Sublethal detoxification responses to contaminant exposure associated with offshore production platforms

Several biomarkers of aromatic hydrocarbon exposure were used to evaluate contamination associated with petroleum and gas development and production in the Gulf of Mexico. Several species of fish and invertebrates were sampled at stations <100 m (near) and >3000 m (far) from the center of three platforms. No significant near/far station differences were observed in aryl hydrocarbon hydroxylase (AHH) activity for any invertebrate species. The only significant induction of ethoxyresorufin O-deethylase (EROD) activity in H4IIE cell bioassays was observed in cells dosed with extracts of brown shrimp (Penaeus aztecus) sampled at MAI-686 near station. However, a sediment contaminant gradient was not detected at this platform. No significant near/far station differences in EROD and AHH activities, CYP1A mRNA levels, and biliary polynuclear aromatic hydrocarbon (PAH) metabolite concentrations were detected in 16 species of fish. However, species-dependent differences in EROD activity and biliary PAH metabolite levels were detected. Additionally, a radiolabeled nuclear aryl hydrocarbon receptor complex was characterized for two fish species.