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FINAL PROGRAMMATIC BIOLOGICAL OPINION ON U.S. NAVY ACTIVITIES IN THE HAWAII RANGE COMPLEX 2008-2013
whales will migrate from different foraging areas to a single wintering area. In either case, humpback whales appear
to form “open” populations; that is, populations that are connected through the movement of individual animals.
NORTH PACIFIC OCEAN. <strong>NMFS</strong>’ Stock Assessment Reports recognize four “stocks” of humpback whales in the North
Pacific Ocean, based on genetic and photo-identification studies: two Eastern North Pacific stocks, one Central
North Pacific stock, and one Western Pacific stock (Hill and DeMaster 1998). The first two of these “stocks” are
based on where these humpback whales winter: the central North Pacific “stock” winters in the waters around
Hawai'i while the eastern North Pacific “stock” (also called the California-Oregon-Washington-Mexico stock)
winters along coasts of Central America and Mexico. However, Calambokidis et al. (1997) identified humpback
whales from Southeast Alaska (central North Pacific), the California-Oregon-Washington (eastern North Pacific),
and Ogasawara Islands (Japan, Western Pacific) groups in the Hawai'ian Islands during the winter; humpback
whales from the Kodiak Island, Southeast Alaska, and British Columbia groups in the Ogasawara Islands; and
whales from the British Columbia, Southeast Alaska, Prince William Sound, and Shumagin-Aleutian Islands groups
in Mexico.
Herman (1979), however, presented extensive evidence and various lines of reasoning to conclude that the
humpback whales associated with the main Hawai’ian Islands immigrated to those waters only in the past 200 years.
Winn and Reichley (1985) identified genetic exchange between the humpback whales that winter off Hawai'i and
those that winter off Mexico (with further mixing on feeding areas in Alaska) and suggested that the humpback
whales that winter in Hawai'i may have emigrated from wintering areas in Mexico. Based on these patterns of
movement, we conclude that the various “stocks” of humpback whales are not true populations or, at least, they
represent populations that experience substantial levels of immigration and emigration.
A “population” of humpback whales winters in an area extending from the South China Sea east through the
Philippines, Ryukyu Retto, Ogasawara Gunto, Mariana Islands, and Marshall Islands (Rice 1998). Based on whaling
records, humpback whales wintering in this area have also occurred in the southern Marianas through the month of
May (Eldredge 1991). There are several recent records of humpback whales in the Mariana Islands, at Guam, Rota,
and Saipan during January through March (Darling and Mori 1993; Eldredge 1991, 2003; Taitano 1991). During the
summer, whales from this population migrate to the Kuril Islands, Bering Sea, Aleutian Islands, Kodiak, Southeast
Alaska, and British Columbia to feed (Angliss and Outlaw 2007, Calambokidis 1997, 2001).
Between 2004 and 2006, an international group of whale researchers coordinated their surveys to conduct a
comprehensive assessment of the population structure, levels of abundance, and status of humpback whales in the
North Pacific (Calambokidis et al. 2008). That effort identified a total of 7,971 unique individuals from photographs
taken during close approaches. Based on the data collected during that study, Calabmokidis et al. (2008) estimated
the rates of exchange among humpback whales in different areas in the Hawai'ian Islands that are presented in Table
4
NORTH ATLANTIC OCEAN. In the Atlantic Ocean, humpback whales aggregate in four feeding areas in the summer
months: (1) Gulf of Maine, eastern Canada, (2) west Greenland, (3) Iceland and (4) Norway (Katona and Beard
1990, Smith et al. 1999). The principal breeding range for these whales lies from the Antilles and northern
Venezuela to Cuba (Winn et al. 1975, Balcomb and Nichols 1982, Whitehead and Moore 1982). The largest
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