MARINE MAMMAL COMMISSION — Annual Report for 1991 



during the coming field season, but that use of alter- 

 native sampling and census techniques {e.g., alternate 

 year or triennial censuses of indicator groups, remote 

 sensing, and aerial photogrammetry) be pursued to 

 allow shifting more funds and staff time to tasks 

 directly contributing to recovery; (2) membership of 

 the Recovery Team be expanded to include additional 

 behavioral expertise, a physical oceanographer, and a 

 representative of the Fish and Wildlife Service; 

 (3) officials involved in inspecting facilities maintain- 

 ing captive monk seals be augmented to include 

 marine mammal experts; and (4) support be provided 

 to continue regular meetings of an interagency work- 

 ing group formed as a result of the Commission's pro- 

 gram review to coordinate efforts to clean up Tern 

 Island and repair its seawall. With respect to the 

 interagency working group, the Corps of Engineers 

 convened the group soon after the November 1991 

 program review to discuss the range of issues affect- 

 ing restoration of the seawall on Tern Island. 



With regard to closing the Coast Guard's LORAN 

 station on Kure Atoll in 1992, the Conmiission recom- 

 mended in its letter that the Service complete consul- 

 tations with the Coast Guard on the effects of activi- 

 ties associated with closing the station. Among the 

 needs and activities of concern are the complete 

 removal of the solid waste dump on the island, 

 demolition of some of the buildings, dismantling of 

 equipment, and removal of all hazardous materials 

 associated with generators and other equipment at the 

 station. To ensure that such work is carried out with 

 minimal effect on the atoll's seal population, the 

 Commission recommended that the Service place an 

 observer on the island to monitor and, as necessary, 

 provide advice on measures to protect seals during the 

 principal work period to dismantle and remove 

 equipment. 



At the end of 1991, the Commission looked 

 forward to providing continued advice and assistance 

 to the many agencies whose cooperation is so impor- 

 tant to the success of the Hawaiian monk seal recov- 

 ery program. It also looked forward to the results of 

 the January 1992 Hawaiian Monk Seal Recovery 

 Team meeting and the Service's reply to its 20 De- 

 cember 1991 recommendations. 



Steller Sea Lion 

 (Eumetopias jubatus) 



Steller or northern sea lions inhabit coastal areas 

 along the rim of the North Pacific Ocean from the 

 Channel Islands in southern California through the 

 Gulf of Alaska and Aleutian Islands to northern 

 Hokkaido, Japan. In the United States, Steller sea 

 lions are most abundant in the Aleutian Islands and 

 Gulf of Alaska. 



Available information indicates that Steller sea 

 lions numbers are declining substantially throughout 

 most of their range. Recent censuses of major rook- 

 eries and haulouts in the western Gulf of Alaska and 

 eastern Aleutian Islands in the United States and in the 

 Kuril Islands in Russia indicate declines in some areas 

 of up to 90 percent over the past 30 years. The 

 declines have occurred principally since the mid- 

 1980s. Between 1985 and 1989, for example, the 

 number of sea lions counted in the eastern Aleutian 

 Islands declined by more than 70 percent. A sum- 

 mary of Steller sea lion counts in the United States, 

 Canada, and the former Soviet Union is given in 

 Table 3. 



The cause or causes of the declines are uncertain. 

 Natural factors, such as predation by sharks and killer 

 whales, parasites, disease, and natural changes in 

 environmental conditions, may have influenced the 

 population. Likewise, there have been effects result- 

 ing from human-caused factors, such as subsistence 

 harvesting by Alaska Natives, mortality incidental to 

 commercial fishing activities, commercial over-exploi- 

 tation of important prey species, the release of toxic 

 pollutants, entanglement in marine debris Oargely lost 

 or discarded fishing gear), disturbance by boats and 

 aircraft, and the deliberate shooting of sea lions as 

 well as discharge of firearms at or near rookeries and 

 haulout sites. In addition, commercial hunting, which 

 ceased in the United States when the Marine Mammal 

 Protection Act was passed in 1972, may have been 

 responsible for at least part of the earlier observed 

 decline. 



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