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
Table 11. Estimated number of times whales of the different species might have accumulate energy that is equivalent to
2
>173, 173 -195, and 195 - 215 dB rms for 1 second during the 2006 Rim of the Pacific Exercise (from U.S. Navy 2006)
Species
Estimated
Abundance
Estimated No. of Exposure Events
173 - 195 dB 195 - 215 dB > 173
Fin whale ~ 174 61 3 64
Sei whale ~ 77 27 1 28
Sperm whale ~ 7,000 1,417 34 1,451
Exposure Estimates Produced by this Approach
The model the Navy used for the 2006 Rim of the Pacific exercise and which formed the foundation for <strong>NMFS</strong>’ 2006
<strong>Opinion</strong> on those exercises only estimate the probability of fin, sei, and sperm whales being exposed to active sonar
associated with the 2006 RIMPAC exercise. The Navy did not model humpback whales in 2006 because the Rim of
the Pacific Exercises occur in July, when humpback whales are not in waters of the Hawai’ian Islands. This
approach to estimating the number of endangered and threatened marine mammals that might be “taken” as a result
of being exposed to active sonar during the 2006 Rim of the Pacific Exercises produced the following results
(Table:11).
FIN WHALES. The simulations the Navy conducted for the 2006 RIMPAC exercise identified 61 instances in which fin
whales might accumulate energy that is equivalent to between 173 and 195 dB during the 2006 RIMPAC exercise (a
total of 64 instances in which fin whales might accumulate energy equivalent to more than 173 dB). Based on our
analyses of those estimates, <strong>NMFS</strong>’ 2006 <strong>Opinion</strong> assumed that 42 of these instances involved a single, individual fin
whale that would accumulate energy equivalent to between 173 and 195 dB on one occasion; another 8 instances in
which individual fin whales would accumulate this energy equivalent on two occasions; and one instance in which
individual fin whales would accumulate this energy equivalent on three occasions.
The Navy’s simulations also identified 3 instances in which fin whales might accumulate energy equivalent to 195 –
215 dB. Based on our analyses of those estimates, <strong>NMFS</strong>’ 2006 <strong>Opinion</strong> assumed that 2 of these instances would
involve a single, individual fin whale that would accumulate energy equivalent to between 173 and 195 dB on one
occasion; once instance in which a single, individual fin whale would accumulate this energy equivalent on three
occasions.
The fin whales that might have been exposed to the 2006 RIMPAC exercise, particularly mid-frequency active sonar
transmissions and ship traffic associated with those exercises, would have represented individuals from the
Hawai’ian population (or “stock”). <strong>NMFS</strong>’ 2006 <strong>Opinion</strong> assumed that any age or gender might be exposed to those
received levels.
SEI WHALES. The simulations the Navy conducted for the 2006 RIMPAC exercise identified 27 instances in which sei
whales might have accumulated energy equivalent to between 173 and 195 dB. Based on our analyses of those
estimates, <strong>NMFS</strong>’ 2006 <strong>Opinion</strong> assumed that 18 of these instances might involve an individual sei whale that would
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