Application of Catch-Survey Models to the Northern Shrimp Fishery in the Gulf of Maine

Abstract

Abstract The fishery for northern shrimp Pandalus borealis in the Gulf of Maine was modeled to assess the impacts of recent increases in fishing effort and landings. A Collie–Sissenwine analysis of landings and research vessel survey data from 1985 to 1997 indicates that instantaneous annual fishing mortality rate (F) substantially increased in the last 2 years and reduced the stock to a low level of abundance. A nonequilibrium surplus production model (ASPIC) of 1968–1997 landings and survey indices provides similar results. Estimates of F ranged from 0.1 to 0.5 for 1985–1995 and increased to 0.7 in 1996 and to 0.9 in 1997, while abundance of northern shrimp decreased in 1998 to the lowest level since the early 1980s. Fishing mortality rates greater than 0.6 were associated with a stock collapse in the 1970s, suggesting that stock biomass decreased when spawning potential was reduced to less than 10% of maximum. In the absence of reliable stock–recruitment information, F20% (0.63) may be a precautionary ...