Scientists interested in standards for anthropogenic noise impacts on marine mammals may wish to consider the default standards that may be established by the Environmental Impact Statement for the US Navy's Undersea Warfare Training Range, the Draft of which is currently open for public comment until 30 January 2006. The outcome of this process is likely to influence the broader acoustic criteria now being developed by the National Marine Fisheries Service.
190 dB re 1 µPa²-s is considered the threshold of significant behavioral disturbance for all cetaceans (DEIS page 4.3-24). This impact threshold was derived from subjective observations of "altered behavior" during Temporary Threshold Shift (TTS) experiments with captive dolphins and belugas at the US Navy's SPAWAR lab, and is used to define Marine Mammal Protection Act Level B harassment. All dB values are as received, and include a factor for duration of signal.
190 dB re 1 µPa²-s is the received level at which beaked whales are considered behaviorally disturbed, and as a special case, considered potentially injured, MMPA Level A Harassment. This value is defined as receiving a single sonar ping, is based on selective data, and is considered conservative (4.3-30 through 32). Do you agree with the DEIS discussion of various theories and data relating to induced behaviors leading to injury in beaked whales? Do you know of additional references and data that might apply?
195 dB re 1 µPa²-s is defined as the onset of TTS in all cetaceans, and establishes MMPA Level B physiological harassment. The single value onset-TTS for all cetaceans was derived from very few experiments with highly conditioned captive bottlenose dolphins and belugas (4.3-6. and 12+).
215 dB re 1 µPa²-s is the threshold for Permanent Threshold Shift (PTS), the onset of injury for all cetaceans (expect beaked whales), and MMPA Level A Harassment. PTS was extrapolated from the onset-TTS assumptions and research on terrestrial mammals including humans (4.3-15 to 18).
The DEIS concludes, from acoustic modeling, that right whales will not be affected by the activities at the Preferred Alternative, Site A, in the Cherry Point OPAREA between Cape Fear and Cape Lookout, North Carolina, USA. One of several ramifications is that ESA Section 7 consultation with NMFS will not include right whales unless another alternative is selected The DEIS concludes that "Navy vessels are not likely to adversely affect North Atlantic Right Whales," and that "the proposed action will not adversely modify or destroy any critical habitats, nor will the action jeopardize the continued existence of any listed species" (3.2-23 to 24. 4.3-13, and 44 to 45).
The DEIS redefines some parameters without references or substantiation. For example "The definition of physiological effect and behavioral effect used here are specific to this OEIS/EIS and should not be confused with more global definitions applied to the field of biology" (4.3-3+). Page numbers given here may not be the only location for conclusions, which may be fragmented or stated in different ways. Calculated harassment distances are not given for all sonar sources, but with a threshold value of 190dB the DEIS assumes harassment within only a few meters of any source, often only within a narrow arc. Bowriding dolphins are not considered threatened by exposure.
Comments on the DEIS for the Undersea Warfare Training Range must be postmarked by 30 January 2006. Comments must be sent to: Naval Facilities Engineering Command Atlantic, Attn: Mr. Keith Jenkins (Code EV21KJ), 6506 Hampton Boulevard, Norfolk, VA 23508, Fax: 757-322-4894. The USWTR DEIS may be downloaded from http://projects.earthtech.com/USWTR/ .
Please consider whatever time you can give to this as a gift to whales.
Thank you,
William W. Rossiter
President
Cetacean Society International
P.O.Box 953, Georgetown, CT 06829 USA
ph 203-770-8615, fx 860-561-0187
[EMAIL PROTECTED]
www.csiwhalesalive.or
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