Evaluation of the population dynamics and yield characteristics of Alaska plaice, Pleuronectes quadrituberculatus, in the eastern Bering Sea

Alaska plaice, Pleuronectes quadrituberculatus, are one of the major shallo w water flatfish species in the eastern Bering Sea ecosystem. It is most hi ghly concentrated in the shallow continental shelf waters of the eastern Be ring Sea. The stock has been lightly exploited and annual commercial catche s have ranged from less than 1000 metric ton (t) in 1963 to 62 000 t in 198 8. Current stock assessments have characterized the resource as being in a high and stable condition. However, these assessments have relied mainly up on the time-series of demersal trawl surveys conducted annually in the east ern Bering Sea. We extend the assessment of this species through the use of age-structured models such as stock synthesis analysis and biomass-based m odels using all available catch and survey information. These age-structure d models indicate that the stock biomass has steadily declined from a peak level in the early 1980s due to a lack of recruitment, Optimum yield and ag e at first capture are examined and important management parameters are est imated (MSY, B-MSY, F-MSY) Finally, appropriate future harvest strategies a re investigated under a range of possible fishing intensity levels. (C) 199 9 Elsevier Science B.V. All rights reserved.