Chapter III — Species of Special Concern 



merit theory predicted that, after an initial decline in 

 fur seal numbers, pup production, and pup survival 

 would increase as the population attempted to compen- 

 sate for animals removed by the harvest. Therefore 

 beginning in 1956 some female as well as juvenile 

 male fur seals were taken an effort to increase popula- 

 tion productivity. In 1957 the four signatories to the 

 former treaty signed the Interim Convention for the 

 Conservation of North Pacific Fur Seals, under which 

 land-based harvests were again managed and the take 

 of both adult females and juvenile males continued. 



Under the harvest strategy the population began to 

 decline as expected, but instead of rebounding a few 

 years later, it continued to decline. The take of 

 females was therefore stopped in 1968. As expected, 

 the population continued to decline through 1970 due 

 to a residual effect of the female harvest, and then 

 began to increase early in the 1970s. But from 1974 

 through the early 1980s, it again declined at a rate of 

 about eight percent per year for reasons that could no 

 longer be attributed to the female harvest. By 1983 

 its number had dropped to about 877,000 animals, 

 less than half its size in the early 1950s. 



Throughout this period the interim convention was 

 extended by a series of protocols until 1984 when it 

 lapsed. At that time management authority for fur 

 seals in the United States reverted to domestic authori- 

 ty under the Fur Seal Act of 1966 and the Marine 

 Mammal Protection Act. Under these acts, com- 

 mercial harvests were stopped and only a much 

 smaller subsistence harvest by Aleut Natives on the 

 Pribilof Islands continued. Since the early 1980s the 

 Pribilof Islands' fur seal herd has remained relatively 

 stable, but because of the magnitude of its decline 

 prior to that time the population was designated as 

 depleted under the Marine Mammal Protection Act in 

 1988. Based on a 1994 census (the most recent 

 survey), its current size is estimated at about 

 1,014,000 animals, or about 1,019,000 animals if 

 Bogoslof Island fur seals are included. 



While causes of the population decline in the 1970s 

 remain puzzling, research indicates that it was related 

 to an increase in mortality of juvenile seals during 

 their first few years of life. Among the more plausi- 

 ble factors thought to have been involved are entan- 

 glement in marine debris, incidental take in high seas 



driftnet fisheries in the North Pacific Ocean, long- 

 term environmental change, and reduced prey avail- 

 ability. Effects of disease and parasites are poorly 

 understood but also may have been a factor. Causes 

 not thought to be significant include lingering effects 

 of the commercial harvest of females in the 1960s, the 

 commercial harvest of sub-adult males prior to 1985, 

 emigration, and predation. Failure of the population 

 to recover since the early 1980s is equally puzzling 

 but may be related to the continuing effects of marine 

 debris, environmental change, and reduced prey. 



Subsistence Harvest 



Before 1985 Aleut residents of St. George and St. 

 Paul Islands in the Pribilof Islands used a portion of 

 the commercial fur seal harvest for food and other 

 purposes. Since then, these needs have been met by 

 a much smaller subsistence harvest of sub-adult male 

 seals taken between June and August using methods 

 similar to past commercial harvests. The subsistence 

 harvest is managed by the National Marine Fisheries 

 Service pursuant to regulations authorized by the Fur 

 Seal Act and the Marine Mammal Protection Act. 



The regulations require that, before the actual 

 harvests begin, the Service estimate the upper and 

 lower harvest levels likely to meet the annual subsis- 

 tence needs of Aleut residents on the Pribilof Islands. 

 Whenever the estimated lower level is reached, har- 

 vesting is suspended until it can be determined how 

 many additional seals are needed. In 1994 the Service 

 projected that subsistence needs for 1994, 1995, and 

 1996 could be met by annual harvests of between 281 

 and 500 fur seals on St. George Island and between 

 1,645 and 2,000 fur seals on St. Paul Island. 



In 1995 the total subsistence harvest was 1,525 fur 

 seals, including 260 animals on St. George and 1,265 

 animals on St. Paul. As shown in Table 5, the 1995 

 harvest was slightly lower than recent harvests. When 

 the Service requested public comments on its project- 

 ed subsistence harvest needs for the years 1994 to 

 1996, some commenters suggested that the estimates 

 were too high because recent butchering methods used 

 by Aleut sealers did not fully utilize all suitable parts 

 of seal carcasses. Data on butchering techniques 

 employed in the 1995 harvest indicate seal carcasses 

 were fully utilized. 



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