MARINE MAMMAL COMMISSION — Annual Report for 1991 



By the late 1980s, it had become even more 

 apparent that the declines in Steller sea lion, fur seal, 

 harbor seal, and seabird populations, and the signifi- 

 cant annual variation in the biomass of walleye 

 pollock and other fish and crustacean species in the 

 Bering Sea and Gulf of Alaska needed to be analyzed 

 as interconnected parts of the ecosystem, rather than 

 as separate conservation and management units. In 

 the summer of 1990, the Marine Mammal Commis- 

 sion consulted with a broad range of agencies and 

 individuals with expertise and responsibilities regard- 

 ing the Bering Sea and Gulf of Alaska. From these 

 consultations emerged a consensus that available 

 information should be compiled and evaluated as soon 

 as possible to identify critical uncertainties and re- 

 search needs for key components of these ecosystems 

 and that this could best be accomplished by a work- 

 shop. 



The Commission subsequendy consulted scientists 

 from the National Marine Fisheries Service, the Fish 

 and Wildlife Service, the Alaska Department of Fish 

 and Game, the University of Alaska, the University of 

 Washington, and other institutions to develop a 

 workshop agenda and identify participants. As marine 

 research programs being initiated in the seas surround- 

 ing Antarctica (see Chapter IV) are intended, in part, 

 to avoid the types of management problems presently 

 being faced in the Bering Sea and Gulf of Alaska, the 

 Commission concluded that it might be useful to 

 compare research and management approaches in the 

 two areas. Thus, the scope of the workshop was 

 expanded to include consideration of how experience 

 in the Southern Ocean might be used to improve 

 research planning and management in both areas. The 

 objectives of the workshop were to: (1) identify 

 critical uncertainties concerning the causes of and 

 possible relationships among the observed population 

 declines in the Bering Sea and Gulf of Alaska; 

 (2) identify the research that would be required to 

 resolve the uncertainties; and (3) determine how to 

 improve research planning and resource management 

 in both areas. 



The workshop, funded by the Commission and the 

 National Marine Fisheries Service, was held in 

 Seattle, Washington, on 12-13 December 1990. The 

 participants identified the types of research that would 

 be required to answer key questions about the struc- 



ture and relationships among key components of the 

 Bering Sea and Gulf of Alaska ecosystems and the 

 causes of the population declines. With respect to 

 marine mammals, the participants concluded that the 

 most critical uncertainties were: (1) the location and 

 availability of key prey species in areas where Steller 

 sea lions and harbor seals feed during the pupping and 

 breeding seasons; (2) the winter distribution, move- 

 ments, and critical feeding areas of different age and 

 sex classes of Steller sea lions and harbor seals; and 

 (3) the diet and principal feeding areas of North 

 Pacific fur seals in their first two years of life. They 

 also cited many areas where avaUable data are insuffi- 

 cient to support ecosystem-based management. 



The workshop report, published in July 1991, 

 recommended improved research and monitoring 

 programs for many species for which there is insuffi- 

 cient information to draw conclusions about the 

 observed declines. The recommendations included: 

 (1) continuing ongoing programs to assess and moni- 

 tor Steller sea lions and North Pacific fur seals in the 

 Bering Sea and Gulf of Alaska; (2) expanding efforts 

 to identify and monitor declining harbor seal popula- 

 tions; (3) compiling and comparing fishery survey 

 data, and data on fishery development, fish catches, 

 and incidental take of marine mammals in the Bering 

 Sea and Gulf of Alaska with available data on the 

 Steller sea lion, fur seal, and harbor seal declines; (4) 

 continuing and expanding efforts to use satellite-linked 

 radio tags to determine the at-sea movements and 

 important feeding areas of Steller sea lions in order to 

 obtain information by season, age, and sex; (5) 

 expanding the satellite-linked tracking program to 

 obtain information on the at-sea movements and 

 important feeding areas of harbor seals in regions 

 where declines have occurred; (6) if possible, using 

 similar techniques to determine the movement patterns 

 and possible critical habitats of fur seals during their 

 first two years of life; and (7) surveying representa- 

 tive Steller sea lion, fiir seal, and harbor seal feeding 

 areas to establish baselines and monitor the availabili- 

 ty and nutritional quality of food fish present in the 

 areas. 



The workshop report was forwarded to the Fish 

 and Wildlife Service, the National Marine Fisheries 

 Service, and the National Science Foundation on 25 

 July 1991. At that time, the Commission made 



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