The fate of Galveston Bay oyster populations in the first 50 years of the 21st century under the Texas water plan

A coupled hydrodynamics/population dynamics model has been developed to assess the impact of reduced freshwater inflow into Galveston Bay in the first 50 years of the next century on oyster production in the bay. Simulations were run for the present-day hydrology and the 2024 and 2049 hydrologies predicted by the Texas Water Plan. The results of simulations of low, mean, and high freshwater inflow years show that Galveston Bay oyster populations decline in abundance by 50 to 90% depending upon the hydrology used. Oyster populations decline because of increased disease (Perkinsus marinus) intensity produced by the upestuary movement of the isohalines and because of reduced scope for growth and increased mortality associated with reduced salinities downestuary of the San Jacinto River produced by the freshwater diversion. The simulations indicate that a change in the route of freshwater inflow into Galveston Bay is even more detrimental to the bay's oyster populations that is a reduction of freshwater inflow into the bay