NMFS Biological Opinion on U.S. Navy training ... - Govsupport.us

FINAL PROGRAMMATIC BIOLOGICAL OPINION ON U.S. NAVY ACTIVITIES IN THE HAWAII RANGE COMPLEX 2008-2013
of sperm whales have been recorded throughout the year off Oahu (Thompson and Friedl 1982). Twenty-one sperm
whales were sighted during aerial surveys conducted in Hawai’ian waters conducted from 1993 through 1998. Sperm
whales sighted during the survey tended to be on the outer edge of a 50 - 70 km distance from the Hawai’ian Islands,
indicating that presence may increase with distance from shore. However, from the results of these surveys, <strong>NMFS</strong>
has calculated a minimum abundance of sperm whales within 46 km of Hawai’i to be 43 individuals (Forney et al.
2000).
Southern Ocean
Sperm whales south of the equator are generally treated as a single “population,” although the International Whaling
Commission divides these whales into nine different divisions that are based more on evaluations of whaling
captures than the biology of sperm whales (Donovan 1991). Several authors, however, have argued that the sperm
whales that occur off the Galapagos Islands, mainland Ecuador, and northern Peru are geographically distinct from
other sperm whales in the Southern Hemisphere (Rice 1977, Wade and Gerrodette 1993, and Dufault and Whitehead
1995).
Threats to the Species
NATURAL THREATS. Sperm whales are hunted by killer whales (Orcinus orca), false killer whales (Pseudorca
crassidens), and short-finned pilot whales (Globicephala melas; Arnbom et al. 1987, Palacios and Mate 1996, Rice
1989, Weller et al. 1996, Whitehead 1995). Sperm whales have been observed with bleeding wounds their heads and
tail flukes after attacks by these species (Arnbom et al. 1987, Dufault and Whitehead 1995). In October 1997, 25
killer whales were documented to have attacked a group of mature sperm whales off Point Conception, California
(personal communication from K Roberts cited in Perry et al. 1999) and successfully killing one of these mature
sperm whales. Sperm whales have also been reported to have papilloma virus (Lambertson et al. 1987).
Studies on sperm whales in the North Pacific and North Atlantic Oceans have demonstrated that sperm whales are
infected by calciviruses and papillomavirus (Smith and Latham 1978, Lambertsen et al. 1987). In some instances,
these diseases have been demonstrated to affect 10 percent of the sperm whales sampled (Lambertsen et al. 1987).
ANTHROPOGENIC THREATS. Three human activities are known to threaten sperm whales: whaling, entanglement in
fishing gear, and shipping. Historically, whaling represented the greatest threat to every population of sperm whales
and was ultimately responsible for listing sperm whales as an endangered species. Sperm whales were hunted all
over the world during the 1800s, largely for its spermaceti oil and ambergris. Harvesting of sperm whales subsided
by 1880 when petroleum replaced the need for sperm whale oil (Whitehead 2003).
The actual number of sperm whales killed by whalers remains unknown and some of the estimates of harvest
numbers are contradictory. Between 1800 and 1900, the International Whaling Commission estimated that nearly
250,000 sperm whales were killed globally by whalers. From 1910 to 1982, another 700,000 sperm whales were
killed globally by whalers (IWC Statistics 1959-1983). These estimates are substantially higher than a more recent
estimate produced by Caretta et al. (2005), however, who estimated that at least 436,000 sperm whales were killed
by whalers between 1800 and 1987. Hill and DeMaster (1999) concluded that about 258,000 sperm whales were
harvested in the North Pacific between 1947 and 1987 by commercial whalers. They reported that catches in the
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