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
(i)
(ii)
Areas of at least 1,000-meter (m) depth near a shoreline where there is a rapid
change in bathymetry on the order of 1,000 m to 6,000 m occurring across a
relatively short horizontal distance (e.g., 5 nautical miles [nm]).
Cases for which multiple ships or submarines (≥ 3) operating MFA sonar in the
same area over extended periods of time (≥ 6 hours) in close proximity (≤ 10 nm
apart).
(iii) An area surrounded by land masses, separated by less than 35 nm and at least 10
nm in length, or an embayment, wherein events involving multiple ships/subs (≥
3) employing MFA 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).
2.0 MFA/HFA Sonar Use associated with training events in the Humpback Whale Cautionary Area
Humpback whales migrate to the Hawai’ian Islands each winter to rear their calves and mate. Data indicate that,
historically, humpback whales have clearly concentrated in high densities in certain areas around the Hawai’ian
Islands. <strong>NMFS</strong> has reviewed the Navy’s data on MFA sonar training in these dense humpback whale areas since June
2006 and found it to be rare and infrequent. While past data is no guarantee of future activity, it documents a history
of low level MFA sonar activity in dense humpback areas. In order to be successful at operational missions and
against the threat of quiet, diesel-electric submarines, the Navy has, for more than 40 years, routinely conducted ASW
training in Major Exercises in the waters off the Hawai’ian Islands, including the Humpback Whale National Marine
Sanctuary. During this period, no reported cases of harmful effects to humpback whales attributed to MFA sonar use
have occurred. Coincident with this use of MFA sonar, abundance estimates reflect an annual increase in the
humpback whale stock (Mobley 2001, 2004).
<strong>NMFS</strong> and the Navy explored ways of affecting the least practicable impact (which includes a consideration of
practicality of implementation and impacts to training fidelity) to humpback whales from exposure to MFA sonar.
Proficiency in ASW requires that Sailors gain and maintain expert skills and experience in operating MFA sonar in
myriad marine environments. Exclusion zones or restricted areas are impracticable and adversely impact MFA sonar
training fidelity. The Hawai’ian Islands, including areas in which humpback whales concentrate, contain unique
bathymetric features the Navy needs to ensure Sailors gain critical skills and experience by training in littoral waters.
Sound propagates differently in shallow water. No two shallow water areas are the same. Each shallow water area
provides a unique training experience that could be critical to address specific future training requirements. Given
the finite littoral areas in the Hawai’i Islands area, maintaining the possibility of using all shallow water training
areas is required to ensure Sailors receive the necessary training to develop and maintain critical MFA sonar skills. In
real world events, crew members will be working in these types of areas and these are the types of areas where the
adversary’s quiet diesel-electric submarines will be operating. Without the critical ASW training in a variety of
different near-shore environments, crews will not have the skills and varied experience needed to successfully
operate MFA sonar in these types of waters, negatively affecting vital military readiness.
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