MARINE MAMMAL COMMISSION — Annual Report for 1991 



The most likely causes of the recent declines are 

 incidental take by trawl fisheries (more than 20,000 

 animals between 1966 and 1988), commercial exploi- 

 tation of important prey species, particularly walleye 

 pollock (Theragra chalcogramma), and shooting by 

 fishermen to defend their gear or catch. Sea lions in 

 the central Gulf of Alaska seem to be growing more 

 slowly and reaching sexual maturity later in life, 

 suggesting that decreased food availability may be at 

 least one of the causes of the declines. At present, 

 one cannot say whether the apparent nutritional 

 problem is due to natural or human-related causes or 

 a combination of the two. Ecologically sound man- 

 agement dictates that, unless it is determined that the 

 declines are due to natural factors, efforts should be 

 focused on eliminating or minimizing human-caused 

 mortality, injury, and habitat degradation. 



Protective Actions 



In May 1988, the National Marine Fisheries 

 Service published an advance notice of proposed 

 rulemaking to designate the Steller sea lion as depleted 

 under the Marine Mammal Protection Act. By letter 

 of 8 July 1988, the Commission recommended that 

 the Service proceed immediately with the proposed 

 designation and that a conservation plan, similar to a 

 recovery plan for endangered and threatened species, 

 be developed to guide management and research 

 efforts. TTie 1988 amendments to the Marine Mam- 

 mal Protection Act subsequently directed the Service 

 to prepare a Steller sea lion conservation plan by 31 

 December 1990. By letter of 6 December 1988, the 

 Commission advised the Service that much of the 

 information and analyses needed to prepare the plan 

 were available in the Steller sea lion chapter of the 

 Commission's 1988 Alaska species reports (see 

 Appendix B, Lentfer 1988), and that the Service 

 therefore should be able to complete the conservation 

 plan well before the 31 December 1990 date set by 

 Congress. 



The Service, in 1989, failed to prepare a conserva- 

 tion plan or publish a proposed rule to designate the 

 Steller sea lion as depleted. On 21 November 1989, 

 the Environmental Defense Fund petitioned the 

 Service for an emergency listing of the Steller sea lion 

 as endangered under the Endangered Species Act. By 



letter of 20 December 1989, the Commission recom- 

 mended that the Service act immediately on the 

 petition and that it complete and distribute a draft 

 Steller sea lion conservation plan by March 1990. 

 The Commission wrote the Service again on 31 

 January 1990 to stress the importance of acting 

 promptly on the Environmental Defense Fund's 

 petition and completing a recovery plan or conserva- 

 tion plan for Steller sea lions. At that time, the 

 Commission also recommended that the Service take 

 steps to prepare proposed rules listing the Steller sea 

 lion under the Endangered Species Act, and establish 

 a Steller Sea Lion Recovery Team to expedite the 

 preparation of a recovery or conservation plan. 



On 5 April 1990, the National Marine Fisheries 

 Service published a Federal Register notice: (1) 

 listing the Steller sea lion as threatened under the 

 Endangered Species Act on an emergency basis; 

 (2) announcing the establishment of the Steller Sea 

 Lion Recovery Team; (3) repealing existing regula- 

 tions that allowed fishermen to shoot at or near sea 

 lions to prevent sea lion interactions with their fishing 

 gear; (4) reducing by half (from 1,350 to 675) the 

 number of Steller sea lions allowed to be taken 

 incidental to commercial fishing operations in the 

 region west of 141 ° west longitude (although the total 

 allowable take remained at 1,350, as an additional 675 

 were allowed to be taken east of 141 ° west longitude); 

 and (5) establishing no-entry buffer zones around the 

 principal Steller sea lion rookeries in parts of Alaska. 

 The emergency rules were effective through 3 De- 

 cember 1990. 



By letter of 18 May 1990, the Commission advised 

 the Service that: (1) the conservation measures con- 

 tained in the 5 April 1990 emergency rule could be 

 insufficient to reverse the observed population decline; 

 (2) the Conmiission continued to believe that the 

 species should be listed as endangered rather than 

 threatened; (3) with the exception of prohibiting the 

 discharge of firearms at or near Steller sea lions, all 

 measures contained in the emergency rule were 

 limited to Steller sea lions in Alaska and the Service 

 should consider adopting additional measures, includ- 

 ing designating critical habitat for Steller sea lions in 

 Washington, Oregon, and California as well as 

 Alaska; and (4) a critical habitat designation for 



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