Marine Resources Assessment for the Marianas Operating ... - SPREP

AUGUST 2005 FINAL REPORT
1.0 INTRODUCTION
The Navy’s COMPACFLT contracted this MRA to initiate collection of data and information concerning the
protected and commercial marine resources found in U.S. Pacific Fleet military ranges and training areas
located in the waters off of Guam and the Commonwealth of the Northern Mariana Islands (CNMI). For
the purposes of this MRA, the military areas assessed will be considered as one unit that is hereafter
referred to as “the Marianas MRA study area” or more simply as “the study area.”
1.1 PURPOSE AND NEED
The goal of this MRA is to describe and document the marine resources in the Marianas MRA study area,
including both protected and commercial marine species. This MRA provides a compilation of the most
recent data and information on the occurrence of these resources in the study area. A synopsis of
environmental and habitat data and in-depth discussions of the species of concern found in the study
area and surrounding region are included. The locations of EFH and other areas of interest, such as
MMAs and SCUBA diving sites, are also addressed in this assessment. In addition, this report identifies
data gaps and prioritizes recommendations for future research in the study area.
Beyond the Navy’s immediate mission in the study area is the Department of Defense’s (DoD) mission to
prevent pollution, protect the environment, and protect natural, historic, and cultural resources (DoN
1999). The assembled information in this MRA will serve as a baseline from which the Navy may evaluate
future actions and consider adjustments to training exercises or operations in order to mitigate potential
impacts to protected and commercial marine resources. This assessment will contribute to the Fleet’s
Integrated Long-Range Planning Process and represents an important component in the Fleet’s ongoing
compliance with U.S. federal mandates that aim to protect and manage resources in the marine
environment. All species and habitats that are potentially affected by the Navy’s maritime exercises and
are protected by U.S. federal resource laws or executive orders are considered in this assessment.
A search and review of relevant literature and data was conducted to provide information on the relevant
features of the marine environment (coastal and oceanic), the occurrence patterns of protected species,
and the distribution of EFHs and fishing activities in the study area and vicinity. To describe the physical
environment and habitats at Guam and the CNMI, physiographic, bathymetric, geologic, hydrographic,
and oceanographic data for the region are presented and locations of benthic communities (e.g.,
live/hardbottom and coral reefs), artificial habitats (e.g., artificial reefs and shipwrecks), and submerged
aquatic vegetation are identified. All available sighting, stranding, satellite tracking, nesting, and critical
habitat data for marine mammals and sea turtles were compiled and interpreted to predict the occurrence
patterns of these protected species in the study area and vicinity. Seasonal variations in occurrence
patterns have been identified, mapped, and described along with the likely causative factors (behavioral,
climatic, or oceanographic). Characteristics of these species, such as their behavior and life history,
relevant to the evaluation of potential impacts of Navy operations are included. Also reviewed were the
locations of EFHs, fishing activities, U.S. maritime boundaries, commercially navigable waterways,
MMAs, and SCUBA diving sites. This report summary of the marine resources occurring in the Marianas
MRA study area is provided in both paper and electronic form.
1.2 LOCATION OF STUDY AREA
The Marianas MRA study area is located in the western North Pacific Ocean more than 1,600 kilometers
(km) south of Japan and 2,400 km east of the Philippines (Figure 1-1). The CNMI is a chain of 16 islands
that extends 730 km from Farallon de Pajaros in the north to Rota in the south, and encompasses a total
land area of 510 square kilometers (km 2 ). The largest islands in the CNMI are Saipan, Rota, and Tinian,
which account for 65 percent (%) of the Commonwealth’s land area and are home to 99% of its
population. The U.S. Territory of Guam lies immediately to the south of the CNMI, and is the largest and
southernmost island in the Mariana Islands archipelago (PBEC 1985). The Marianas MRA study area
includes military training areas and ranges in the near vicinity of the following islands: Guam, Tinian, and
Farallon de Medinilla (FDM). At Guam, four distinct areas were assessed: 1) Apra Harbor; 2) Agat Bay
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