Gulf coast National Oceanic and Atmospheric Administration National Status and Trends mussel watch: The first four years

Oysters have been employed as bioindicator organisms to characterize the current status and long-term trends for trace elements and organic contaminants. Sampling sites (50-69), distributed throughout the Gulf of Mexico and away from known point sources of input, are sampled yearly to provide a geographical description of the chronic contaminant loading of the entire Gulf on a regional basis. The general trend is contaminant concentrations that show no significant changes during the four-year sampling period. However, certain sites have experienced significant changes in contaminant concentration.