Analyses of Bivalves and Sediments for Organic Chemical and Trace Elements: Second Annual Report

The purpose of the Mussel Watch Program is to determine the long-term temporal and spatial trends of selected environmental contaminant concentrations in bays and estuaries. The key questions in this regard are: (1) What is the current condition of the nation's coastal zone?; and (2) Are these conditions getting better or worse? This report contains the first two years of data from a multi-year program. Only the first questions can be addressed in detail at this time. The following is an estimate of the current condition of the Gulf of Mexico coastal zone, based on Years I and II results of the NOAA Mussel Watch Program. Sediments and oysters were collected at 51 (153 stations) and 49 sites (147 stations), respectively. These samples were analyzed for contaminant concentrations (trace metals, polynuclear aromatic hydrocarbons (PAH), pesticides, and PCB's), disease incidence and other parameters that aid in the interpretation of contaminant distributions (coprostanol, grain size, oyster size, carbon content, etc.). This report provides the most extensive and highest quality data base for contaminant concentrations yet produced for Gulf of Mexico coastal areas. A complete and comprehensive interpretation of these data will require continued analyses over several years, and only a summary of preliminary findings is reported here.