Commercial Shrimp Production in the Northern Gulf of Mexico: Effects of Shrimp Habitat on Commercial Shrimp Fishery Catch

Abstract

The Gulf of Mexico penaeid shrimp fishery is perennially one of the most productive fisheries in the southeast United States in terms of landings and value. Since 2007, a mandatory fishery observer program has been collecting data to characterize the catch and bycatch of the fishery. Factors affecting production of the fishery have been the subject of research for several decades. Linkages between the production of the shrimp fishery and environmental factors are of increased interest as stock assessment methods attempt to utilize environmental data as they become available. It is generally thought that juvenile growth and survival are the most important factors determining yield, as natural mortality of shrimp is very high. To substantiate this hypothesis, a generalized linear model is used to relate juvenile shrimp habitat factors and shrimp fishery production. The novelty of the model stems from its use of fishery dependent observer data to provide insight into coastal nutrient loading and sub-adult shrimp habitat in regard to commercial catch rates (CPUE). Distance weighted variables derived from juvenile shrimp habitat representing nutrient loads and proportional shrimp habitat were calculated and used to represent the influence of these habitat variables on commercial shrimp catch rates. The effects of environmental variables on shrimp CPUE generally agree with effects concluded in previous studies. Evidence is presented in support of the theory that high nutrient loads delivered to coastal areas can increase secondary production. Shrimp CPUE predictions are evaluated in simulated scenarios representing environmental regime shifts.