Chapter III — Species of Special Concern 



Steller sea lion habitats, provisions to minimize 

 commercial fishing impacts on sea lion prey resourc- 

 es, and other management issues. 



As a related matter, the Service's notice also 

 described certain conclusions and recommendations 

 made by the Steller sea lion recovery team. To assure 

 that the Service's research program provides the best 

 possible basis for making management decisions, the 

 team had recommended constituting a series of 

 separate review panels with appropriate team members 

 and outside experts to evaluate Service plans for work 

 in the areas of satellite telemetry, physiology and 

 health, and food habits. It also noted that the team 

 had concluded that a change in food availability is the 

 leading hypothesis for explaining the cause of the 

 western stock's decline. 



In reviewing the Endangered Species Act listing 

 proposal late in 1995, the Commission considered the 

 above points with a view towards including comments 

 on management related needs. Based on its review, 

 the Commission concurred with the recovery team 

 concerning the likelihood that prey availability was an 

 important factor in the decline of Steller sea lions. 

 Noting the importance of better information on sea 

 lion food preferences and foraging ecology to evaluate 

 this hypothesis and related management actions, the 

 Commission expected to recommend to the Service 

 that (1) the research program reviews suggested by 

 the recovery team be prioritized to first examine plans 

 for satellite-telemetry studies and foraging ecology 

 research, and (2) the Service set aside funds as the 

 recovery team may need to conduct reviews and other 

 business in a timely manner. 



The Commission also observed that it seemed 

 possible, if not probable, that commercial fishing was 

 among the factors affecting sea lion prey. Unfortu- 

 nately, despite considerable research efforts, informa- 

 tion remains insufficient to determine precisely which 

 fisheries may have the greatest effect on sea lion prey 

 resources, the fishing areas of greatest concern, or the 

 extent to which fisheries may affect sea lion prey 

 availability. 



Given these gaps and recognizing the urgent need 

 to reverse the sea lion decline, the Commission 

 concluded that the most effective way to develop and 



evaluate appropriate fishery management measures 

 may be through an experimental approach whereby 

 different regulations or management measures are 

 applied to different haul-out sites, feeding areas, or 

 parts of the sea lion's range. The Commission also 

 recognized the need for a comprehensive review of 

 how commercial fisheries are being and should be 

 managed to mitigate potential impacts on sea lion 

 prey, similar to the review of research program 

 elements recommended by the recovery team. The 

 Commission therefore expected to recommend that the 

 Service, in consultation with the recovery team, 

 convene a panel of experts to evaluate and make 

 recommendations on the full range of fishery manage- 

 ment practices that may be useful for reversing the 

 decline of Steller sea lions. 



Steller Sea Lion Stock Assessments 



Amendments to the Marine Mammal Protection 

 Act in 1994 established a new regime to govern the 

 incidental taking of marine mammals in commercial 

 fisheries. Among other things, they required the 

 National Marine Fisheries Service to prepare stock 

 assessments for all marine mammal stocks in U.S. 

 waters. Each assessment is to estimate the size and 

 maximum productivity rate of the stock, calculate a 

 potential biological removal level (not including 

 natural mortality) that would allow the stock to 

 increase towards its optimum sustainable population 

 level, assess incidental-take levels in commercial 

 fisheries, and determine if a stock is a strategic stock 

 requiring special attention. 



The Service circulated draft stock assessments in 

 August 1994 that included assessments for two stocks 

 of Steller sea lions — a western U.S. stock and 

 eastern U.S. stock. Final stock assessments were 

 circulated in August 1995. 



Based on the 1994 sea lion population survey, the 

 final assessment for the western U.S. Steller sea lion 

 stock estimates the total stock size at 43,200 animals, 

 including 9,600 pups. As data were not available to 

 calculate the stock's maximum productivity rate, a 

 general default value for all pinnipeds of 12 percent 

 per year was considered the best estimate for this 

 population parameter. With these estimates and other 

 data, the Service calculated a potential biological 



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