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
term behavioral responses, which included cessation of feeding, resting, or social interactions. Several studies have
demonstrated short-term effects of disturbance on humpback whale behavior (Baker et al. 1983, Bauer and Herman
1986, Hall 1982, Krieger and Wing 1984), but the long-term effects, if any, are unclear or not detectable. Carretta et
al. (2001) and Jasny et al. (2005) identified the increasing levels of anthropogenic noise as a habitat concern for
whales and other cetaceans because of its potential effect on their ability to communicate.
Surface shipping is the most widespread source of anthropogenic, low frequency (0 to 1,000 Hz) noise in the oceans
(Simmonds and Hutchinson 1996). The Navy estimated that the 60,000 vessels of the world’s merchant fleet
annually emit low frequency sound into the world’s oceans for the equivalent of 21.9 million days, assuming that 80
percent of the merchant ships at sea at any one time (U.S. Navy 2001). The radiated noise spectrum of merchant
ships ranges from 20 to 500 Hz and peaks at approximately 60 Hz. Ross (1976) has estimated that between 1950 and
1975 shipping had caused a rise in ambient ocean noise levels of 10 dB. He predicted that this would increase by
another 5 dB by the beginning of the 21 st century. NRC (1997) estimated that the background ocean noise level at 100
Hz has been increasing by about 1.5 dB per decade since the advent of propeller-driven ships.
Michel et al. (2001) suggested an association between long-term exposure to low frequency sounds from shipping
and an increased incidence of marine mammal mortalities caused by collisions with shipping. At lower frequencies,
the dominant source of this noise is the cumulative effect of ships that are too far away to be heard individually, but
because of their great number, contribute substantially to the average noise background.
US Navy Activities. Navy Exercises. Since 1971 4 , the U.S. Navy has conducted the biennial Rim of the Pacific
exercises. These exercises, which historically have lasted for about a month, have involved forces from various
nations on the Pacific Rim including Australia, Canada, Chile, Japan, and the Republic of Korea. We have limited
information on the particular components of those exercises since their inception, but we assume that most of those
exercises involved many of the components that are part of contemporary Rim of the Pacific Exercises (see
Description of the Proposed Action), although sonar systems and ordnance have evolved and changed over time.
We have limited information on the timing and nature of Rim of the Pacific Exercises prior to 2002 and we have no
information on their potential effects on endangered and threatened marine animals in the Hawai'i Range Complex
prior to 2006, when we started to consult with the U.S. Navy on the exercises. Between June and July 2006, the
U.S. Navy conducted Rim of the Pacific exercises in the Hawai'i Range Complex. Based on the U.S. Navy’s 7
December 2006 After-Action Report, over the 15 calendar days of the 2006 RIMPAC (U.S. Navy 2006c), hullmounted
mid-frequency sonars were employed for a total of 472 hours (with 8 hours of transmission lost to comply
with shut-down protocols required by a Marine Mammal Protection Act permit). Over the 15 calendar day of the
2006 RIMPAC, active and passive sonobuoys were deployed for 115 hours (which does not translate to 115 hours of
sonar transmissions because some of the sonobuoys were deployed but were not transmitting).
4
Previous biological opinions on the 2006 Rim of the Pacific Exercises and the Undersea Warfare Exercises reported that
Rim of the Pacific Exercises had occurred in the Hawaii Range Complex since 1968. U.S. Navy historians have since
verified that these exercises began in 1971.
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