The purpose of the work is to measure the concentrations of total and pathogenic V. vulnificus and V. parahaemolyticus in water, bottom sediment and oysters in Breton Sound and Barataria Bay, to measure environmental parameters, in particular salinity, temperature, turbidity and chlorophyll and to compare the concentrations of total and V. vulnificus and V. parah aemolyticus before and after the oil spill.