Hepatic EROD activity in spot, Leiostomus xanthurus, exposed to creosote-contaminated sediments

Hepatic microsomal ethoxyresorufin O-deethylase (EROD) activity was measured in spot, Leiostomus xanthurus, exposed in a laboratory flowthrough system to sediments contaminated with coal-tar creosote for 14 days. Mean total resolvable polycyclic aromatic hydrocarbon (PAH) concentrations tested were 16, 35, 76, 150, and 320 μg/liter. Fish at all test concentrations refused food; control fish fed normally. Severe fin erosion, epidermal lesions, and mortality were observed in fish exposed to 76, 150, and 320 μg/liter. EROD activity was dependent on creosote concentration and time of exposure. Median EROD activity in control fish was 62 pmol/min/mg protein ( N = 28). EROD activity in fish exposed to 35, 76, 150, and 320 μg/liter increased during the first 2 days of exposure and then declined. Maximal induction was almost 30-fold at 150 μg/liter. By day 7, EROD activity was not significantly different than that on day 0.