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

COMPTUEX/JTFEX EA/OEA Final Chapter 3minimum population size for the California/Oregon/Washington Stock is 149 (CV=1.02; Carretta et al.,2005).Distribution—The range of the short-finned pilot whale in the eastern North Pacific extends from thetropics to the Gulf of Alaska. However, sightings north of Point Conception are uncommon (Forney,1994). Prior to the 1982–1983 El Niño event, short-finned pilot whales were commonly seen off southernCalifornia, with an apparently resident population around Santa Catalina Island (Dohl et al., 1981). Afterthe El Niño event, they virtually disappeared from the region, and few sightings were made from 1984 to1992. The reason for the decrease in numbers is unknown (Heyning et al., 1994b), but the El Niño eventapparently disrupted their distribution pattern, and they have not returned as residents to waters offsouthern California (Forney, 1994). Short finned pilot whales are found in the SOCAL OPAREAthroughout the year (Forney, 1994).Pilot whales are deep divers; the maximum dive depth measured is 971 m (Baird, personalcommunication). Pilot whales feed primarily on squid, but also take fish (Bernard and Reilly, 1999).Pilot whales are not generally known to prey on other marine mammals; however, records from the ETPsuggest that the short-finned pilot whale does occasionally chase, attack, and may eat dolphins duringfishery operations (Perryman and Foster, 1980), and they have been observed harassing sperm whales inthe Gulf of Mexico (Weller et al., 1996).Acoustics—Short-finned pilot whale whistles and clicks have a dominant frequency range of 2 to 14 kHzand a source level of 180 dB re 1 Pa-m (Fish and Turl, 1976; Ketten, 1998). There are no publishedhearing data available for this species.Sperm Whale (Physeter macrocephalus)Status—The sperm whale is listed as endangered under the ESA and the California/Oregon/WashingtonStock is considered depleted and strategic under the MMPA. The available data suggest that sperm whaleabundance has been relatively stable in California waters since 1979 (Barlow, 1994), but there isuncertainty about both the population size and the annual mortality rates. There is a minimum populationestimate of 885 (CV=0.41) for the California/Oregon/Washington Stock based on ship-based surveysduring summers of 1991 and 1993 (Carretta et al., 2005). Sperm whale abundance in the easterntemperate North Pacific Ocean is estimated to be 32,100 and 26,300 by acoustic and visual detectionmethods, respectively (Barlow and Taylor, 2005).Distribution—Sperm whales show a strong preference for deep waters (Rice, 1989), especially areaswith high sea-floor relief. Sperm whale distribution is associated with waters over the continental shelfedge, over the continental slope, and into deeper waters (Hain et al., 1985; Kenney and Winn, 1987;Waring and Finn, 1995; Gannier, 2000; Gregr and Trites, 2001; Waring et al., 2001). However, in someareas, such as off New England, on the southwestern and eastern Scotian Shelf, and in the northern Gulfof California, adult males are reported to quite consistently use waters with bottom depths