MARINE MAMMAL COMMISSION - Annual Report for 1998 



commercial harvests were stopped and only a much 

 smaller subsistence harvest by Aleut Natives on the 

 Pribilof Islands continued. Because of the magnitude 

 of the decline prior to the early 1980s, the Pribilof 

 Islands fur seal population was designated as depleted 

 under the Marine Mammal Protection Act in 1988. 



Although causes of the population decline in the 

 1970s remain puzzling, research indicates that it was 

 related to an increase in mortality of juvenile fur seals 

 during their first few years of life. Among the more 

 plausible factors thought to have been involved are 

 entanglement in marine debris, incidental take in high 

 seas driftnet fisheries in the North Pacific Ocean, 

 long-term environmental change, and reduced prey 

 availability. Effects of disease and parasites are 

 poorly understood but also may be factors. Causes 

 not thought to be significant include lingering effects 

 of the commercial harvest of subadult males before 

 1985, emigration, and predation. Failure of the 

 population to recover since the early 1980s also is 

 puzzling. It may be related to the continuing effects 

 of entanglement in marine debris, environmental 

 change, and reduced prey. 



Subsistence Harvest 



Before 1985 Aleut residents of St. George and St. 

 Paul Islands used a portion of the commercial fur seal 

 harvest for food and other purposes. Since then, 

 these needs have been met by a comparatively small 

 subsistence harvest of subadult male fur seals taken 

 between June and August using methods similar to 

 those of past commercial harvests (Table 5). The 

 subsistence harvest is regulated by the National 

 Marine Fisheries Service pursuant to the Fur Seal Act 

 and the Marine Mammal Protection Act. 



Initially regulations required that, before each 

 annual harvest began, the Service was to estimate the 

 upper and lower harvest levels likely to meet the 

 annual subsistence needs of Aleuts on the Pribilof 

 Islands. When the estimated lower level was reached, 

 harvesting was suspended until it could be determined 

 how many additional fur seals were needed. Harvest 

 levels are now estimated for three-year periods, with 

 the most recent period beginning in 1997. For 1997, 

 1998, and 1999, the Service has projected that the 

 subsistence harvest levels for St. Paul Island will be 



1,645 and 2,000 fur seals, the same as those for the 

 previous three-year period. The lower bound of 

 estimated subsistence requirements for St. George 

 Island during this period was increased from 281 to 

 300 seals; the upper limit of 500 seals was unchanged. 



In 1998 the total subsistence harvest was 1,553 fur 

 seals, consisting of 256 animals harvested on St. 

 George Island and 1,297 animals on St. Paul Island. 



Research Activities in 1998 



In response to recommendations by the Marine 

 Mammal Commission and a provision added to the 

 Marine Mammal Protection Act in 1988, the National 

 Marine Fisheries Service developed and in 1993 

 adopted a conservation plan for northern fur seals. 

 The plan's primary purpose is to identify and guide 

 research and management actions. Among other 

 things, the plan identifies research needed to explain 

 why the population has failed to recover to former 

 levels and to continue monitoring the status and trends 

 of fur seal populations. In the first two years after 

 adopting the plan, funding by the Service was suffi- 

 cient to do little more than monitor the population. 



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