V. Atanasov, E. Valkova, G. Kostadinova, G. Petkov, N. Georgieva, Ts. Yablanski, G.Nikolov

Abstract. The concentrations of 8 elements (Fe, Mn, Cu, Cr, Ni, Zn, Pb and Cd) were determined in the water and liver by common carp (Cyprinus carpio L.) from 6 waterbodies in Stara Zagora region using atomic absorption spectrometry. Despite having a reputation for being heavily polluted, the investigated waters were not heavily burdened with examined metals. Our results suggest that fish liver were accumulating elements in the same manner such are increasing metal concentrations in waterbodies. Heavy metals concentrations were highest in the water and carp liver from Zagorka Lake and Ovcharitsa Dam, and especially of the Pb did exceed established quality standards for fish. Because the liver accumulates highest levels of heavy metals, it may to be use as an important biological indicator for ecological monitoring of the fish inhabiting waterbodies.