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

COMPTUEX/JTFEX EA/OEA Final Chapter 3Island in 1997. Distribution at sea is unknown (Reeves et al., 1992), but Guadalupe fur seals may migrateat least 600 km from the rookery sites, based on pelagic observations of individuals in the SCB (Seagars,1984). The Guadalupe fur seal is expected to be very rare in the SOCAL Range Complex, except perhapsfor a small area around Guadalupe Island. Researchers suspect that water temperature and preyavailability would affect fur seal movements to the north. With cooler water they would stay south tofeed and with warmer water they would move north to follow prey. There was a warming of the EasternNorth Pacific (Pacific Decadal Oscillation) from the mid 1970s to the mid 1990s but now it is currently ina cooling trend. Except during El Niño conditions, Guadalupe fur seals would stay to the north duringcooler periods (Boeuf and Crocker, 2005).Acoustics—In-air sounds of Guadalupe fur seals include barks, roars, and coughs; few details are known(Peterson et al., 1968). There is no published information on the hearing range of the Guadalupe fur sealalthough it is most likely similar to other fur seals species. Northern fur seals produce underwater clicks,and in-air bleating, barking, coughing, and roaring sounds (Schusterman, 1978; Richardson et al., 1995).The underwater hearing range of the northern fur seal ranges from 0.5 Hz to 40 kHz (Moore andSchusterman, 1987; Babushina et al., 1991) and the threshold is 50 to 60 dB re 1 μPa-m (Moore andSchusterman, 1987). The best underwater hearing occurs between 4 and 17 to 28 kHz (Moore andSchusterman, 1987; Babushina et al., 1991). The maximum sensitivity in air is at 3 to 5 kHz (Babushinaet al., 1991), after which there is an anomalous hearing loss at around 4 or 5 kHz (Moore andSchusterman, 1987; Babushina, 1999).The species is not expected to be present in the SOCAL OPAREA; therefore, density information can notmeaningfully be calculated and this species is not described in Appendix A. Additional discussion ofGuadalupe fur seal is provided by NMFS in their Biological Opinion for the JTFEX/COMPTUEXPreferred Alternative (2007).Northern Fur Seal (Callorhinus ursinus)Status—The northern fur seal is not listed under the ESA. The range of the northern fur seal extendsfrom southern California north to the Bering Sea, and west to the Okhotsk Sea and the Sea of Japan(Antonelis and Fiscus, 1980). Two separate stocks of northern fur seals are recognized within U.S.waters: the Eastern Pacific Stock and the San Miguel Island Stock (Barlow et al., 1998). The San MiguelIsland Stock, which occurs north of the SOCAL Range Complex, is not considered depleted or strategicunder the MMPA. A minimum population estimate for the San Miguel Island Stock is 4,190 (Carretta etal., 2005).Distribution—The Eastern Pacific Stock spends May–November in northern waters and at northernbreeding colonies. In late November, females and young begin to arrive in offshore waters of California,with some animals moving south into continental shelf and slope waters. Maximum numbers are found inwaters from 34ºN to 42ºN during February–April; most are found offshore of the continental slope. Byearly June, most seals of the eastern Pacific Stock have migrated back to northern waters (Antonelis andFiscus, 1980). Adult males from the Eastern Pacific Stock generally migrate only as far south as the Gulfof Alaska (Kajimura, 1984). The Eastern Pacific Stock of northern fur seal is classified as a strategicstock because it is designated as depleted under the MMPA. The minimum population estimate for theEastern Pacific Stock is 751,714 (Angliss and Lodge, 2004).Northern fur seals were made locally extinct at San Miguel Island during the mid-1800s by commercialsealing operations. After an absence of over 100 years, they re-colonized the island during the late 1950sor early 1960s (DeLong, 1982). The population at San Miguel Island has been increasing steadily since1972, except for a drop in numbers during the El Niño events of 1982 (Barlow et al., 1998) and 1997–3-61 February 2007