MARINE MAMMAL COMMISSION — Annual Report for 1995 



not employ the measures required to minimize inci- 

 dental mortality. Further, many of the seabird and 

 other non-target species being caught and killed in 

 fisheries in the convention area also are caught and 

 killed in fisheries outside the convention area. Thus, 

 while there is reason to believe that measures institut- 

 ed by the Antarctic Living Resources Commission 

 have reduced seabird mortality in the convention area, 

 data are insufficient to accurately estimate the level of 

 unreported take or the impacts of the take on the 

 affected stock. Further, it is not clear whether there 

 is significant under-reporting of incidental catches of 

 marine mammals, seabirds, and other non-target 

 species in krill or other trawl fisheries. 



Ecosystem Monitoring and Management — The 



Convention for the Conservation of Antarctic Marine 

 Living Resources is unique in that it specifies that 

 fisheries must be managed to prevent adverse impacts 

 on other species dependent on or associated with 

 harvested species, as well as to prevent over-exploita- 

 tion and depletion of harvested species. As noted in 

 previous Marine Mammal Commission annual reports, 

 the Scientific Committee for the Conservation of 

 Antarctic Marine Living Resources established a 

 working group in 1984 to formulate and coordinate 

 implementation of a multinational program to assess 

 and monitor the status of key components of the 

 Antarctic marine ecosystem. The working group 

 developed and recommended adoption of a long-term 

 monitoring program with three components: (1) 

 monitoring of representative land-breeding krill 

 predators (e.g., Antarctic fur seals and Adelie and 

 chinstrap penguins) at a network of sites throughout 

 the Antarctic, (2) comprehensive studies of krill, krill 

 predators, and environmental variables in three 

 integrated study areas (Prydz Bay, the Bransfield 

 Strait, and the area around South Georgia Island), and 

 (3) directed studies of crabeater seals, one of the 

 principal consumers of Antarctic krill, in one or more 

 pack-ice areas. 



Because of the central role of krill in the Antarctic 

 marine ecosystem, there necessarily has been some 

 overlap in the responsibilities of this working group 

 and of the working group constituted to assess and 

 provide advice on krill stocks. In 1993 and 1994 

 portions of the intersessional meetings of these two 

 working groups were held concurrently to consider 



issues of joint interest. In 1995 the two groups were 

 combined to form the working group on ecosystem 

 monitoring and management. 



The new working group met for the first time in 

 August 1995. Prior to the meeting, the Department 

 of State, in consultation with the Marine Mammal 

 Commission, the National Marine Fisheries Service, 

 and the National Science Foundation, convened a 

 meeting of U.S. scientists with firsthand experience in 

 studying and modeling various components of the 

 Antarctic marine ecosystem to provide advice on a 

 range of matters to be considered by the new working 

 group. The advice of this ad hoc group of scientists 

 was used to help develop U.S. positions regarding 

 issues considered at the working group meeting and 

 the subsequent meetings of the Antarctic Living 

 Resources Commission and Scientific Committee. 



At its meeting in August 1995 the working group 

 on ecosystem monitoring and management began 

 formulation of a strategic model to assist in the 

 assessment of measures needed to maintain the integri- 

 ty of the Antarctic marine ecosystem and to evaluate 

 the effectiveness of management actions taken. The 

 model incorporates biological, environmental, and 

 fishery variables and the links between them. Both 

 the Scientific Committee and the Commission en- 

 dorsed formulation of a strategic model as proposed 

 by the working group. They also noted the overlap 

 between the location of much krill harvesting and the 

 foraging areas of krill-dependent predators and the 

 need to (a) ensure that krill catches are not concentrat- 

 ed in time and space to an extent that local popula- 

 tions of dependent species may be affected adversely 

 and (b) take into account relevant biological and 

 environmental variables, and uncertainties concerning 

 those variables, when determining precautionary catch 

 limits and subdividing limits set for broad areas. 



Continued formulation of a strategic ecosystem 

 model and other ecosystem-related matters will be 

 considered further at the next meeting of the working 

 group to be held in Bergen, Norway, 12-22 August 

 1996. The Department of State, in consultation with 

 the Commission, the National Marine Fisheries 

 Service, and the National Science Foundation, plans 

 to convene a meeting of knowledgeable U.S. scientists 

 early in 1996 to help identify issues that should be 



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