Abstract
Historical records indicate that oyster reefs were once a significant feature of Gulf of Mexico estuaries. Alterations in freshwater inflow resulting from watershed development and water management practices have impacted salinity and water quality, and led to declines in oyster populations within southwest Florida estuaries including Hendry Creek, Estero Bay. This project examined the relationship between contaminants, seasonal f actors, and water quality on the responses of eastern oyster, Crassostrea virginica, in Hendry Creek within the Estero Bay watershed. Levels of heavy metals, pesticides, and PCBs in the water column and in the oyster tissues, along with water quality parameters were con-elated with condition index, disease prevalence of Perkinsus marinus, reproductive state of adult oysters, growth and survival of caged juvenile oysters, and oyster spat settlement. Results indicate that oyster metal concentrations varied between sampling locations and months, even though most metal concentrations were below national averages. Oyster condition index, spat recruitment, and the prevalence and infection intensity of Perkinsus marinus showed a seasonal trend, and all increased downstream. Oyster responses con-elated more with seasonality (salinity), rather than contaminant levels. These results will help establish water quality targets for restoration and provide an understanding of the cumulative impacts of land use management practices on oyster population in Estero Bay watershed.
