Using oysters from Galveston Bay as indicators, polynuclear aromatic hydrocarbons and pesticide body burden are studied. The eggs and sperm of the oysters contained more polynuclear aromatic hydrocarbons than the other tissues. Eggs contained large amounts of chlorinated compounds such as DDD and chlordane. Eggs and sperm contained higher concentrations of PCBs than the other tissues. In one spawn, oysters can lose half of their total body burden.