METAL ACCUMULATION IN CRAYFISH, PROCAMBARUS-CLARKII, EXPOSED TO A PETROLEUM-CONTAMINATED BAYOU IN LOUISIANA

Red swamp crayfish (Procambarus clarkii) mere placed for a period of 7 days in Bayou Trepagnier, a Louisiana waterway which received petrole um-laden effluents from a manufacturing complex several decades ago. H owever, coolant water from the plant continued to be released into the bayou until 1995. Analyses of sediments at the exposure site revealed heavy contamination by lead, chromium, and copper, while concentratio ns of arsenic and cadmium were very low, Significant bioaccumulation o f lead was observed in the hepatopancreas and gills of 7-day-exposed c rayfish, whereas chromium accumulated the most in the gills and blood. Concentrations of copper in the crayfish did not change during the co urse of the study, suggesting that this essential metal constituent of the respiratory pigment is successfully regulated even when crayfish are exposed to relatively high levels of copper in the sediments, Ther e was no metal accumulation in the abdominal muscle of the crayfish, T hat damage to the hepatopancreas occurred during the exposure is sugge sted by histopathological studies which revealed swollen and vacuolate d R cells and an increase in the pH of the digestive juices, Blood glu cose levels, as well as ovarian and hepatopancreatic indices, were unc hanged, This study demonstrates that accumulation of nonessential meta ls in crayfish tissues in a wetland environment contaminated by mixed pollution (metals and hydrocarbons) reflects the concentrations of met als in the sediment. (C) 1997 Academic Press.