ACCUMULATION OF HEAVY METALS (Cu, Zn, Ni, Cr, Pb, Cd) IN TISSUES OF PERCH (Perca fluviatilis L.) AND ROACH Rutilus rutilus (L.) UNDER EXPERIMENTAL CONDITIONS

The paper analyses the effects of heavy metals on freshwater fishes, From the point of view of Pollution caused by heavy metals, the condition of ecosystems in Lithuania is yet less affected by heavy metals compared to that the world over. Fishes accumulate heavy metals selectively. Fishes mostly accumulate Pb. Cr. Cd, Our experiments showed that MPC (Maximum Permitted Concentration) (0.2 mg/kg) of lead was exceeded 1.6 time in the muscles of perch, and 1.4 time - in the muscles of roach. The MPC (0.05 mg/kg) of cadmium was exceeded 1.2 time in the muscles of perch and roach. It was determined that perch accumulate heavy metals more intensively than roach. Heavy metals accumulate in fishes: liver > muscle> gills. As heavy metals are considered to be one of the most harmful water pollutants, there is a great need for a constant ecological monitoring and reduction of their amounts released into the environment. According to long-term research data. the MPC in fishes is exceeded only slightly. This confirms a good condition of aquatic ecosystems in Lithuania.