MFO induction potential of fish species native to the Swan–Canning Estuary, Western Australia

The use of mixed function oxygenase (MFO) enzymes as a potential biomarker of pollution in the Swan‐Canning Estuary was investigated in four indigenous fish species, Perth herring ( Nematalosa vlaminghi ), sea mullet ( Mugil cephalus ), yellowtail trumpeter ( Amniataba caudavittata ), and black bream ( Acanthopagrus butcheri ). Each experimental fish was intraperitoneally injected with 10 μg/kg of 3,3′,4,4′,5‐pentachlorobiphenyl per kilogram of fish using corn oil as a carrier. Controls were injected with 1 mL corn oil per kilo. Induction of the hepatic ethoxyresorufin‐ O ‐deethylase (EROD) activity was measured 10 days post injection. Perth herring did not survive the experimental period due to the poor ability of this fish to endure captivity and handling. Yellowtail trumpeter demonstrated a low EROD induction response (2‐fold relative to controls), while sea mullet displayed a moderate EROD induction potential (3.5‐fold relative to controls). Because of their lower EROD induction potential, yellowtail trumpeter and sea mullet were not considered the most suitable bioindicator species for Western Australian estuarine waters. Black bream has desirable population traits and had a relatively high MFO induction potential response (9‐fold relative to controls). From the results it was concluded that, when using EROD induction as a biomarker, black bream is a suitable fish to use as a bioindicator species for investigations into the health of the Swan‐Canning Estuary. © 2002 by Wiley Periodicals, Inc. Environ Toxicol 17: 87–92, 2002