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
Atlantic, they winter from the edge of sea ice south to the Gulf of Mexico and the West Indies. In the eastern
Atlantic, they winter from southern Norway, the Bay of Biscay, and Spain with some whales migrating into the
Mediterranean Sea (Gambell 1985).
In the Southern Hemisphere, fin whales are distributed broadly south of 50° S in the summer and migrate into the
Atlantic, Indian, and Pacific Oceans in the winter, along the coast of South America (as far north as Peru and Brazil),
Africa, and the islands in Oceania north of Australia and New Zealand (Gambell 1985).
Fin whales are common off the Atlantic coast of the United States in waters immediately off the coast seaward to the
continental shelf (about the 1,000-fathom contour). In this region, they are tend to occur north of Cape Hatteras
where they accounted for about 46 percent of the large whales observed in surveys conducted between 1978 and
1982. During the summer months, fin whales in this region tend to congregate in feeding areas between 41°20'N and
51°00'N, from shore seaward to the 1,000-fathom contour.
In the Atlantic Ocean, Clark (1995) reported a general southward pattern of fin whale migration in the fall from the
Labrador and Newfoundland region, south past Bermuda, and into the West Indies. The overall distribution may be
based on prey availability, and fin whales are found throughout the action area for this consultation in most months
of the year. This species preys opportunistically on both invertebrates and fish (Watkins et al. 1984). They feed by
filtering large volumes of water for the associated prey. Fin whales are larger and faster than humpback and right
whales and are less concentrated in nearshore environments.
Population Structure
Fin whales have two recognized subspecies: Balaoptera physalus physalus (Linnaeus 1758) occurs in the North
Atlantic Ocean while B. p. quoyi (Fischer 1829) occurs in the Southern Ocean. Globally, fin whales are sub-divided
into three major groups: Atlantic, Pacific, and Antarctic. Within these major areas, different organizations use
different population structure.
In the North Atlantic Ocean, the International Whaling Commission recognizes seven management units or “stocks”
of fin whales: (1) Nova Scotia, (2) Newfoundland-Labrador, (3) West Greenland, (4) East Greenland-Iceland, (5)
North Norway, (6) West Norway-Faroe Islands, and (7) British Isles-Spain-Portugal. In addition, the population of
fin whales that resides in the Ligurian Sea, in the northwestern Mediterranean Sea is believed to be genetically
distinct from other fin whales populations (as used in this <strong>Opinion</strong>, “populations” are isolated demographically,
meaning, they are driven more by internal dynamics — birth and death processes — than by the geographic
redistribution of individuals through immigration or emigration. Some usages of the term “stock” are synonymous
with this definition of “population” while other usages of “stock” do not).
In the North Pacific Ocean, the International Whaling Commission recognizes two “stocks”: (1) East China Sea and
(2) rest of the North Pacific (Donovan, 1991). However, Mizroch et al. (1984) concluded that there were five
possible “stocks” of fin whales within the North Pacific based on histological analyses and tagging experiments: (1)
East and West Pacific that intermingle around the Aleutian Islands; (2) East China Sea; (3) British Columbia; (4)
Southern-Central California to Gulf of Alaska; and (5) Gulf of California. Based on genetic analyses, Berube et al.
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