Islands), the western North Pacific (Kurile Islands), and the 

 Okhotsk Sea (Robben Island) do not contribute significantly 

 to this population. Two additional rookeries in the eastern 

 North Pacific Ocean are off southern California on San 

 Miguel Island and nearby Castle Rock near the southern limit 

 of the fur seal's range. The San Miguel colony of fur seals was 

 discovered in 1968 with about 100 fur seals (Castle Rock col- 

 ony was discovered in 1972). By 1979 this San Miguel-Castle 

 Rock colony had grown to more than 3,000 animals. 



The U.S.S.R. manages rookeries on islands in the western 

 North Pacific Ocean used by about 485,000 seals that return 

 annually to breed on the Commander Islands (Medny and Ber- 

 ing Islands) in the western Bering Sea, Robben (Tyuleni) Is- 

 land off Sakhalin Island in the Okhotsk Sea, and on a few of 

 the Kurile Islands. Recoveries of tagged animals have shown 

 that seals from the eastern and western breeding islands do in- 

 termix to some small extent at sea and on the breeding islands. 

 Figure 1 shows the general ocean distribution and breeding is- 

 lands of northern fur seals in the eastern and western North 

 Pacific. 



GENERAL DISTRIBUTION AT SEA 



Northern fur seals occupy the subarctic waters of the North 

 Pacific Ocean extending southward to the California-Mexican 

 border (lat. 32°N) in the eastern Pacific and to about the mid- 

 dle of Honshu Island, Japan, (lat. 36°N) in the western 

 Pacific. Very few fur seals have been sighted south of these 

 latitudes. The 57,927 fur seal sightings shown in Figure 2 are 

 from sighting data obtained primarily from pelagic fur seal 

 cruises with supplemental data from other sources to provide a 

 picture of fur seal distribution at sea. Sightings of seals in the 

 western North Pacific Ocean area are primarily from the Japa- 

 nese pelagic fur seal research cruises (1958-78), the National 

 Marine Fisheries Service (NMFS) Dall's Porpoise Program 

 (1978-80), and from salmon research cruises of U.S. vessels 

 (1955-72). Sightings of seals in the eastern North Pacific Ocean 

 area are primarily from Canadian and U.S. pelagic fur seal 



cruises (1958-74); other sightings are from NMFS programs 

 which include the Platforms of Opportunity Program (POP), 

 Outer Continental Shelf Environmental Assessment Program 

 (OCSEAP), and Dall's Porpoise Program. 



Some northern fur seals are found throughout their range in 

 the eastern North Pacific Ocean in nearly all months of the 

 year with periods of peak abundance varying by time and area. 

 Many immature seals of both sexes remain at sea during the 

 first year or two of life and do not return to their island of 

 birth until ages 2 or 3 yr. Most fur seals spend about half the 

 year at sea (November through May-June) and the remainder 

 (July-October) on and around their home islands during the 

 breeding season. 



Fur seals are most frequently seen from about 70 to 130 km 

 from land and usually in greatest numbers along the continen- 

 tal shelf and slope throughout their range primarily because of 

 abundant food resources in this area. Most fur seals are still on 

 or near the Pribilof Islands in October but by the end of 

 November only about 30% or less of the population remains 

 near the Pribilof Islands at a time when the first seals have 

 completed their North Pacific (Gulf of Alaska) crossing and 

 are beginning to appear off the coasts of southeastern Alaska, 

 British Columbia, and Washington. During research cruises 

 off California, Oregon, and Washington, the first seals were 

 sighted on 5 December and on 25 and 27 November, respec- 

 tively. 



From January to March, fur seals are found along the con- 

 tinental shelf and slope, entering coastal waters in pursuit of 

 prey, from the Gulf of Alaska south to California. Fur seals 

 continue to increase in abundance during December and Janu- 

 ary off Washington and California. In February and March, 

 seals are most abundant from California to Sitka, Alaska. The 

 numbers of fur seals wintering off California reach a peak dur- 

 ing late January through March and decrease as they begin 

 their northward migration starting in late March. Most seals 

 have left this area by early June. 



In April fur seals are widely dispersed from Kodiak Island, 

 Alaska, to California with the population reaching its peak in 



- 60 O0N 



Figure 1. — The general ocean distribution and breeding islands of the northern fur seal (modified from: Fiscus, C. H. 1980. 

 Range of the northern fur seal. Unpubl. rep., 7 p. Natl. Mar. Mammal Lab., Northwest and Alaska Fish. Cent., Natl. 

 Mar. Fish. Serv., NOAA, 7600 Sand Point Way NE., Seattle, WA 98115). 



