Significance of genotoxicity and toxicity evaluation of freshwater bodies

Abstract

Fish communities are excellent indicators of biological and ecological integrity due to their continuous exposure to water conditions. Freshwater biodiversity constitute a valu able natural resource but extensive pollution of freshwater can result in biodiversity de cline. For that reason it is important to employ bioassays for purpose of detecting these conditions. In this work we monitored chub and bream species in 2 reservoirs, Uvac and Garasi, and 4 rivers: Dunav, Sava, Pestan and Beljanica. For assessment of metal and metalloid in fish tissues (liver, gills, gonads and muscle) we have used ICP-OES. The comet assay or single cell gel electrophoresis (SCGE) was selected as an in vivo geno toxicity assay, for measuring DNA damage in blood, liver and gills. Histopathological alterations were monitored in liver and gills.The high quality of Uvac water was con firmed by low values of DNA damage in all tissues compared to other sites. An analysis metals in tissues showed a high degree of their differentiation, as well as significant dif ferences in the distribution of tissue elements between the sites tested. The highest con centrations of most of the analyzed metals were found in gills, liver and gonads, and the lowest in muscles at all sites. In chub, blood showed the lowest DNA damage compared to liver and gills, while in all breams DNA damage was the highest in blood cells, follow ing gills and liver. Histopathological analysis performed on bream specimens on the Sava and Danube River revealed a higher degree of alterations in liver compared to the gills.