Organic Pollutant Contamination of the River Tichá Orlice as Assessed by Biochemical Markers

Abstract

This study used biochemical markers to assess contamination at two contaminated sites (Králíky and Lichkov) and one control site (Červená Voda) on the River Tichá Orlice, a left-side tributary of the River Elbe. The brown trout (Salmo trutta fario) was selected as an indicator species. Enzymes of the first stage of xenobiotic conversion, namely cytochrome P450 (CYP 450) and ethoxyresorufin-O-deethylase (EROD) in the liver were selected as biochemical markers. Blood plasma vitellogenin concentrations were used to evaluate xenoestrogenic effects of contamination. Results were compared with the most important inductors of these markers, i.e. with organic pollutants (PCB, HCH, HCB, OCS and DDT and their metabolites in fish muscle and with PAH concentrations in bottom sediments). The highest contamination with organic pollutants was at Králíky, and this was reflected in increased cytochrome P450, EROD activity and vitellogenin concentrations. Significant differences were demonstrated in EROD activity and vitellogenin concentrations between Králíky and Červená Voda (P < 0.001). At the most contaminated site (Králíky), a significant negative correlation (rs = -0.964) between EROD activity and vitellogenin concentrations was demonstrated. This relationship was discussed from the point of view of a possible induction or inhibition of the assessed biomarkers at persistently highly contaminated sites.