Muscle chemical content and hepatic biotransformation in bream (Abramis brama) and asp (Aspius aspius) in a PCB-contaminated lake

During the period of 1956–1983, an approximated amount of 900 liters of polychlorinated biphenyls (PCBs) was discharged into a small freshwater lake in southern Finland. Biomonitoring study of the lake in 1998 revealed clearly detectable muscle PCB concentrations in the two feral fish species studied, bream (Abramis brama) and asp (Aspius aspius), suggesting persistent PCB contamination in the lake. The muscle PCB contents in bream and asp were 18 and 59 times higher than the corresponding values measured in reference locations. The hepatic monooxygenase EROD activities were significantly induced in fish caught from the lake, underlining the biomarker value of EROD measurements in monitoring long-term chemical exposure in field studies. The conjugation GST activities showed mostly seasonal differences and did not indicate the chemical stress of fish.