Management of the Gulf of Mexico shrimp stocks: Assessments and economics

The Southeast Fisheries Science Center currently uses VPA models to annually assess three major shrimp stocks (brown, white, and pink) in the Gulf of Mexico.  Current economic conditions in these shrimp fisheries have caused dramatic reductions in effort.  Yet, this reduced effort has not resulted in a decrease in overall yield.  Trends in commercial fisheries dependent landings, effort, CPUE, and the VPA models will be discussed.  As a first step to upgrade our assessments from the VPA we have migrated the pink shrimp assessment data into Stock Synthesis.  We tested the applicability of Stock Synthesis to the commercial pink shrimp data using a preliminary model setup of one random year of data.  In this test configuration, Stock Synthesis was able to fit both weight and age composition data.  Subsequent full time series runs in Stock Synthesis illustrated the model’s ability to fit the expected and observed values of CPUE, revealing the applicability of this model to these data.  In these full model runs, spawning biomass, numbers of recruits, and CPUE estimates were also generated.  Upon completion of the model calibration with fisheries dependent shrimp data we plan to incorporate fishery independent abundance surveys and environmental data into future models.