Concentrations of metals in tissues of fish from the Vestonice reservoir

The aim of the present work was to compare the distribution of selected metals in tissues of several fish species caught in the Vestonice reservoir, Czech Republic. The hygienic quality of fish meat was assessed with respect to the mercury concentration. A total of 35 fish of the following species were caught: carp (Cyprinus carpio), bream (Abramis brama), asp (Aspius aspius), pike perch (Sander lucioperca) and pike (Esox lucius). Samples of muscle, liver (hepatopancreas), kidney, gonads and gills were analyzed. Hg, Pb, Cd, Cu, Zn and Cr concentrations in fish tissues were determined by the AAS. The results showed that different metals differ in their affinity to different fish tissues (e.g. Cu - liver, Cd - kidney). Hg concentrations along the food chain increase, i.e. higher Hg concentrations are found in predatory fish. Contrary to Hg, Cd and Pb concentrations do not show any increases along the fish part of food chain in surface water ecosystems. In predatory fish, lower concentrations of these metals were found than in non-predatory fish species. Differences in concentrations between ovaria and testes were found only in Cu and Zn. To evaluate possible health risks of Hg concentrations for consumers, the risk index was calculated and maximum admissible amounts of muscle meat for consumption were determined. The results confirmed good hygienic quality of market-ready fish from the Vestonice reservoir.