Composite Training Unit Exercises and Joint Task ... - Govsupport.us

COMPTUEX/JTFEX EA/OEA Final Chapter 4operations with active sonar, therefore, short-finned pilot whales that migrate into the operating areawould be detected by visual observers. Implementation of protective measures and probability ofdetecting groups of short-finned pilot whales reduces the likelihood of exposure.There is little information on the acoustic abilities of short finned pilot whales, but they produce whistlesin the range of 0.5 to at least 20 kHz with the dominant frequencies at 2 to 14 kHz (Richardson et al.,1995). There is no information on the echolocation frequencies of short finned pilot whales, but longfinned pilot whales produce echolocation clicks in the range of 6 to 11 kHz (Au, 1993). Whalers aroundthe waters of the Faroe Islands use boat echo-sounders (15 to 200 kHz) to drive long finned pilot whalesin to the shore (Bloch, 1991). Like many other species of odontocetes, long finned pilot whales willlikely dive and move away from the active sonar ship.The Navy therefore concludes that the proposed action would not affect annual rates of recruitment orsurvival for short-finned pilot whales, and would not have a significant impact on this species and stock.Spinner Dolphin (Stenella longirostris)Spinner dolphins are not found in California but inhabit the warm waters of Central America, therefore,they are a possible summer visitor to southern California waters. The spinner dolphin is not listed asendangered under the ESA, and is not considered to be depleted or strategic under the MMPA. Spinnerdolphins were not included in the marine mammal acoustic effects analysis.Striped Dolphin (Stenella coeruleoalba)The striped dolphin is not listed as endangered under the ESA, and the California/Oregon/WashingtonStock is not considered to be depleted or strategic under the MMPA. The best estimate of the size of theCalifornia/Oregon/Washington Stock is 13,934 (CV=0.53; Carretta et al., 2004). The modeling effortsand harassment analysis for mid-frequency active sonar estimate that no Level A harassment of stripeddolphins would occur. The analysis estimates that up to 1,554 incidents of non-injurious behavioralharassment and 72 incidents of non-injurious physiological (Level B harassment) may be experienced bystriped dolphins on annual basis (Table 4.3-28). Six striped dolphins could be exposed to impulsivenoises or pressures from underwater detonations that could cause TTS but would not cause physicalinjury.Table 4.3-28. Raw Annual Acoustic Model Output of Striped DolphinBehavioral173-