Bioaccumulation of Metals and Metallothionein Levels in Some Fish Species Living in Murat River

The aim of this study was to determine the levels of Cd, Co, Cr, Fe, Mn, Mn, Pb, Ni, Zn and hepatic metallothionein (MT) in muscle, liver, kidney and gills of Capoeta trutta and Capoeta umbla caught from the Murat River. The length and weight of the fish were measured. The physical and chemical properties of the river water were measured and compared with the tolerable limits of Turkish Standards Institute (TSE). The tissues to be analysed for heavy metals were prepared for the analyses using the wet incineration method in a closed system. The heavy metal content of the samples was measured by inductively coupled plasma optical emission spectroscopy (ICP-OES). Differences in heavy metal accumulation of Capoeta trutta and Capoeta umbla in different tissues and different metal species were determined. The levels of Cr, Mn, Ni and Fe in the muscle tissues of Capoeta trutta were higher than the limits recommended for fish by the Turkish Food Codex (TGK), the Food and Agriculture Organization (FAO) and the World Health Organisation (WHO). Muscle Cr, Mn, Ni and Fe levels of Capoeta umbla were higher than the tolerable levels recommended by FAO and WHO. Heavy metals cannot be metabolised in tissues. They tend to accumulate. It has been observed that this accumulation varies in muscle, liver, kidney and gills according to organ structure, metabolic activity and defence mechanisms against toxic substances. MT, an indicator of tissue metal accumulation, was found to differ between Capoeta trutta and Capoeta umbla liver tissues.