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

COMPTUEX/JTFEX EA/OEA Final Appendix AThe sperm whale was reported to be rare over the continental shelf of the Southern California Bight, butabundant directly offshore of the Southern California Bight (Bonnell and Dailey, 1993). During the 1991and 1993 NMFS ship-based surveys, sperm whales were more abundant farther offshore and farther souththan they were in the Southern California Bight. There are widely scattered sightings of sperm whales indeep waters of the SOCAL Range Complex in the warm-water period, and few sightings in the cold-waterperiod (Fig. A-9). No sperm whales were sighted during the 1998–1999 NMFS aerial surveys of theSCIRC (Carretta et al., 2000).The mean size of 21 groups sighted in the Point Mugu Sea Range was 5.6; nine of those groups were ofsingle animals (primarily adult males), and the largest group encountered was 21 (U.S. Navy, 1998).These estimates are likely low because little time was spent observing groups.Pygmy and Dwarf Sperm WhalesThese two species of small whales are distributed widely in the world's oceans, but they are poorly known(Caldwell and Caldwell, 1989). Their small size, non-gregarious nature, and cryptic behavior makepygmy whales (Kogia breviceps) and dwarf sperm whales (Kogia sima) difficult to observe. The twospecies are also difficult to distinguish when sighted at sea, and are often jointly categorized as Kogia spp.Neither species of Kogia is listed as endangered under the ESA or considered depleted under the MMPA.The minimum population estimate for the California/Oregon/Washington stock of the pygmy spermwhale is 119 (CV=0.67), and there is no information available to estimate the population size of the dwarfsperm whale off the Pacific coast of the U.S (Carretta et al., 2005).Dwarf and pygmy sperm whales are sighted primarily along the continental shelf edge and over deeperwaters off the shelf (Hansen et al. 1994; Davis et al. 1998). However, along the U.S. west coast, sightingsof the whales have been rare, although that is likely a reflection of their pelagic distribution and small sizerather than their true abundance (Carretta et al., 2002). Several studies have suggested that pygmy spermwhales live mostly beyond the continental shelf edge, whereas dwarf sperm whales tend to occur closer toshore, often over the continental shelf (Rice, 1998; Wang et al., 2002; MacLeod et al., 2004). Barros etal. (1998), on the other hand, suggested that dwarf sperm whales might be more pelagic and dive deeperthan pygmy sperm whales.Another suggestion is that the pygmy sperm whale is more temperate, and the dwarf sperm whale moretropical, based at least partially on live sightings at sea from a large database from the eastern tropicalPacific Ocean (Wade and Gerrodette, 1993). There, the pygmy sperm whale was not seen in truly tropicalwaters south of the southern tip of Baja California, but the dwarf sperm whale was common in thosewaters. This idea is also supported by the distribution of strandings in South American waters (Muñioz-Hincapié et al., 1998). Also, in the western tropical Indian Ocean, the dwarf sperm whale was much morecommon than the pygmy sperm whale, which is consistent with this hypothesis (Balance and Pitman,1998).Cuvier’s Beaked WhaleCuvier’s beaked whale (Ziphius cavirostris) is not listed as endangered under the ESA, and theCalifornia/Oregon/Washington stock is not considered to be strategic under the MMPA. The minimumpopulation estimate for the California/Oregon/Washington stock is 1,121 (CV=0.68) individuals (Carrettaet al., 2005).Little is known about the habitat preferences of any beaked whale. Based on current knowledge, beakedwhales normally inhabit deep ocean waters (>2,000 m) or continental slopes (200–2,000 m), and onlyrarely stray over the continental shelf (Pitman, 2002). Cuvier’s beaked whale generally is sighted inwaters >200 m deep, and is frequently recorded at depths >1,000 m (Gannier, 2000; MacLeod et al.,2004). They are commonly sighted around seamounts, escarpments, and canyons. MacLeod et al. (2004)A-29 February 2007