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

COMPTUEX/JTFEX EA/OEA Final Chapter 4hearing from 0.5 to 160 kHz with maximum sensitivity between 29 and 123 kHz Kastelein et al., 2003).There is no information on the response of striped dolphins exposed to anthropogenic sounds butbottlenose dolphins exposed to mid-frequency sonar sounds in a laboratory setting had an increase inheart rate (Miksis et al., 2001) and a change in their trained behaviors such as moving away from or notreturning to the sound source station (Schlundt et al., 2000, Finneran et al., 2005).The exposures depicted in Table 4.3-28 would not necessarily occur to 1,626 different individuals. Thesame individual could experience behavioral disruption more than once over the course of a year,particularly if the animal is resident in the area of the range. Thus, the estimated number of individualstriped dolphins experiencing Level B harassment may be fewer than 1,626. Mitigation measures detailedin Chapter 5 would further reduce the potential for any effect on striped dolphins. The Navy thereforeconcludes that the proposed action would not affect annual rates of recruitment or survival for stripeddolphins, and would not have a significant impact on this species and stock.Modeling results indicate that striped dolphins are not reasonably expected to be exposed to acousticenergy in excess of onset-TTS from single, point source detonations. The Level A zone of influence ofthe largest detonations (MK 83) extends to 1,000 yards from the source. Implementation of protectivemeasures listed in Chapter 5 will ensure effective mitigation such that this species would not be exposedto incidental Level A or Level B harassment.Ziphiid Beaked WhalesThe Longman’s beaked whale is not listed as endangered under the ESA, and the Hawaiian Stock is notconsidered to be strategic under the MMPA. The population estimate for the Hawaiian Stock is 766(CV=1.05) individuals (Carretta et al., 2005). The modeling efforts and harassment analysis for midfrequencyactive sonar estimate that no Level A harassment of Ziphiid beaked whales would occur. Theanalysis estimates that up to 49 incidents of non-injurious behavioral and 3 non-injurious physiologicalharassment (Level B harassment) may be experienced by Ziphiid beaked whales on annual basis (Table4.3-29). Although modeling predicts non-injurious Level B exposures, all beaked whale exposures arecounted as Level A. No Ziphiid beaked whales would be exposed to impulsive noise or pressures fromunderwater detonations that would cause TTS or physical injury.Table 4.3-29. Raw Annual Acoustic Model Output of Ziphiid Beaked WhaleBehavioral173-