NMFS Biological Opinion on U.S. Navy training ... - Govsupport.us

FINAL PROGRAMMATIC BIOLOGICAL OPINION ON U.S. NAVY ACTIVITIES IN THE HAWAII RANGE COMPLEX 2008-2013
5.1.1 Surface Vessel Traffic
Most of the activities the U.S. Navy proposes to conduct in the Hawai'i Range Complex involve some level of
activity from surface vessels, submarines, or both. The U.S. Navy’s 2002 Programmatic Environmental Assessment
stated that Rim of the Pacific exercises typically involve between 20 and 60 surface vessels moving at differing
speeds in the Hawai'i Range Complex (U.S. Navy 2002) and 27 U.S. ships participated in the 2008 RIMPAC
exercises. Undersea Warfare Exercises typically involve 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. Unit-level or intermediate-level
anti-submarine warfare tracking exercises include ships, fixed wing aircraft, helicopters, torpedo targets, 1 to 10
submarines, and weapons recovery boats or helicopters.
Vessel traffic associated with the proposed training exercises actually represents a suite of stressors or stress regimes
that pose several potential hazards to endangered and threatened species in the Hawai'i Range Complex. First, the
size and speed of these surface vessels pose some probability of collisions between marine mammals and sea turtles.
Second, this amount of traffic represents an acute or chronic source of disturbance to marine animals in the Hawai'i
Range Complex, although it is not clear what environmental cue marine animals might respond to: the sounds of
waters being displaced by the ships, the sounds of the ships’ engines, or a combination of environmental cues
surface vessels produce while they transit.
Probability of Collisions. Given the speeds at which these vessels are likely to move, they pose potential hazards to
marine mammals. The Navy’s operational orders for ships (and aircraft) that are underway are designed to prevent
collisions between surface vessels participating in naval exercises and endangered whales that might occur in the
action area. These measures, which include observers on the bridge of ships, requirements for course and speed
adjustments to maintain safe distances from whales, and having any ship that observes whales to alert other ships in
the area, have historically been effective measures for avoiding collisions between surface vessels and whales.
Although the probability of a collision seems fairly small given the measures that are in place, 20 to 60 additional
surface vessels engaged in training maneuvers in the Action Area poses some risk of disturbing large whales that
might occur in the Action Area. Particularly when that traffic is placed in the context of animals that are likely to
have had extensive prior experience with existing levels of vessel traffic associated with inter-island transportation,
commercial ship traffic, whale-watching vessels, leisure cruises, and research vessels that were discussed in the
Environmental Baseline of this <strong>Opinion</strong>.
Disturbance. Studies of interactions between surface vessels and marine mammals have demonstrated that surface
vessels represent a source of acute and chronic disturbance for marine mammals (Au and Green 1990, Au and
Perryman 1982, Bain et al. 2006, Bauer 1986, Bejder 1999, 2006a, 2006b; Bryant et al. 1984, Corkeron 1995, Erbé
2000, Félix 2001, Goodwin and Cotton 2004, Hewitt 1985, Lemon et al. 2006, Lusseau 2003, 2006; Lusseau and
Bejder 2007, Magalhães et al. 2002, Ng and Leung 2003, Nowacek et al. 2001, Richter et al. 2003, 2006; Scheidat
et al. 2004, Simmonds 2005, Watkins 1986, Williams and Ashe 2007, Williams et al. 2002, 2006a, 2006b; Würsig et
al. 1998). Specifically, in some circumstances, marine mammals respond to vessels with the same behavioral
repertoire and tactics they employ when they encounter predators.
159