Did the Texas Closure Increase Brown Shrimp Catches off Texas?

Abstract

AbstractThe annual catch of brown shrimp Farfantepenaeus aztecus off Texas is forecasted by the National Marine Fisheries Service using a model that relates spring (April–June) juvenile abundance in Galveston Bay to subsequent offshore catch (July to the following June). The model is not well documented, nor has it been used rigorously to examine the success of management actions in enhancing the fishery. State and federal agencies use an areal closure of Gulf of Mexico waters deeper than 4 fathoms from late May to early July to increase shrimp abundance, catch, and value by delaying the harvest of emigrating juvenile shrimp. This study reports a preclosure (1960–1980) regression that explained over 70% of the variation in offshore Texas catches as a function of the juvenile abundance index from Galveston Bay. Positive effects of the closure—in terms of increasing the catch for a given level of juvenile abundance in 1981–2007—were not found in this study. However, the utility of the relationship between the juvenile abundance index and catch as a forecasting tool continued through 2007, but with less precision than in the preclosure regression.