The gonadal health status of Cyprinidae fish species collected from the river impacted by anthropogenic activities

Many freshwater ecosystems are contaminated with heavy metals released by municipal wastewater, cultivation and factory wastewater. The aim of the study was to evaluate the negative impact of metal pollution on the fish reproductive system. It was performed using the gonadal histopathology, hepatosomatic index (HSI), and gonadosomatic index (GSI) of three fish species, Capoeta damascina, Squalius semae and Alburnus sellal inhabiting in Karasu River (Erzurum, Turkey) contaminated by various anthropogenic activities. The highest GSI values were determined for each sex according to the seasons, and lower GSI values were observed in polluted stations in all three species. It was observed that HSI values in fish varied significantly from station to station. In addition, an increase in ovarian and testicular lesions (degeneration in oocyte and spermatocytes, atresia, congestion, infiltration, edema, vascular hypertrophy, fibrosis) was detected in the polluted areas. The results clearly showed that the metal pollution in the river adversely affected the reproductive system of the fish species living in the river.