directly impacts a vital military readiness activity. 

This prohibition against MFAS use in “constricted channels or canyon-like areas” could 

not be precisely implemented or uniformly enforced because there were no defining 

metrics. The terms “constricted channels or canyon-like areas” have no meaning within 

the Navy or in maritime communities and were not defined by the IHA. Additionally, 

there is no scientific basis for a determination that such vaguely defined bathymetric 

features tend to concentrate marine mammals and/or have a greater potential to effect 

marine mammals, and therefore warrant prohibitive measures. 

RIMPAC 2006 completed three monitored choke-point events with observations before, 

during, and after the events. There was no indication of any marine mammal impacts 

from the Navy monitors or from the non-governmental civilian monitors who were out in 

small vessels off Kauai and Hawaii Island during these events. 

There is no data for the Pacific indicating the need for the precautionary prohibition 

against choke-point exercises, “constricted channels”, or “canyon-like areas”. There 

have been 19 previous RIMPAC exercises and numerous JTFEX, USWEX and 

COMTUEX exercises in SOCAL and Hawaii involving choke-point exercises that have 

occurred over many years without an indication of effect on any marine mammals. 


This procedure had no observable effect on the protection of mammals during this 

exercise. Recommend future authorizations contain better definition of bathymetric 

features of concern and that the features of concern are based on definitive evidence of 

increased risk to marine mammals. 


19

Appendix C 

Measure (l) 


(l) With the exception of three specific “choke-point” exercises (special 

measures outlined in item (m)), the Navy will not operate mid-frequency sonar 

within 25 km of the 200 m isobath. 

Assessment: This is no scientific basis indicating this measure is warranted in the 

Pacific and no basis for the specific metrics (25 km of the 200 m isobath). In 

addition, there are no standard US nautical charts depicting depths in meters 

making this a difficult measure to implement in the field. This measure significantly 

impacts military readiness. 


During RIMPAC this measure precluded active ASW training in the littoral region, 

which significantly impacted realism and training effectiveness. Prohibitions against 

operating in littoral areas are contrary to ASW training requirements. This measure 

affects the ability to train realistically in the known diesel submarine threat environment 

and directly impacts vital military readiness activity. (Note: Any reference to isobath 

curves should be in fathoms vice meters. There are no approved NOAA nautical charts 

that provide for a 200m isobath.) 


This procedure had no observable effect on the protection of mammals during this 

exercise and therefore its value is uncertain. Its effect on realistic training is, however, 

clear and significant. The areas prohibited by this measure are the very ones where 

training against quiet submarines is most important. With respect to the presence of 

marine mammals, there is no scientific basis for the metrics particular to the 200 m 

isobath nor the 25 km distance from the 200 m isobath. In addition, the lengthy history 

of sonar use in the Hawaiian Islands and SOCAL without any strandings or apparent 

effect on marine mammals argues that this measure is unnecessary. Recommend it not be 

included in future authorizations. 

Measure (m) 

This measure deals with “choke-point” events, contains various subparts, and reads: 

(m) The Navy will conduct no more than three “choke-point” exercises. 

These exercises will occur in the Kaulakahi Channel (between Kauai and Niihau) 

and the Alenuihaha Channel (between Maui and Hawaii). These exercises fall 

outside of the requirements listed above in (k) and (l), i.e., to avoid canyon-like 

areas and to operate sonar farther than 25 km from the 200 m isobath. The 

additional measures required for these three choke-point exercises are as follows: 

Assessment: This measure is not a mitigation and therefore requires no assessment. 

Measure (m) Part (i) 

This part of measure (m) reads: 


20

Appendix C 

(i) The Navy will provide NMFS (Stranding Coordinator and Protected 

Resources, Headquarters) and the Hawaii marine patrol with information 

regarding the time and place for the choke-point exercises 24 hours in advance of 

the exercises. 

Assessment: This measure is a monitoring effort vice a mitigation and does not 

provide additional protection to marine mammals. 


Notification to NMFS did not meet the “24 hours in advance” requirement for several 

reasons. Since choke-point events are scheduled to occur within a range of time, such as 

within a 24 hour period, the exercise participants could not provide specific times for 

when the choke-point transit would begin. The actual transit of the channel occurred 

based on the on-scene Commander's read of the tactical situation as it developed over the 

course of many hours. To address this issue during RIMPAC 2006, and in coordination 

with NMFS Pacific Islands Regional Office, NMFS was kept apprised of the timeframe 

as it became available. 


The coordination with stranding offices and Navy’s cooperation with NMFS in the event 

of a stranding are established procedures and should not be confused with mitigation 

measures mandated for a specific exercise. In addition, the emphasis on monitoring for 

strandings during naval exercises has the potential to perpetuate unsubstantiated 

correlations of strandings as being caused by MFAS use. If a comprehensive marine 

mammal monitoring program is warranted, it should be pursued by NMFS through 

implementation of statistically based monitoring protocols and a research and sampling 

design that objectively assesses stranding occurrence across all potential causal factors, 

resulting in a baseline understanding of strandings for a given region. 

Note: There is no “Hawaii marine patrol” and as a result, this component of the 

mitigation requirement could not be implemented. 

Measure (m) Part (ii) 


(ii) The Navy will have at least one dedicated Navy marine mammal 

observer who has received the NMFS-approved training mentioned above in (a), on 

board each ship and conducting observations during the operation of mid-frequency 

tactical sonar during the choke-point exercises. The Navy has also authorized the 

presence of two experienced marine mammal observers (non-Navy personnel) to embark 

on Navy ships for observation during the exercise. 

Assessment: The first component of this measure duplicates standard Navy training 

requirements and is unnecessary. The “experienced marine mammal observers 

(non-Navy personnel)” detected no marine mammals during the time they were 

embarked and therefore provided no additional capability or protection to marine 

mammals during this exercise. 


21

Appendix C 


None for this exercise, however, it is usually not feasible to provide transportation, 

berthing, and manning for non-navy personnel aboard exercise vessels. In some cases, 

inclusion of these observers would result in the inability to accommodate essential Navy 

personnel associated with the exercise such as trainers and data collection personnel. 

The requirement for a “dedicated Navy marine mammal observer” indicates a 

fundamental misunderstanding of Navy practices. This measure duplicates the watch 

standing requirements inherent in measures (a) and (b), because all lookouts have been 

trained to be “dedicated Navy marine mammal observers”. Any marine mammals 

detected are reported to the OOD as required under normal procedures, regardless of 

whether the ship is conducting a choke point transit. 

NMFS embarked two observers on 19 July to the CVN during one of the Kaulakahi 

choke-point events, because this served as a superb viewing platform in the approximate 

center of ASW operations. These observers detected no marine mammals, and therefore 

provided no additional value as a mitigation measure during this exercise. As discussed 

under measures (a) and (b), Navy spotters receive sufficient training to undertake the 

required tasks. Use of Navy lookouts is the most effective means to ensure quick and 

effective communication within the command structure and facilitate implementation of 

protective measures if marine species are spotted. 


Navy lookouts have the skills and training to detect marine mammals without 

augmentation by additional non-navy observers onboard ships. Additional non-navy 

observers have the potential to adversely impact an exercise, and did not appear to 

improve marine mammal detection cabability during RIMPAC. Recommend this 

measure not be included in future authorizations. 

Measure (m) Part (iii) 


(iii) Prior to start up or restart of sonar, the Navy will ensure that a 2000 

m radius around the sound source is clear of marine mammals. 

Assessment: This is unnecessary given that the safety zones established in Measure 

(f) already provide adequate protection. 


None. 

Conclusion 

This measure is inconsistent with the provisions required in Measure ((f); Safety Zones). 

Recommend it not be included in future authorizations. 


22

Appendix C 

Measure (m) Part (iv) 


(iv) The Navy will coordinate a focused monitoring effort around the 

choke-point exercises, to include pre-exercise monitoring (2 hours), duringexercise 

monitoring, and post-exercise monitoring (1-2 days). This monitoring 

effort will include at least one dedicated aircraft or one dedicated vessel for realtime 

monitoring from the pre- through post-monitoring time period, except at 

night. The vessel or airplane may be operated by either dedicated Navy 

personnel, or non-Navy scientists contracted by the Navy, who will be in regular 

communication with a Tactical Officer with the authority to shut-down, powerdown, 

or delay the start-up of sonar operations. These monitors will 

communicate with this Officer to ensure the 2000 m safety zone is clear prior to 

sonar start-up, to recommend power-down and shut-down during the exercise, 

and to extensively search for potentially injured or stranding animals in the area 

and down-current of the area post-exercise. 

Assessment: This measure is relatively costly and did not result in any marine 

mammal sightings requiring MFAS source reduction or shutdown. 


The time and money spent to provide this mitigation measure appeared to provide no 

additional protection to marine mammals. 

Observations 

The monitoring efforts consisted of shore-based observers, aerial surveys and the routine 

patrols of Torpedo Recovery Boats. Though these surveys spotted numerous marine 

mammals, none of the mammal detected were in the vicinity of exercise participants or 

provided protection from exercise MFAS. For marine mammals detected before the 

event, there was no way to determine if they were likely to move into or out of an 

exercise that was miles from a given observation/detection location. 

The capability of sighting marine mammals from both surface and aerial platforms 

participating in the exercise provides excellent survey capabilities using the Navy’s 

existing exercise assets. Six of the 29 marine mammal detections were made by Navy 

aerial assets participating in the RIMPAC exercise. 

Given the vast distances involved, it was impossible to ensure a 2000 m safety zone was 

clear of every single participant by these additional monitors. The monitors could not 

recommend power-down or shut-down during the exercise because the focus of their 

efforts was so dispersed. 

Although monitors did serve to extensively search for potentially injured or stranded 

animals in the area they were assigned to observe, none were detected and the value 

provided by this time consuming and expensive search is questionable. 


23

Appendix C 

Other comments on this measure: The provision for searching “down-current of the area 

post-exercise” fails to recognize that an exercise area may involve many hundreds of 

square miles of ocean with variable currents. 

Shore-based monitors’ observations: Resident groups of spinner dolphins nearshore at 

Kekaha, Kauai on five consecutive mornings before, during, and after two choke point 

exercises taking place in the Kaulakahi Channel. Three days of shore-based observation 

from the Kohala Coast of Hawaii Island occurred around a choke-point exercise taking 

place in the Alenuihaha Channel. A pod of bottlenose dolphins was observed feeding 

nearshore a few hours apart on the first day of observation. Over the eight days of shorebased 

observation, there were no unusual behaviors exhibited by these animals. 

Aerial survey observations: Aerial surveys covered these same channels over six days 

(18 hours). This aerial survey effort was generally hampered by rough sea state 

conditions. Two days of aerial survey had to be cancelled due to safety requirements 

concerning the use of unmanned drones and weapon firing on the range at PMRF on 

those days. There were a total of 13 sightings of marine mammals over the six days with 

no unusual behavior or activity observed. 

Finally, of note, the aerial surveys conducted around the time of the choke point exercises 

showed that “the densities of marine mammal species reported here is identical with that 

normally seen for the Hawaiian Islands, albeit at different times of the year.” Therefore, 

although some 30-40 ships conducted a wide ranging exercise over more than three 

weeks and employed MFA sonar extensively, marine mammal densities remained stable, 

and observers detected no unusual behavior in the marine mammals they saw. 


This procedure is a monitoring measure vice a mitigation measure and had no 

demonstrable impact on the protection of mammals during RIMPAC. Due to the 

experience of Navy aircrews and their sensitivity to detecting marine mammals, as well 

as the cost involved in contracting these services, recommend that for future 

authorizations, only Navy assets be considered for increased monitoring, and then only 

when required in the aggregations of conditions which show the most potential for risk to 

marine mammals. 

Measure (m) Part (v) 


(v) The Navy will further contract an experienced cetacean researcher to 

conduct systematic aerial reconnaissance surveys and observations before, 

during, and after the choke-point exercises with the intent of closely examining 

local populations of marine mammals during the RIMPAC exercise. 

Assessment: This measure duplicates measure (m)(iv) and provides no additional 

protection for marine mammals. 


24

Appendix C 


None. However, the money spent to provide this mitigation measure provided no 

observable protection to marine mammals during this exercise and cannot be resourced 

for routine Navy’s exercises. 


The contracted “experienced cetacean researcher” did not spot any marine mammals in 

the vicinity of the exercise. Recommend this measure not be included in future 

authorizations. 

Measure (m) Part (vi) and (vii) 

These parts of measure (m) reads: 

(vi) Along the Kaulakahi Channel (between Kauai and Niihau), shoreline 

reconnaissance and nearshore observations will be undertaken by a team of 

observers located at Kekaha (the approximate mid point of the Channel). 

Additional observations will be made on a daily basis by range vessels while 

enroute from Port Allen to the range at PMRF (a distance of approximately 16 

nmi) and upon their return at the end of each day's activities. Finally, 

surveillance of the beach shoreline and nearshore waters bounding PMRF will 

occur randomly around the clock a minimum four times in each 24 hour period. 

(vii) In the Alenuihaha Channel (between Maui and Hawaii), the Navy will 

conduct shoreline reconnaissance and nearshore observations by a team of 

observers rotating between Mahukona and Lapakahi before, during, and after the 

exercise. 

Assessment: This measure does not appear to provide additional protection for 

marine mammals and is unnecessary. 


None. However, the personnel resources spent to provide this mitigation measure 

provided no demonstrable protection to marine mammals during this exercise and cannot 

be routinely resourced for Navy’s exercises. 


This procedure did not result in any effective mitigation during RIMPAC. Tasking 

personnel to observe a portion of the shoreline during a choke-point as a monitoring 

measure has no scientific basis (no research questions, research design, or sampling 

approach). 

Although the shore based observers saw marine mammals and sea turtles, and these 

observations were reported to the RIMPAC Battle Watch as required, the observed 

marine species were miles from any exercise events and hours before the choke-point 

transits began. These observations were of no utility as a mitigation measure. 

Recommend this measure not be included in future authorizations. 


25

Appendix C 

Measure (n) 


(n) The Navy will continue to coordinate with NMFS on the 

"Communications and Response Protocol for Stranded Marine Mammal Events 

During Navy Operations in the Pacific Islands Region" that is currently under 

preparation by NMFS PIRO to facilitate communication during RIMPAC. The 

Navy will coordinate with the NMFS Stranding Coordinator for any unusual 

marine mammal behavior, including stranding, beached live or dead cetacean(s), 

floating marine mammals, or out-of-habitat/milling live cetaceans that may occur 

at any time during or shortly after RIMPAC activities. After RIMPAC, NMFS and 

the Navy (CPF) will prepare a coordinated report on the practicality and 

effectiveness of the protocol that will be provided to Navy/NMFS leadership. 

Assessment: This measure documents what is standard procedure. 


None. 


This requirement documents Navy’s standard procedure. 

SECTION 2 SUMMARY 

During RIMPAC 06, there were 472 total hours of mid-frequency active sonar (MFAS) 

use. There were no reported observations of behavioral disturbance of marine mammals 

during the exercise. The Navy’s previously developed and used mitigation measures 

from PMAP, as modified for RIMPAC 06, appeared to be effective in protecting marine 

mammals observed near exercise ships. Mitigation measures agreed to for issuance of 

the IHA that went beyond standard Navy measures had no observable effect on 

protection of marine mammals in this exercise, and their application unnecessarily 

increased the cost of the exercise or had a negative effect on the fidelity of training. 

As the first major exercise for which Navy applied for an authorization under MMPA, 

RIMPAC ’06 presented unique challenges from the perspective of regulatory 

requirements and public perception. We anticipate that future authorizations for 

exercises and operating area coverage will recognize the differences in those areas as 

well as how developing science will inform our understanding of the role of mitigation 

measures. 


26

Appendix C 

SECTION 3: Monitoring Results 

The IHA requires this report contain, “Results of the marine species monitoring (realtime 

monitoring from all platforms, independent aerial monitoring, shore-based 

monitoring at chokepoints, etc.) before, during, and after the RIMPAC exercises”. This 

section of the report, therefore, provides a summary of the detections of marine species 

from all exercise participants, the aerial reconnaissance survey, and shore-based 

monitoring efforts associated with the RIMPAC 06 exercise. 

Figure 2. Location of marine mammals sighted by exercise participants depicted in red. 

Locations with multiple sightings are depicted by a single box. The line of longitude 

shown is 160ْ West and the latitude is 20ْ North. 

Figure 2 depicts the approximate location of marine mammals that were sighted by 

exercise participants. This is a skewed sample since there were no attempts made to 

detect marine mammals by other means in areas not being used by exercise participants. 

In addition to these sightings, marine species detections occurred as a result of two other 


27

Appendix C 

IHA mandated measures consisting of an aerial reconnaissance effort and shore-based 

monitors. 

As noted previously, the additional monitoring requirements consisting of aerial and 

shipboard monitoring, and shore-based observations before, during, and after choke-point 

events. These monitoring efforts were required by NMFS as a sampling strategy to 

determine if there was any observable effect on marine mammals during ASW training 

events taking place in the channels between two sets of islands. These measures arose 

from a precautionary concern that MFAS use in the channels could possibly have greater 

potential to impact marine mammals, despite the lack of evidence suggestive of any 

problems in this regard from any of the previous 19 RIMPAC exercises. The cost to 

implement these monitoring requirements was approximately $66,000 for RIMPAC 06 

A separate report providing details from the shore-based monitors’ observations is 

presented in Appendix B and summarized here. These shore-based observations took 

place centered on two channels between the islands. The first of these monitoring efforts 

took place at Kekaha on Kauai. This is the approximate mid point along the Kaulakahi 

Channel between Kauai and Niihau, and spanned five consecutive days before, during, 

and after two choke point exercises taking place in that channel. Each morning of the 

five days, a pod of spinner dolphins were present 300-400 meters offshore. There were 

no unusual or abnormal behaviors observed. Sea turtles were also observed on two days. 

Additional observations made on a daily basis by range vessels while enroute from Port 

Allen through the channel to the range at PMRF and surveillance of the beach shoreline 

and nearshore waters bounding PMRF did not result in any marine mammal detections. 

Shore-based observation also took place on the Kohala Coast of Hawaii Island for three 

full days occurred around a choke-point exercise taking place in the Alenuihaha Channel 

between Hawaii Island and Maui. A pod of bottlenose dolphins was observed feeding 

during the first day of observation. There were no unusual or abnormal behaviors 

observed. Sea turtles were also observed on two days. 

Aerial surveys covered these same channels over six days (approximately 18 hours flight 

time) as detailed in Appendix C. This aerial survey effort was generally hampered by 

rough sea state conditions. Two days of aerial survey had to be cancelled due to safety 

requirements concerning the use of unmanned drones and weapon firing on the range at 

PMRF on those days. There were a total of 13 sightings of marine mammals over the six 

days with no unusual behavior or activity observed. 

Navy also authorized the presence of two experienced marine mammal observers (non- 

Navy personnel) to embark on a Navy ship for observation during a choke-point exercise. 

NMFS did not have any marine mammal observers available and alternatively embarked 

two Fisheries Program observers on 19 July to an available CVN during one of the 

Kaulakahi choke-point events. This ship was chosen since it served as a superb viewing 

platform with a large height of eye and unobstructed visibility in the approximate center 

of ASW operations. These observers detected no marine mammals. 


28

Appendix C 

In summary, there were 13 sightings of marine mammals from the air over approximately 

18 hours of flight time. Shore based observation for 80 hours of effort by two people 

produced five sightings of a resident pod of spinner dolphins over five consecutive days 

on Kauai and a pod of bottlenose dolphins offshore of Hawaii Island. The results of these 

monitoring efforts provided no evidence of indicating there were any effects on the 

detected marine mammals as a result of the ASW exercises, which took place in the 

adjacent channels. 


29

Appendix C 

SECTION 4: Sonar Usage and Marine Mammals 

The IHA requires that this report contain, "As much information (unclassified and, to 

appropriately cleared recipients, classified “secret”) as the Navy can provide including, 

but not limited to, where and when sonar was used (including sources not considered in 

take estimates, such as submarine and aircraft sonars) in relation to any measures 

received levels (such as sonobuoys or on PMRF range), source levels, numbers of 

sources, and frequencies so it can be coordinated with observed cetacean behaviors." 

Section 4 of the report provides information on the location and hours of active MFAS 

used during RIMPAC 06. The IHA also required as much data as could be provided on 

measured received levels, source levels, numbers of sources and frequencies so it could 

be coordinated with observed cetacean behaviors. Typically, there are no measurements 

(calibrated or otherwise) of actual sound levels made during an exercise and none were 

made during RIMPAC 06. Source levels, numbers of sources, and frequencies are 

classified since that information would provide potential adversaries with important 

tactical data. The observance of marine mammals by Navy assets only occurred as very 

brief encounters given the mitigation measures are designed to limit interaction to a 

minimum. 

Observations of marine species and their behaviors resulting from the aerial 

reconnaissance and shore-based monitoring (as previously detailed in Section 3) observed 

no unusual behaviors for coordination with MFAS use. There were no indications from 

the observations that the presence of exercise participants had any affect on any marine 

mammals. 

The requirement to report where and when sonar was used so it can be coordinated with 

observed cetacean behaviors can not be completed since no animals were observed doing 

anything unusual or behaving in any overt manner. Information presented previously in 

Table 1 provides a list of instances when marine mammals were detected and sonar was 

being used. 

As noted previously, during RIMPAC 06, there were 199 anti-submarine warfare (ASW) 

events and 472 total hours of hull mounted MFAS. This was less than the anticipated 

number of hours (532) presented in the RIMPAC 2006 Supplemental Environmental 

Assessment as a result of a temporary restraining order (TRO) restricting the use of 

MFAS arising from a lawsuit (NRDC v. Winter) in effect for the first days of the 

exercise. During the period of this TRO, three days of scheduled MFAS training (25 

events) were lost including 4 live fire events, 14 P-3 ASW events, and 7 surface ASW 

events. 

In addition to the 472 hours of hull mounted MFAS use, there were approximately 115 

hours of operations involving both passive DIFAR and active DICASS sonobuoys 

reported for RIMPAC 06. This quantity of operational hours does not equate to 115 


30

Appendix C 

hours of active sonar use since only approximately 10% of the sonobuoys expended 4 

were active DICASS and they are commanded to transmit an active ping only as required 

by the tactical situation. In short, an individual DICASS sonobuoy, even though 

deployed, may never be activated during an event. In other instances, DICASS buoys are 

not deployed until a possible contact is identified and the need to localize the target 

arises. There is no standard data collection reporting that would serve as a means to 

determine how much actual active sonar time resulted from DICASS sonobuoy use 

during RIMPAC. 

Finally, there were approximately 45 hours of operations involving the use of dipping 

sonars deployed from helicopters. Similar to the case for sonobuoys, there is no standard 

data collection reporting that would serve as a means to determine how much actual 

active sonar time resulted from this number of hours of dipping sonar operation. During 

RIMPAC, dipping sonars were not in a search capacity but instead used for localization 

or confirmation of suspected contacts. In can be estimated that in this capacity dipping 

sonars, which are used very briefly (2-5 pulses a few hundred msec in duration) 

approximately every 10 minutes, would have resulted in approximately 11-12 minutes of 

active sonar over a 20 day period spread across the RIMPAC exercise area. 

4 There were 2,713 passive and 292 active sonobuoys expended in RMPAC 06. 


31

Appendix C 



Appendix C 

Appendix (A) 

PROPOSED MITIGATION MEASURES FOR MFAS 

DURING MAJOR ASW EXERCISES 

I. General Maritime Protective Measures: Personnel Training: 

1. All lookouts onboard platforms involved in ASW training events will review the 

NMFS approved Marine Species Awareness Training (MSAT) material prior to 

MFAS use. 

2. All Commanding Officers, Executive Officers, and officers standing watch on the 

Bridge will have reviewed the MSAT material prior to a training event employing 

the use of MFAS. 

3. Navy lookouts will undertake extensive training in order to qualify as a 

watchstander in accordance with the Lookout Training Handbook (NAVEDTRA 

12968-B). 

4. Lookout training will include on-the-job instruction under the supervision of a 

qualified, experienced watchstander. Following successful completion of this 

supervised training period, Lookouts will complete the Personal Qualification 

Standard program, certifying that they have demonstrated the necessary skills 

(such as detection and reporting of partially submerged objects). This does not 

forbid personnel being trained as lookouts counted as those listed in previous 

measures so long as supervisors monitor their progress and performance. 

5. Lookouts will be trained in the most effective means to ensure quick and effective 

communication within the command structure in order to facilitate 

implementation of protective measures if marine species are spotted. 

II. General Maritime Protective Measures: Lookout and Watchstander Responsibilities: 

6. On the bridge of surface ships, there will always be at least three people on watch 

whose duties include observing the water surface around the vessel. 

7. All surface ships participating in ASW exercises will, in addition to the three 

personnel on watch noted previously, have at all times during the exercise at least 

two additional personnel on watch as lookouts. 

8. Personnel on lookout and officers on watch on the bridge will have at least one set 

of binoculars available for each person to aid in the detection of marine mammals. 

9. On surface vessels equipped with MFAS, pedestal mounted “Big Eye” (20x110) 

binoculars will be present and in good working order to assist in the detection of 


A-1

Appendix C 

marine mammals in the vicinity of the vessel. 

10. Personnel on lookout will employ visual search procedures employing a scanning 

methodology in accordance with the Lookout Training Handbook (NAVEDTRA 

12968-B). 

11. After sunset and prior to sunrise, lookouts will employ Night Lookouts 

Techniques in accordance with the Lookout Training Handbook. 

12. Personnel on lookout will be responsible for reporting all objects or anomalies 

sighted in the water (regardless of the distance from the vessel) to the Officer of 

the Deck, since any object or disturbance (e.g., trash, periscope, surface 

disturbance, discoloration) in the water may be indicative of a threat to the vessel 

and its crew or indicative of a marine species that may need to be avoided as 

warranted. 

III. Operating Procedures 

13. A Letter of Instruction, Mitigation Measures Message or Environmental Annex to 

the Operational Order will be issued prior to the exercise to further disseminate 

the personnel training requirement and general marine mammal protective 

measures. 

14. Commanding Officers will make use of marine species detection cues and 

information to limit interaction with marine species to the maximum extent 

possible consistent with safety of the ship. 

15. All personnel engaged in passive acoustic sonar operation (including aircraft, 

surface ships, or submarines) will monitor for marine mammal vocalizations and 

report the detection of any marine mammal to the appropriate watch station for 

dissemination and appropriate action. 

16. During MFAS operations, personnel will utilize all available sensor and optical 

systems (such as Night Vision Goggles to aid in the detection of marine 

mammals. 

17. Navy aircraft participating in exercises at sea will conduct and maintain, when 

operationally feasible and safe, surveillance for marine species of concern as long 

as it does not violate safety constraints or interfere with the accomplishment of 

primary operational duties. 

18. Aircraft with deployed sonobuoys will use only the passive capability of 

sonobuoys when marine mammals are detected within 200 yards of the sonobuoy. 

19. Marine mammal detections will be immediately reported to assigned Aircraft 

Control Unit for further dissemination to ships in the vicinity of the marine 

species as appropriate where it is reasonable to conclude that the course of the 


A-2

Appendix C 

ship will likely result in a closing of the distance to the detected marine mammal. 

20. Safety Zones - When marine mammals are detected by any means (aircraft, 

shipboard lookout, or acoustically) within 1,000 yards of the sonar dome (the 

bow), the ship or submarine will limit active transmission levels to at least 6 dB 

below normal operating levels. 

(i) Ships and submarines will continue to limit maximum transmission levels by 

this 6-dB factor until the animal has been seen to leave the area, has not been 

detected for 30 minutes, or the vessel has transited more than 1,000 yards beyond 

the location of the last detection. 

(ii) Should a marine mammal be detected within or closing to inside 500 yards of 

the sonar dome, active sonar transmissions will be limited to at least 10 dB below 

the equipment's normal operating level. Ships and submarines will continue to 

limit maximum ping levels by this 10-dB factor until the animal has been seen to 

leave the area, has not been detected for 30 minutes, or the vessel has transited 

more than 1,000 yards beyond the location of the last detection. 

(iii) Should the marine mammal be detected within or closing to inside 200 yards 

of the sonar dome, active sonar transmissions will cease. Sonar will not resume 

until the animal has been seen to leave the area, has not been detected for 30 

minutes, or the vessel has transited more than 1,000 yards beyond the location of 

the last detection. 

(iv) Special conditions applicable for dolphins and porpoises only: If, after 

conducting an initial maneuver to avoid close quarters with dolphins or porpoises, 

the Officer of the Deck concludes that dolphins or porpoises are deliberately 

closing to ride the vessel's bow wave, no further mitigation actions are necessary 

while the dolphins or porpoises continue to exhibit bow wave riding behavior. 

(v) If the need for power-down should arise as detailed in “Safety Zones” above, 

Navy shall follow the requirements as though they were operating at 235 dB - the 

normal operating level (i.e., the first power-down will be to 229 dB, regardless of 

at what level above 235 sonar was being operated). 

21. Prior to start up or restart of active sonar, operators will check that the Safety 

Zone radius around the sound source is clear of marine mammals. 

22. Sonar levels (generally) - Navy will operate sonar at the lowest practicable level, 

not to exceed 235 dB, except as required to meet tactical training objectives. 

23. Helicopters shall observe/survey the vicinity of an ASW exercise for 10 minutes 

before the first deployment of active (dipping) sonar in the water. 

24. Helicopters shall not dip their sonar within 200 yards of a marine mammal and 

shall cease pinging if a marine mammal closes within 200 yards after pinging has 


A-3

Appendix C 

begun. 

25. Submarine sonar operators will review detection indicators of close-aboard 

marine mammals prior to the commencement of ASW operations involving active 

mid-frequency sonar. 

26. Increased vigilance during major ASW training exercises with tactical active 

sonar when critical conditions are present. 

Navy should avoid planning major ASW training exercises with MFAS in areas 

where they will encounter conditions which, in their aggregate, may contribute to 

a marine mammal stranding event. Of particular concern are beaked whales, for 

which strandings have been associated, in theory, with MFAS operations. 

The conditions to be considered during exercise planning include: 

(1) Areas of at least 1000 m depth near a shoreline where there is a rapid 

change in bathymetry on the order of 1000-6000 meters occurring across a 

relatively short horizontal distance (e.g., 5 nm). 

(2) Cases for which multiple ships or submarines (≥ 3) operating MFAS 

in the same area over extended periods of time (≥ 6 hours) in close proximity (≤ 

10NM apart). 

(3) An area surrounded by land masses, separated by less than 35 nm and 

at least 10 nm in length, or an embayment, wherein operations involving multiple 

ships/subs (≥ 3) employing MFAS near land may produce sound directed toward 

the channel or embayment that may cut off the lines of egress for marine 

mammals. 

(4) Though not as dominant a condition as bathymetric features, the 

historical presence of a strong surface duct (i.e. a mixed layer of constant water 

temperature extending from the sea surface to 100 or more feet). 

If the major exercise must occur in an area where the above conditions exist in 

their aggregate, these conditions must be fully analyzed in environmental 

planning documentation. Navy will increase vigilance by undertaking the 

following additional protective measure: 

A dedicated aircraft (Navy asset or contracted aircraft) will undertake 

reconnaissance of the embayment or channel ahead of the exercise participants to 

detect marine mammals that may be in the area exposed to active sonar. All 

safety zone power down requirements described above apply. 

IV. Coordination and Reporting 

27. Navy will coordinate with the local NMFS Stranding Coordinator for any unusual 

marine mammal behavior and any stranding, beached live/dead or floating marine 

mammals that may occur at any time during or within 24 hours after completion 

of mid-frequency active sonar use associated with ASW training activities. 


A-4

Appendix C 

28. Navy will submit a report to the Office of Protected Resources, NMFS, within 

120 days of the completion of a Major Exercise. This report must contain a 

discussion of the nature of the effects, if observed, based on both modeled results 

of real-time events and sightings of marine mammals. 

29. If a stranding occurs during an ASW exercise, NMFS and Navy will coordinate to 

determine if MFAS should be temporarily discontinued while the facts 

surrounding the stranding are collected. 


A-5

Appendix C 



Appendix C 

Appendix (B) 

RIMPAC 2006 

NEARSHORE MONITORING 

FIELD REPORT 

JULY 2006 

Prepared by: 

Naval Facilities Engineering Command, Pacific 

Environmental Planning Division 

258 Makalapa Drive, Ste. 100 

Pearl Harbor, HI 96860 


B-1

Appendix C 



Appendix C 

INTRODUCTION 

In support of RIMPAC 2006, nearshore monitoring for marine mammals and sea turtles 

was conducted during July 16-20 from Kekaha Beach, Kauai, Hawaii and July 24-26 

from Mahukona and Kapaà Beach Park, Kohala Coast, Hawaii. The locations were 

chosen based upon their proximity to the Kalaukahi (between Kauai and Niìhau) and 

Alanuihaha (between Hawaii and Maui) Channels. The purpose of the monitoring was 

to 1) provide the Navy ships with information on species in the nearshore waters, 2) 

provide observations of marine mammal behavior before, during and after swept-channel 

(choke point) exercises, and 3) to monitor the beach and nearshore waters for marine 

species exhibiting abnormal behavior (offshore animals nearshore, congregations of 

offshore animals, strandings, etc). 

METHODS 

Shore-based monitoring was conducted from 0700 to 1830 hours with two observers 

using hand-held 10x42 binoculars and un-aided eye. Monitoring schedule corresponds to 

one day before and after each planned swept-channel exercise, two in the Kalaukahi 

channel and one in the Alanuihaha Channel. All observations were conducted by one 

experienced Navy marine mammal observer and one field assistant. 

Kekaha Beach observations were conducted essentially at sea level. The sandy beach 

allowed for observers to walk the length of the beach north to the PMRF, Barking Sands 

Boundary and south to the end of Kehaka Beach (3 miles). Walks were conducted 

between two and four times per day. One observer would remain on station (near the 

lifeguard tower) as the other walked up the beach. The horizon from sea level is a 

distance of approximately 5 km. 

Observations were conducted from Mahukona on July 23 rd from 0700 to 1200 hours, but 

Kapaà Beach Park was chosen for the rest of the 2.5 days since it offered a better view 

of the Alanuihaha Channel. Kapaà Beach Park is a boulder beach, and observations 

were conducted at approximately 7m above sea level (horizon distance approximately 5 

miles). A point to the north of the beach park resulted in a consistently lower sea state 

close to shore than in the open channel. On two days, portions of the coastline to the 

north of Kapaà Beach Park (between Upolu Point and Moòkini Heiau) was driven using 

a 4x4 vehicle to check the boulder beaches for stranded or distressed animals. 

Data were collected on visibility, Beaufort sea state, marine mammals observed, sea 

turtles observed, and Navy ships/operations observed. While at Kehaka, data were also 

collected on commercial tour boats that were observed interacting with resident spinner 

dolphins. 


B-2

Appendix C 

RESULTS 

Table 1 provides daily observation information. Only two species of marine mammals 

were observed, spinner dolphins (Stenella longitrostris) and bottlenose dolphins 

(Tursiops aduncus). Both are typically nearshore species. Two species of sea turtles 

were observed – green (Chelonia mydas) and leatherback (Dermochelys coriacea). All 

were observed exhibiting normal behaviors. 

The following is provided as a summary of marine mammals and sea turtles observed 

during the two nearshore monitoring periods. 

Kekaha: 

16 July 2006: A school of approximately 100 spinner dolphins (Stenella longirostris) are 

observed approximately 300m offshore (0747 hrs). Animals are slowly heading south 

and are being followed by a catamaran. When first vessel leaves, a series of RHIBs and 

catamarans stop and follow animals, one after the other. Animals are last seen at 0826 

hrs approximately 0.5 miles offshore. Behavior overall is slow travel to south, with 

several spins. This is largest group that was seen during the five day period. 

16 July 2006: A turtle (presumed green) is seen surfacing approximately 100m offshore. 

17 July 2006: A school of approximately fifteen spinner dolphins is observed heading 

slowly south (0830 hrs) being followed by a tour catamaran. Dolphins are last observed 

at 0910 hrs. Behavior overall is slow travel to south, with several aerial spins. 

17 July 2006: Green sea turtle is observed approximately 4 m offshore. 

18 July 2006: A small school of ten to fifteen spinner dolphins are observed 

approximately 0.25 miles offshore, with two tour boats (0835 hrs). Dolphins are very 

low in the water and would be very difficult to see without boats as “cue”. Dolphins not 

seen after boats leave at 0845 hrs. 

19 July 2006: Unidentified dolphins, cue is splash and idling tour boat, at horizon (0715 

hrs.). 

19 July 2006: Unidentified dolphins (presumed spinners) observed at southwestern 

horizon splashing, heading north (0858 hrs.). 

19 July 2006: Spinner dolphins observed heading north towards Barking Sands (0922 

hrs.). They continue to north out of view. 

20 July 2006: Spinner dolphins observed in resting mode about 400m off southern shore 

of Kekaha Beach. Group size is approximately 20 animals, and they are milling at 0730 

hrs. At 0745 hrs, they are traveling slowly to the north towards Barking Sands. They 

bowride as a boat approaches and follows them. Dolphins last seen at 0847 hrs. 


B-3

Appendix C 

Mahukona: 

(0730 hrs to 1300 hrs.) 

24 July 2006: Leatherback turtle (D. coriacea) observed approximately 300m offshore. 

Turtle is identified as a leatherback based upon very large carapace size (estimated 5-6 ft 

across) and huge rounded head. Back and head were seen simultaneously at the animal 

breathed. Turtle was observed at the surface for 1-2 minutes then dove (0759 hrs). 

Kapaà Beach Park: 

24 July 2006: Group of approximately 20 bottlenose dolphins (Tursiops aduncus) are 

observed, first seen heading southwest (1630 hrs). A third of the group are calves. 

Animals travel steadily to the SW, except stopping to mill for about 3 minutes near a 

group of shearwaters and tuna feeding on bait fish. Dolphins contour shoreline to the 

south and disappear from view at 1646 hrs. 

Bottlenose dolphins reappear from the south, heading west (1725 hrs). The dolphins are 

much more surface-active during this sighting, porpoising and leaping out of the water. 

At 1749 hrs, after a long dive (5 minutes), they resurface with obvious blows and change 

direction to the southwest and appear to be feeding along the edge of a large aggregation 

of shearwaters, tuna and bait fish. 

25 July 2006: Small turtle (green) observed just offshore (0858 hrs). 

26 July 2006: Small green turtle observed hugging coastline and “riding” the surge (1415 

hrs). 

DISCUSSION AND CONCLUSIONS 

All marine mammals and turtles were observed exhibiting normal behavior. No adverse 

behavior, strandings, or offshore species were observed. 

Land based, stationary monitoring has known deficiencies. The low height of eye above 

water provides a limited distance to the horizon and species identification can be difficult 

as there is no option to approach animals. However, given the purpose of this project, the 

goals were achieved. This monitoring gathered adequate data on the lack of behavioral 

change exhibited by resident groups of spinner dolphins at Kekaha, Kauai and Kohala, 

Hawaii. Additionally, we were able to monitor the length of Kekaha Beach, by foot, for 

stranded or distressed animals. The Kohala coast presented more of a challenge as it was 

comprised of boulder beaches. However, a 4x4 vehicle was utilized to access areas to the 

North (towards the channel) from the monitoring station at Kapaà Beach. 


B-4

Appendix C 

Additionally, anecdotal data collected on interactions between commercial tour 

catamarans and RHIBs might prove to be useful to regulatory agencies such as the State 

of Hawaii and National Oceanographic and Atmospheric Association. 

Date 

2006 

Location 

Time 

(24 

hr) 

Beaufort 

Sea State 

TABLE 1 

Species 

Observations 

7/16 Kekaha 0700 2 Begin watch. Great visibility, 

overcast skies 

Kekaha 0747 S. 

longirostris 

Spinners with catamaran. 

Slowly bowriding on vessel 

(Aladin). Couple of spins 

seen after cat leaves. Located 

about 300m offshore, moving 

south. Group size ~100. 

7/16 Kekaha 0750 S. 

Catamaran leaves dolphins 

longirostris 

7/16 Kekaha 0755 S. 

longirostris 

RHIB runs up to animals and 

follows them 

7/16 Kekaha 0759 S. 

RHIB leaves dolphins 

longirostris 

7/16 Kekaha 0809 S. 

Still heading slowly S 

longirostris 

7/16 Kekaha 0826 Two new RHIBs with S.l., 

about 0.5 mile offshore 

7/16 Kekaha 0850 C. mydas Green turtle seen about 100m 

offshore 

7/16 Kekaha 1230 3 Sea state change 

7/16 Kekaha 1430 4 Occasional rain squalls passing 

over 

7/16 Kekaha 1600 3 Squalls clear. Navy ship seen 

on horizon heading from N 

coast to the S 


7/16 Kekaha 1745 Complete watch 

7/17 Kekaha 0700 3 Begin watch, sunny skies, 

good visibility 

7/17 Kekaha 0745 Two helicopters and 3 Navy 

ships seen on horizon. Helos 

ahead of ships along with three 

small red RHIBs inshore of 

ships 

7/17 Kekaha 0815 Three Navy ships seen N of 

Barking Sands and head SW 


B-5

Appendix C 

Date 

2006 

Location 

Time 

(24 

hr) 

Beaufort 

Sea State 

Species 

7/17 Kekaha 0830 S. 

longirostris 

7/17 Kekaha 0835 S. 

longirostris 

7/17 Kekaha 0850 4 S. 

longirostris 

Observations 

through the channel, one right 

after the other. 

Spinners seen bowriding on 

catamaran. Cat is heading N 

but stops and does u-turn 

through spinners and follows 

them south for ~ 5 min. 

Just as cat leaves dolphins, a 

RHIB goes through them while 

heading N. 

Na Pali Kai III catamaran seen 

doing u-turn and following 

dolphins to S. They stay with 

the dolphins heading S until 

0910 hrs. Few spins from 

dolphins. 

Visibility changes to moderate 

due to higher Beaufort. 

7/17 Kekaha 1015 4 Glare, moderate visibility. 

Have lost sight of dolphins due 

to sea conditions. 

7/17 Kekaha 1053 3=inshore 

4=offshore 

Visibility improves as wind 

dies down. 


7/17 Kekaha 1612 4 C. mydas Turtle seen at surface about 4 

m offshore. 


7/18 Kekaha 0700 1 Begin watch 

7/18 Kekaha 0835 S. 

longirostris 

Small group of spinners (~15 

animals) observed ~.25 miles 

offshore. One RHIB and one 

cat stop with dolphins and 

proceed slowly through them. 

7/18 Kekaha 0845 S. 

longirostris 

Boats leave dolphins and head 

N 

7/18 Kekaha Catamaran seen stopping ~ 0.5 

miles offshore towards N. 

Can’t see dolphins but assume 

that is why they are stopping. 

7/18 Kekaha 1005 3 Still sunny… 

7/18 Kekaha 1700 Cruise ship comes from N, 

heads through channel and 

continues to the S over horizon 


B-6

Appendix C 

Date 

2006 

Location 

Time 

(24 

hr) 

Beaufort 

Sea State 

Species 

Observations 


7/19 Kekaha 0700 1 Begin watch, swell 2-3 ft. 

7/19 Kekaha 0715 Unidentified 

dolphin 

7/19 Kekaha 0858 Unidentified 

dolphin 

7/19 Kekaha 0922 S. 

longirostris 

Catamaran and two RHIBs are 

stopped on horizon. Appear to 

be slowly following marine 

mammals, but other than one 

splash, I cannot identify them 

to species. 

School of dolphins (presumed 

spinners) seen at SW horizon, 

splashing, heading N 

Spinners seen heading N off 

Kekaha. Catamaran comes up 

to them and slowly moves 

through them. Group size ~20. 


7/19 Kekaha 1515 Three red RHIBs head out of 

Portlock heading N through 

channel (we are later told these 

are part of RIMPAC ops). 

7/19 Kekaha 1530 2 Swell 1-2 ft. 

7/19 Kekaha 1644 1 st Navy destroyer enters 

channel. Second one ~1 mile 

behind it. Helo overhead and 

doing sweeps ahead of ships 

(and has been for about an 

hour over the horizon). Ships 

appear to be moving slowly 

through channel. 

7/19 Kekaha 1703 Second ship leaves channel. 

Helo has been dipping sonar 

ahead of 2 nd ship. 1 st ship N of 

Lehua and over horizon. 

7/19 Kekaha 1706 2 nd ship passes Lehua heading 

N and goes over horizon. 

7/19 Kekaha 3 red Navy RHIBs pass 

Kekaha. 


7/20 Kekaha 0700 1 Begin watch with great 

visibility, partly cloudy. 

7/20 Kekaha 0715 S. 

longirostris 

Spinners in resting mode about 

400m offshore, off southern 

shore of beach. Milling 


B-7

Appendix C 

Date 

2006 

Location 

Time 

(24 

hr) 

Beaufort 

Sea State 

Species 

7/20 Kekaha 0730 S. 

longirostris 

7/20 Kekaha 0753 S. 

longirostris 

Observations 

behavior, group size ~20. No 

boats with dolphins, the boats 

appear to not see them. 

Spinners are now just N of 

lifeguard tower heading N. 

Tour boat Makana stops with 

dolphins and they slowly 

bowride. 


7/20 Kekaha 0804 S. 

longirostris 

7/20 Kekaha 0811 S. 

longirostris 

7/20 Kekaha 0814 S. 

longirostris 

7/20 Kekaha 0820 S. 

longirostris 

7/20 Kekaha 0828 S. 

longirostris 

7/20 0840 S. 

longirostris 

Makana still slowly following 

spinners to the N, then S. They 

are really staying with them 

longer than most boats do, 

following the milling dolphins 

back and forth. 

Makana leaves dolphins 

Tour RHIB runs up on 

dolphins, then u-turns and 

follows them. 

As RHIB leaves, catamaran 

“Lucky Lady” comes slowly 

up to them and sits with 

dolphins. 

“Lucky Lady” leaves dolphins 

Another cat on spinners, N of 

Kehaka. Does u-turns and 

runs through them a few times 

at slow speed. 

Cat leaves dolphins, heads N 

7/20 Kekaha 0847 1 S. 

longirostris 

7/20 Kekaha 1234 2 Overcast skies, great visibility 

7/20 Kekaha 1800 Complete watch. Total beach 

monitored with 2-3 beach 

walks daily is 3 miles (includes 

all of Kekaha Beach to 

Barking Sands boundary) 

7/24 Mahukona 0730 2=inshore 

3=offshore 

Begin watch. Walked up to 

point north of harbor for better 

view of channel and Maui. 

Partly cloudy skies, good 

visibility. 


B-8

Appendix C 

Date 

2006 

Location 

Time 

(24 

hr) 

Beaufort 

Sea State 

Species 

Observations 

7/24 Mahukona 0759 D. coriacea Leatherback turtle observed. 

Carapace was 5-6 ft across and 

a huge rounded head, which is 

seen simultaneously during 

surfacing. (There is a kayaker 

offshore of turtle which we 

used for a size comparison). 

Turtle is observed breathing at 

surface for about 1 minute, 

then dives. 

7/24 Mahukona 0951 4=offshore 

3=inshore 

7/24 Kapaà 1330 2=inshore 

Beach 

4=offshore 

Park 

Sea state change 

Change monitoring station to 

Kapaà Beach Park, which is 

just N of Mahukona towards 

Hawi. It offers a better view of 

the channel, Maui and provides 

a protected inshore area with 

better viewing conditions. 

Cloud cover is 90%. 

7/24 Kapaà 1630 T. aduncus Group of ~ 20 bottlenose 

dolphins are observed heading 

SW, about 400m offshore. 

Does not appear to be mixed 

species, however, about 1/3 of 

the group are calves. Group is 

traveling slowly and steadily to 

the SW, except for stopping 

for about 3 minutes near a 

group of shearwaters and tuna 

feeding on bait fish. Group 

stayed about the same distance 

offshore and heads SW out of 

view (at 1646 hrs.) 

7/24 Kapaà 1725 T. aduncus Group of ~20 bottlenose 

dolphins are observed again, 

coming from around the point 

where they were last seen. 

They are heading to the W. 

They are moving more quickly 

this time, porpoising out of the 

water. As they lift heads higher 

to prepare for a dive, several of 


B-9

Appendix C 

Date 

2006 

Location 

Time 

(24 

hr) 

Beaufort 

Sea State 

Species 

Observations 

them flip their tails up. 

Reappear after five minutes 

with very visible blows. 

7/24 Kapaà 1749 T. aduncus Ta change direction to SW and 

appear to be feeding. They are 

working the margin of a large 

school of tuna and shearwaters 

which feeding on bait fish. 

The dolphins behavior includes 

direction change, leaps out of 

the water, and a few tail slaps. 

The group is a little more 

spread out too, than before. 

They continue this behavior 

for about 5 minutes, then 

regroup and head slowly 

offshore to the SW out of 

sight. 

7/24 Kapaà 1800 Complete watch. Drive up 4x4 

road towards Hawi to check 

coastline for any strandings or 

other animals that might be out 

of sight. 

7/25 Kapaà 

Beach 

Park 

0715 2=inshore 

4=offshore 

Begin watch. Three Navy 

ships and one other unid ship 

are observed over horizon 

towards Maui, in the channel. 

They are heading W. 

7/25 Kapaà 0745 Ships have disappeared over 

W horizon 

7/25 Kapaà 0858 C. mydas Small turtle (green) seen just 

off cove, about 100m offshore. 



4=offshore 

7/25 Kapaà 1200 Leave beach park to drive up 

to Upolu Point and down to 

Mookini Heiau and Kam I 

birthplace to monitor other 

boulder beaches closer to 

channel. 

7/25 Kapaà 1300 Return to Kapaà Beach Park 


5=offshore 



B-10

Appendix C 

Date 

2006 

Location 

Time 

(24 

hr) 

Beaufort 

Sea State 

Species 

Observations 

7/25 Kapaà 1830 Complete watch for the day. 


Begin watch, excellent 

3/4offshore 

visibility inshore. Mostly 

sunny skies. 



4=offshore 

7/26 Kapaà 1415 C. mydas Small green turtle observed 

hugging coastline. Observed 

for about 30 minutes riding the 

surge back and forth around 

the rocks. Last seen at 1445 

hrs. Lots of glare inshore. 


5=offshore 

Continues to be lots of glare, 

covering approximately 1/3 of 

viewing range. 

7/26 Kapaà 1800 Complete watch (head to 

airport). 


B-11

Appendix C 

Appendix C 

Results of 2006 RIMPAC Surveys of Marine Mammals 

in Kaulakahi and Alenuihaha Channels 

Final Report Submitted by: 

Joseph R. Mobley, Jr., Ph.D. 

Marine Mammal Research Consultants, Ltd. 

Date: 

August 25, 2006 

October 2007 USWEX EA/OEA C-53

Appendix C 


Page 

Abstract ------------------------------------------------------- 3 

Background --------------------------------------------------- 3 

Method -------------------------------------------------------- 4 

Results --------------------------------------------------------- 6 

Discussion ----------------------------------------------------- 9 

References ----------------------------------------------------- 11 

Appendix ------------------------------------------------------ 12 

Tables 

Table 1: Summary of survey effort and sightings ---------- 6 

Table 2: Summary of species sightings by region ---------- 8 

Figures 

Figure 1: Survey effort for Kaulakahi Channel ------------- 5 

Figure 2: Survey effort for Alenuihaha Channel ------------ 6 

Figure 3: Summary of Beaufort seastate conditions -------- 7 

Figure 4: Kaulakahi Channel sightings ----------------------- 8 

Figure 5: Alenuihaha Channel sightings ---------------------- 9 


2

Appendix C 

Results of 2006 RIMPAC Surveys of Marine Mammals 

in Kaulakahi and Alenuihaha Channels 

Abstract 

A total of six aerial surveys of marine mammals were performed on dates corresponding 

with scheduled dates for “choke point” maneuvers of the “Rim of the Pacific” (RIMPAC) 

joint military exercises in Hawaiian waters. Three surveys were performed in the vicinity 

of the Kaulakahi Channel (between Kauai and Niihau) (July 16, 17 and 20) and three 

were performed in the Alenuihaha Channel (between Hawaii and Maui) (July 24-26). The 

mission of the surveys was to detect, locate and identify all marine mammal species in 

the target areas using methods consistent with modern distance sampling theory. Marine 

mammals were sighted on four of the six surveys, comprising a total of 13 groups. All 

sightings consisted of small to medium-sized odontocetes (toothed cetaceans), including 

one sighting each of bottlenose dolphins, spotted dolphins, Cuvier’s beaked whale, false 

killer whale, unidentified beaked whale and eight sightings of unidentified delphinid 

species. Encounter rates of odontocete sightings (sightings/km surveyed) in this series 

were identical to those seen during earlier survey series (1993-03) albeit at different times 

of the year. No unusual observations (e.g., sightings of stranded or dead animals) were 

noted during the total of ca. 18 hrs of survey effort. 

Background 

During the summer of 2006, The United States Pacific Command hosted the joint “Rim 

of the Pacific Exercises” (RIMPAC) military exercises in the Hawaiian Islands. Due to 

concerns over possible responses of marine mammal species to sonar and other aspects of 

the naval operations (e.g., ICES, 2005), aerial surveys were scheduled for dates before, 

during and after scheduled “choke point” maneuvers. Specifically this involved the 

Kaulakahi Channel, between the islands of Kauai and Niihau, on July 16, 17 and 20; and 

the Alenuihaha Channel, between the islands of Hawaii and Maui, on July 24, 25 and 26. 

The mission of the surveys was to detect, locate and identify all marine mammals in these 

channel areas, as well as to report any unusual behavior, including sightings of stranded 

or dead cetaceans. 

Since the month of July falls outside the normal seasonal residency of humpback whales 

(Jan-Apr) (Mobley 2004), the less abundant odontocete species (toothed cetaceans) were 

the target species in the present survey series. Shallenberger (1981) described 15 

odontocete species as resident in Hawaii. Based on aerial surveys conducted between 

1993-98, Mobley et al. (2000) estimated abundance for 11 odontocete species for the 

waters within 25 nautical miles (nmi) of the major Hawaiian Islands based on surveys 

conducted during Jan-Apr of 1993-98. An updated summary of aerial survey results for 

near-shore Hawaiian waters conducted from 1993-2003 identified a total of 15 

odontocete species (Mobley, unpublished data, Appendix A). Barlow (2006) provided 

abundance estimates for 21 cetacean species, including 18 odontocetes, based on 


3

Appendix C 

shipboard transect surveys conducted in Aug-Nov 2002 in the Hawaiian Exclusive 

Economic Zone (EEZ). 

Method 

Three surveys were performed in each of the Kaulakahi (July 16, 17 and 20) and 

Alenuihaha (July 24, 25, 26) channels for a total of six surveys. Survey protocol was 

based on distance sampling methods, which is the standard accepted approach for 

estimating abundance of free ranging animal populations (Buckland et al. 2001). 

Surveys in both regions followed pre-determined tracklines constructed to optimize area 

sampled within range limits of the aircraft (Figures 1 & 2). For the Kaulakahi Channel 

surveys, tracklines ran mostly north-south and were spaced 7.5 km apart comprising a 

total length of ca 556 km. 1 For the Alenuihaha surveys, tracklines ran from northeast to 

southwest and were spaced 15 km apart and comprised a total length of ca. 740 km. 

Starting longitudes in both regions were randomly chosen per distance sampling 

methodology (Buckland et al. 2001) so that the exact trackline configuration varied 

slightly for each survey. 

The survey aircraft for the first survey (July 16) was a single-engine Cessna 177RG 

Cardinal 1 . For the remaining five surveys a twin-engine Piper PA34 Seneca was used. 

Both aircraft flew at a mean ground speed of 100 knots and an average altitude of 244m 

(800 ft). Two experienced observers made sightings of all marine mammal species, one 

on each side of the aircraft. Sightings were called to a data recorder who noted the 

species sighted, number of individuals, presence or absence of a calf, angle to the 

sighting (using hand-held Suunto clinometers), and any apparent reaction to the aircraft. 

Additionally, GPS locations and altitude were automatically recorded onto a laptop 

computer at 30-sec intervals, as well as manually whenever a sighting was made. 

Environmental data (seastate, glare and visibility) were manually recorded at the start of 

each transect leg and whenever conditions changed. The two data sources (manual and 

computer) were later merged into a single data file. Species identifications were typically 

made by orbiting an initial sighting until sufficient diagnostic features were discernible to 

permit positive identification. When the initial sighting could not be recaptured upon 

orbiting, the species was recorded as “unidentified.” 

1 

Due to PMRF Range Ops on July 16, 2006, flying in the Kaulakahi Channel region was 

not permitted. We therefore surveyed an adjacent region off the central and southwest 

coast of Kauai in order to avoid the warning area on that date. 


4

Appendix C 

Figure 1. Survey effort for Kaulakahi Channel. GPS data (red lines) for surveys 

performed on July 16,17 and 20. Tracklines were 7.5 km apart and extended 

13 km past the 1000 fathom contour. Total transect length was ca. 556 km. 

The tracklines to the south of Kauai were flown on July 16 only, when the 

waters of Kaulakahi Channel were closed due to scheduled operations 

of the Pacific Missile Range Facility (PMRF) at Barking Sands, Kauai. 


5

Appendix C 

Figure 2. Survey effort for Alenuihaha Channel. GPS position data (red lines) 

are shown for July 24-26 surveys. Tracklines were 15 km apart and 

extended 13 km past the 1000 fathom limit. Total trackline distance for 

each survey was approximately 740 km. 

Results 

Overview. The six surveys comprised a total of ca. 18 hrs and ca. 3300 km of linear 

survey effort (Table 1). The number of sightings as well as the ability to identify species 

was generally hampered by poor seastate conditions that prevailed on all but one of the 

survey dates (July 20) (Table 1, Figure 3). Seastate is the primary factor affecting the 

ability to detect marine mammals (Buckland et al. 2001). 

Summary of sightings. Cetacean species were detected on five of the six surveys (Table 

1), including four identified species (bottlenose dolphins, spotted dolphins, false killer 

whales and Cuvier’s beaked whale), one unidentified beaked whale species (likely 

Mesoplodon densirostris) and eight unidentified delphinid species (Table 2, Figures 4 & 

5). All four of the identified species are among those typically seen in nearshore 

Hawaiian waters (Mobley et al. 2000; Shallenberger 1981). No unusual behavior or 

activity (e.g., stranded or dead animals) was observed during the six surveys. 

Encounter rate comparison. One method of normalizing sightings for performing 

comparisons is to calculate encounter rates (groups sighted/km surveyed) (Buckland et al. 


6

Appendix C 

2001). In the present series a total of 13 sightings were made across ca. 3,334 km of 

survey effort which corresponds to an encounter rate of .0004 sightings/km. This rate is 

identical with the encounter rate for all odontocetes combined observed during the 1993- 

2003 survey series for inshore waters around the main Hawaiian Islands during the 

months Jan-Apr (Mobley, unpublished data, Appendix A). Therefore, the densities of 

marine mammal species reported here is identical with that normally seen for the 

Hawaiian Islands, albeit at different times of the year. 

Table 1. Summary of Survey Effort and Sightings 

Region Date No. of 

sightings 

Survey effort 

(hrs) 

Mean Beaufort 

seastate 

Kaulakahi Channel July 16 0 1.25 4.38 

July 17 2 3.96 4.06 

July 20 3 3.08 1.47 

Alenuihaha Channel July 24 1 3.28 4.36 

July 25 5 3.33 4.17 

July 26 2 3.02 4.80 

Total: 13 17.92 

Figure 3. Summary of Beaufort Seastate Conditions. Beaufort seastate is one of the 

main factors affecting the ability to detect marine mammals. Normally, the ability to 

detect drops substantially beyond Beaufort 3. As shown, the majority of survey effort 

occurred in Beaufort 5, whereas the greater number of sightings occurred in Beaufort 2. 


7

Appendix C 

Table 2. Summary of Species Sightings by Region 

Region / Species No. groups No. individuals 

Kaulakahi Channel: 

Spotted dolphins (Stenella attenuata) 1 14 

Unidentified delphinid species 4 21 

Alenuihaha Channel: 

Bottlenose dolphin (Tursiops truncatus) 1 1 

False killer whales (Pseudorca crassidens) 1 4 

Cuvier’s beaked whale (Ziphius cavirostris) 1 1 

Unidentified beaked whale 1 1 

Unidentified delphinid species 4 29 

Figure 4. Kaulakahi Channel sightings. A total of five sightings occurred in the 

Kaulakahi Channel including one pod of spotted dolphins and four of unidentified 

delphinid species. Inner and outer bathymetry lines refer to 100 and 1000 fathom 

contours, respectively. 


8

Appendix C 

Figure 5. Alenuihaha Channel sightings. A total of 8 sightings occurred in the 

Alenuihaha Channel, including one pod of each of the following species: bottlenose 

dolphin, false killer whale, Cuvier’s beaked whale and an unidentified beaked whale 

species (likely Mesoplodon densirostris). Additionally four pods of unidentified 

delphinids were sighted. Inner and outer bathymetry lines refer to the 100 and 1000 

fathom contours, respectively. 

Discussion 

From the total of 13 sightings only four (31%) were positively identified to species. One 

sighting in the Alenuihaha Channel was identified as a beaked whale (likely Blainville’s 

beaked whale, M. densirostris) but was not resighted upon orbiting, thus obviating 

positive species identification. The low rate of species identification was likely due to the 

poor seastate conditions that prevailed on all but one of the six surveys (Table 1, Figure 

3) thereby making it difficult to recapture the sighting when orbiting. 

The sighting of a group of four false killer whales (Pseudorca crassidens) was significant 

given recent concerns over the possible decline in their population around the Hawaiian 

Islands, possibly due to fisheries interactions (Baird and Gorgone 2005). In the 1993-03 


9

Appendix C 

aerial survey series, false killer whales were not seen after 1998 (Mobley, unpublished 

data), so the current sighting is the first aerial sighting since that time, though shipboard 

observations have been recorded (e.g., Barlow 2006). 

Similarly, the sighting of a single Cuvier’s beaked whale (Ziphius cavirostris), also in the 

Alenuihaha Channel, was significant given the fact that previous reports of adverse 

reactions to mid-range sonar primarily involved this species (ICES, 2005). It was sighted 

on 25July when RIMPAC activities were scheduled to occur in the channel, and was 

sighted mid-channel in waters deeper than 1000 fathoms (Figure 5). 

As noted, the encounter rate for sightings in the present survey series (.0004 sightings/km 

surveyed) was identical to that recorded for odontocete species during the 1993-03 aerial 

survey series for the months Jan-Apr (Mobley 2004). This suggests that densities in the 

Kaulakahi and Alenuihaha Channels were no more or less than those normally seen 

throughout Hawaiian waters, albeit at different times of the year. Barlow (2006) 

commented on the low densities of odontocete species noted during 2002 shipboard 

surveys of the Hawaiian Exclusive Economic Zone (EEZ), noting them to be lower than 

most warm-temperate and tropical locations worldwide. He attributed this low density to 

the low productivity of the subtropical gyre that affects Hawaiian waters. 

In conclusion, these surveys provided no evidence of impact of RIMPAC activities on 

resident populations of cetaceans in the Kaulakahi and Alenuihaha Channels. No 

differences in cetacean densities were detected, and no unusual behavior or event (e.g., 

unusual aggregations or near strandings) was observed. This statement should not be 

interpreted as evidence of no impact, merely that no such evidence was detected during 

these 18 hrs of surveys. 

Acknowledgements 

Data reported here were collected under Scientific Collecting Permit No. 642-1536-00 

issued by NOAA Office of Protected Resources to the author. I would like to thank our 

competent crew of observers including Lori Mazzuca, Michael Richlen, Terri Krauska 

and Robert Uyeyama. Thanks also to John Weiser for his superb piloting. 


10

Appendix C 

References 

Baird, R.W. and Gorgone, A.M. (2005). False killer whale dorsal fin 

disfigurements as a possible indicator of long-line fishery interactions in Hawaiian 

waters. Pacific Science, 59:593–601. 

Barlow, J. (2006). Cetacean abundance in Hawaiian waters estimated from a summer/fall 

survey in 2002. Marine Mammal Science, 22:446-464. 

Buckland, S.T., Anderson, D.R., Burnham, K.P, Laake, J.L., Borchers, D.L. and 

Thomas, L. (2001). Introduction to distance sampling: Estimating abundance of 

biological populations. New York: Chapman and Hall. 

International Council for the Exploration of the Sea (ICES) (2005), “Report of the 

Ad-Hoc Group on the Impact of Sonar on Cetaceans.” 50 pp. Available at: 

http://socrates.uhwo.hawaii.edu/SocialSci/jmobley/ICES.pdf 

Mobley, Jr., J. R. (2004). Results of marine mammal surveys on U.S. Navy 

underwater ranges in Hawaii and Bahamas. Final Report to Office of Naval Research, 27 

pp. Available as downloadable pdf file at: 

http://socrates.uhwo.hawaii.edu/SocialSci/jmobley/ONRfinal.pdf 

Mobley, Jr., J.R., Spitz, S.S., Forney, K.A., Grotefendt, R.A. and Forestell, P.H. 

(2000). Distribution and abundance of odontocete species in Hawaiian waters: 

Preliminary results of 1993-98 aerial surveys. Report to Southwest Fisheries Science 

Center, Administrative Report 

LJ-00-14C. 26 pp. Available as downloadable pdf file at: 

http://socrates.uhwo.hawaii.edu/SocialSci/jmobley/SWFSC.pdf 

Mobley, Jr., J.R., Spitz, S.S., Grotefendt, R, Forestell, P.H., Frankel, A.S. and 

Bauer, G.A. (2001). Abundance of humpback whales in Hawaiian waters: Results of 

1993-2000 aerial surveys. Report prepared for the Hawaiian Islands Humpback Whale 

National Marine Sanctuary, Nov. 26, 2001. 

Shallenberger, E.W. (1981). The status of Hawaiian cetaceans. Final report to the U.S. 

Marine Mammal Commission, Washington, DC. Report No. MMC-77/23. 79 pp. 


11

Appendix C 

Appendix A 

1993 - 2003 Hawaiian Islands Aerial 

Survey Results 

No. No. 

Species Name pods indiv. 

Humpback whale (Megaptera novaeangliae) 2352 3907 

Spinner dolphin (Stenella longirostris) 52 1825 

Spotted dolphin (Stenella attenuata) 31 1021 

Short-finned pilot whale (Globicephala 

73 769 

macrorhynchus) 

Melon-headed whale (Peponocephala 

6 770 

electra) 

Bottlenosed dolphin (Tursiops truncatus) 54 492 

False killer whale (Pseudorca crassidens) 18 293 

Sperm whale (Physeter macrocephalus) 23 106 

Rough-toothed dolphin (Steno bredanensis) 8 90 

Blainville's beaked whale (Mesoplodon 

9 32 

densirostris) 

Pygmy or dwarf sperm whale (Kogia spp.) 4 28 

Striped dolphin (Stenella coeruleoalba) 1 20 

Pygmy killer whale (Feresa attenuata) 2 16 

Cuvier's beaked whale (Ziphius cavirostris) 7 13 

Risso's dolphin (Grampus griseus) 1 8 

Killer whale (Orcinus orca) 1 4 

Fin whale (Balaenoptera physalus) 1 3 

Unid. Dolphin 96 452 

Unid. Stenella spp. 11 196 

Unid. Whale 28 39 

Unid. beaked whale 9 23 

Unid. Cetacean 14 27 

Totals: 2801 10134 


12

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