Biochemical Indicators of Contaminant Exposure in Flatfish from Puget Sound, WA

Flatfish from Puget Sound, WA are shown to develop liver diseases which are correlated with aromatic hydrocarbon (AH) contamination of sediment. However, due to the efficient metabolism of AHs by these fish, AHs cannot be readily monitored in biological samples. Nonetheless, some biochemical measurements are shown to be useful indicators of exposure of fish to AHs. One such technique, currently in use, is the measurement of fluorescent aromatic compounds in the bile of fish sampled in the field. Another is the measurement of hepatic activities of aryl hydrocarbon hydroxylase (AHH), an enzyme which is readily induced in animals exposed to a variety of contaminants. However, each of these methods, used singly, can have some deficiencies for routine environmental monitoring. This paper reports data from field and laboratory studies where both of these techniques were used to assess the exposure of English sole to contaminants. The advantages of employing both of these methods in a monitoring program are described, and ways of enhancing the usefulness of these techniques are suggested.