BIOMARKER SENSITIVITY FOR POLYNUCLEAR AROMATIC HYDROCARBON CONTAMINATION IN 2 MARINE FISH SPECIES COLLECTED IN GALVESTON BAY, TEXAS

The Galveston Bay estuary exhibited a contamination gradient for polyn uclear aromatic hydrocarbons (PAHs) and halogenated aromatic hydrocarb ons, and the comparative sensitivity of various biomarkers in fish fro m different bay locations were determined. Two fish species, hardhead catfish (Arius felis) and Atlantic croaker (Micropogon undulatus), wer e collected from four stations where sediment total PAHs ranged from 6 8 to >1,000 ng/g. The induction of cytochrome P4501A-(CYP1A-) dependen t hepatic ethoxyresorufin-O-deethylase (EROD) activity, CYP1A mRNA lev els, or CYP1A immunoreactive protein in hardhead catfish was highly va riable in the field-collected fish and in fish dosed with up to 15 mg/ kg benzo[a]pyrene (BaP), In contrast, significant differences were see n in biliary concentrations of naphthalene, phenanthrene, and BaP meta bolites in hardhead catfish from polluted versus less polluted areas. In croakers taken from the same four Galveston Bay locations, EROD and glutathione S-transferase activities, immunoreactive CYP1A protein, b iliary PAH metabolites, and PAH-DNA adducts were higher at the contami nated stations compared with less polluted locations. These studies su ggest that the croaker is a good species for monitoring contaminants t hat induce CYP1A-mediated responses. Biliary PAH metabolites and PAH-D NA adducts were also sensitive indicators of exposure to PAH contamina tion in both species of fish.