A study on the abundance and biodiversity indicators of fish in Dinor River, Kermanshah Province

The aim of this study was to determine the biodiversity indicators of fish in Dinor River, Kermanshah province. For this purpose, in July 2018, six stations were selected for fish sampling along the Dinor River, with Station 6 upstream and Station 1 downstream. Fish sampling was performed using an electroshocking device. In total, 2543 fish specimens were caught from the Dinor River, belonging to 20 species. In this study, most of the species caught belonged to the family Cyprinidae. Alburnus sellal and Capoeta trutta had the highest and lowest abundance among the studied species, respectively. In the present study, biodiversity indices including Shannon-Wiener, Margalf, and Simpson, species richness, dominance and homogeneity were determined. The results showed that the Shannon-Wiener and Margalf indices increased from the upstream stations (6 and 5) to station 4, but decreased after the fourth station. In relation to the Simpson index, the fourth station showed the highest value of this index, but then fell sharply in the third station. In terms of species richness, stations 6 and 4 had the lowest and highest species richness, respectively. Although Station 4 had the highest level of homogeneity among the studied stations, but after this station, a decrease in homogeneity was observed in the downstream sections, especially Station 3. In this study, the dominance index showed an inverse relationship with homogeneity, so that the dominance value was lowest in station 4 and reached its highest in station 3. Changes in biodiversity indices along the Dinor River can be due to land-use changes in the riparian zone, improper extraction of sand, as well as the entry of pollutants from agricultural, industrial and domestic wastewater into the Dinor River.