The water quality of rivers located in areas close to major cities is deteriorating significantly due to increased pollution. The Karasu River, which passes through Erzurum city Turkey, is getting polluted day by day due to domestic and industrial wastewater. In the study, various assessments were made in three different fish species to determine the impact of possible contamination here. Capoeta capoeta, Alburnus mossulensis and Squalius cephalus were caught from four stations of the river. Micronucleus test was applied to find out genotoxic alterations, and plasma total oxidant status (TOS) and total antioxidant status (TAS) were measured to determine oxidative effects. |