Predicting long-term effects of freshwater inflow on macrobenthos in the Lavaca-Colorado and Guadalupe estuaries : year 2 : final report

Two estuaries have been studied to determine the effect of year-to-year variation of freshwater inflow on macrobenthic infauna. The estuaries have similar inflow characteristics, but the Lavaca-Colorado has direct exchange of coastal marine water with the Gulf of Mexico and the Guadalupe does not. Studies in the Lavaca-Colorado began in 1984, and studies in the Guadalupe began in 1987. There are changes in community structure and function from year-to-year, which can be linked to the long-term cycle of wet and dry years along the Texas coast. There appears to be a long-term cycle of high-inflow stimulated recruitment, followed by nutrient depletion and recruitment of marine species during low-inflow periods, followed by declines in productivity until the next wet year. These cycles appear to have a period of 2-3 years, but it will take at least 3 more years of data to test this hypothesis