Residues of Pollutants in Siluriformes from Various Locations of the Czech Republic

Abstract

S v 0 bod 0 v a Z., v. Pia c k a, B. V Y k u s 0 v a, 1. M Ii c h 0 v a, M. H e j t man e k, M. H r b k 0 v a, J. Bas t I: Residues of Pollutants in Siluriformesfrom Various Localities of the Czech Republic. Acta vet. Bmo 1995,64: 195-208. Tissues (muscle, kidney, liver, gonads) were investigated for residues of pollutants in wels (Silu­ rus glanis) from 6 large ponds (Bezdrev, Spolsky, Kaclehy, Vrko<:, NovoveskY, Bezruc), from Labe river and from the OrUk reservoir and in brown bullhead (lctalurus nebulosus) from the river Labe. Thirty and 10 individuals of wels were investigated from ponds and the Orlik reservoir, respecti­ vely, and 2 individuals from the river Labe. Thirty five individuals of bullhead were investigated from various localities of the Labe. Among pollutants, metals (Hg, Pb, Cd, Cu, Zn, Cr, AI), PCBs as amount of technical mixtures used in .the Czech Republic (Delor 103 and Delor 106) and as 7 indicator congeners (K28, K52, KIOI, K118, K153, K138, KI80), DDT and its metabolities, HCB, HCH isomers, triazines (atrazine, simazine, prometryne, desmetryne, terbutryne) were assessed. The values of individual pollutants found in tissues of wels from ponds were very low and corres­ ponded to hygienic limits in all cases. On the other hand, much higher values of pollutant residu­ es (Hg and PCB) were found in wels from the OrUk reservoir, and they exceeded the hygienic limit in some cases (PCB). Values of pollutant residues found in bullhead fished from various localiti­ es of the Labe were also increased. Above all, PCB and mercury values exceeded valid hygienic limit of the Czech Republic in some cases. Wels and brown bullhead proved to be important indicators of loading of various localities of surface waters with investigated pollutants. Wels as a predator and brown bullhead as an omnivo­ rous and benthophagous fish are important indicators of loading of surface waters with mercury. The muscles of wels are besides those of eel (Anguilla anguilla) one of the most important indica­ tors for the evaluation of surface waters loading with polychlorinated biphenyls. Silurus glanis, Ictalurus nebulosus, pond, Labe river, OrUk reservoir, mercury, metals, PCBs, indicator congeners, DDT, BCB, BCB, triazines