Fish biochemical markers as a tool for pollution assessment on the Svitava and Svratka rivers, Czech Republic.

OBJECTIVES: The study was designed to assess the pollution of the Svitava and Svratka rivers in and around the industrial city of Brno (Czech Republic) by persistent organic pollutants using selected biochemical markers in chub.

DESIGN: Levels of selected biochemical markers were measured in liver and plasma samples of chub. The concentrations of persistent organic pollutants (POPs) were determined in bottom sediment, semi-permeable membrane devices (SPMDs) and muscle samples, and consequently used for correlation with biochemical markers.

RESULTS: Significant alterations (p < 0.05) in some biochemical markers were observed and associated with combined exposure to pollutants. The highest levels of pollutants were found at sites situated downstream from Brno. The most widespread changes were identified in the function of phase I detoxifying enzymes. Significant positive correlations were observed in cytochrome P450 content and DDT concentration in the semi-permeable membrane device (p = 0.019, rs = 0.886), and between ethoxyresorufin-O-deethylase activity and content of DDT (p = 0.041, rs = 0.352) and polychlorinated biphenyls (p = 0.034, rs = 0.365) in muscle tissues of indicator fish.

CONCLUSION: The results presented in our study indicate the highest contamination of sites situated downstream from Brno, where the intensive industrial and agricultural activities as well as domestic waste and sewage most probably comprise the main impact sources of the enhanced level of pollutants and some biochemical markers in fish.