Temperature and Salinity Effects on the Growth and Survival of Juvenile Penaeid Shrimps: Implications for the Influence of River Diversions on Production (2006-2008)

PIs: Lawrence P. Rozas, Thomas J. Minello, and Doran Mason

Water-control structures are currently being used, and additional structures are being planned, on the northern Gulf of Mexico to divert river water into nearby estuaries for wetland restoration. These freshwater flows directly alter the temperature and salinity of estuarine waters, which can influence the distribution and productivity of penaeid shrimps and other fishery species. Currently, too little is known about the environmental requirements of penaeid shrimps to design and operate diversions to both restore wetlands and minimize impacts to penaeid shrimps. We are using a series of experiments to examine relationships between the growth and survival of juvenile white shrimp and brown shrimp and two key environmental variables (water temperature and salinity) affected by freshwater inflows. We are examining these relationships using continuously recorded environmental data and growth and survival data from shrimp caged along a salinity gradient in the Barataria Bay estuary, Louisiana. In addition, we will examine the relationship between shrimp growth rates in the field and the availability of potential prey. Experiments also are being conducted in the laboratory to examine salinity selection by shrimp. The results from these experiments will be incorporated into simulation models to predict effects of temperature and salinity on shrimp growth and survival. These models can be linked to a hydrology-hydrodynamic model and used in conjunction with different river diversion scenarios to assist managers in minimizing the impacts of freshwater releases on shrimp production when restoring coastal systems. Our project will support Ecosystem Management of the northern Gulf of Mexico by enhancing our understanding of the environmental requirements for juveniles of brown shrimp and white shrimp and the link between the estuarine environment and shrimp production. Our study also will advance a modeling approach that may provide a useful tool for evaluating river diversions used for wetland habitat restoration.  This research project is being supported by a grant from the Northern Gulf Institute.