1999 

 OUR LIVING OCEANS 



Pups 



(X 1.000) 



Figure 22-2 



Northern fur seal pup counts 

 from the Pribilof Islands, 

 1970-96, 



St. Paul Island 



St Geotge Island 



Year 



Minimum Population Estimate 



Using the population estimate (N) ot 

 1 ,002, S I (i and a CV of 0.2 to account for the cor- 

 rection factor, N for the eastern Pacific stock oi 



mm 



northern tur seals is 848,539 animals. 



Current Population Trend 



The Alaska population ot northern fur seals 

 recovered to approximatelv 1 ■2'S million animals 

 in 1974, alter the killing ot temales was termi- 

 nated in 1968. The population then began to de- 

 crease, with pup pr<:)dtiction declining at a rate ot 

 6.5-7.8% per year into the 1980's; the total stock 

 estimate in 1983 was 877,000. Annual pup pro- 

 duction on St. Paul Island has remained relativcK' 

 stable since 1981 (Figure 22-2), indicating that 

 stock size has not changed much in recent years. 

 The most recent stock estimates prior to 1 996 were 

 984,000 in 1992, and 1.01 million in ]')>)(). I'he 

 northern for seal was designated as depleted un- 

 der the MMPA in 1988 because population levels 

 had declined to less than 50'Mi ot levels observed 

 in the late 1950's, and there was no compelling 

 evidence that carrying capacity (K) had changed 

 substantially since the late 1950's. Under the 

 MMPA, this stock will remain listed as depleted 

 until population levels reach at least the lower limit 

 ot its optimum sustainable population ((iO"ii ot 

 K). 



Status of Stock 



The PBR tor the eastern Pacific stock ot north- 

 ern fijr seals is 18,244 animals. The estimated an- 

 nual level ot total human-caused mortality and 

 serious injury is less than 2,000 seals, and thus 

 does not exceed its PBR. The eastern Pacific stock 

 of the northern for seal is classified as a strategic 

 stock because it is designated as depleted under 

 the MMPA. 



BOWHEAD WHALE: 

 WESTERN ARCTIC STOCK 



Stock Definition 



and Geographic Range 



Bowhead whales are distributed in seasonally 

 ice-covered waters ot the Arctic and near-Arctic, 

 generally north ot 54°N and south ot 75"N in the 

 Western Arctic Basin. Small stocks occur in the 

 Sea ot Okhotsk, Davis Strait, Hudson Bav, and 

 Spitsbergen, but only a tew tens to a tew hundreds 

 are found in each ot these stocks. The largest rem- 

 nant population IS the western Arctic stock which 

 migrates from wintering areas (November to 

 March) in the northern Bering Sea, through the 

 Chukchi Sea in the spring (March through June), 

 to the Beaufort Sea where thev spend niticli of the 

 summer (mid May through September) before 

 rettirning to the Bering Sea in the autumn (Sep- 

 tember through November). 1 he bowhead spring 

 migration follows fractures in the sea ice around 

 the coast ot Alaska, generally in the shear zone 

 between the shorefast ice and the mobile polar pack 

 ice. There is evidence ot whales following each 

 other, even when their route does not take advan- 

 tage of large ice-free areas. As the whales travel 

 east past Point Barrow, Alaska, their migration is 

 somewhat ttmneled between the shoreline and the 

 polar pack ice, making for an optimal location 

 from which to study this stock. Most of the year, 

 bowhead whales are closely associated with sea ice. 

 Only during the summer is this population in rela- 

 tively ice-free waters in the southern Beaufort Sea. 

 an area often exposed to industrial activity related 

 to pctroletim exploration. 



234 



