Qualitative assessment of Gheshlagh and Gavehrud tributaries in the Javah dam ecosystem based on biological indicators with an emphasis on fish fauna

The current research was conducted in 2021 in 5 stations in order to investigate the quality of water before the operation of Javeh Dam in Kurdistan Province. Sampling of fish and Macrobenthos was done using an electrofishing device and Surber sampler, respectively. A total of 13 fish species were identified, which belonged to 3 families: Cyprinidae, Mastacembelidae and Nemachielidae. Out of the total of 2003 fish caught in all the stations, more than 96.6% belonged to the Cyprinidae family. The highest relative frequency of 32.4% belonged to Capoeta damascina species. In addition, 2 exotic species, Carrasius auratus and Carrasius gibelio had an abundance percentage of 1.4. The diversity of fish species decreased from station 1 (upstream) to stations 2 and 3, which was probably influenced by human activities such as various types of pollution, but in station 5 of It had the maximum amount, which is due to the change in habitat conditions, such as the increase in flow rate and water depth. The results showed that the species diversity of fish had changes in different seasons, so that its minimum was estimated at 0.91 in winter and its maximum at 1.29 in summer. Macrobenthos included 10 families Chironomidae, Lumbriculidae, Simulidae, Baetidae, Hydropsychidae, Erpobdelidae, Glosiphonidae, Gamphidae, :union:idae and Potamidae. The classification of water quality based on the Karr ecological integrity showed that stations 1 and 4 were placed in the good quality class with a numerical value of 40 and 42, respectively, and stations 3 and 5 were placed in the very low and medium water quality classes with a numerical value of 9 and 34, respectively. In this way, it is necessary to manage and organize all sources of point and non-point pollutants in Gheshlagh and Gavehroud tributaries.