Impacts of Jhimruk Hydropower Dam on Fish and Fisheries of Jhimruk River, Pyuthan, Nepal

Abstract

Dams are artificial designs which interrupt river natural discharge causing many changes to river’s characteristic and functions. This work assesses the impacts of dam on Jhimruk River by taking fish and water quality parameters as indicators. The fieldwork was done from May 2016 to February 2017 that included fish sampling by using local methods and fisherman and measurement of water quality parameters at three sites i.e. at dam, upstream and downstream. Altogether 17 fish species under 3 orders, 4 families and 10 genera were collected during the study period. Shanon- weiner diversity index showed highest diversity (2.43) of fish in dam area and lowest (1.63) was found in downstream. The study revealed that majority of fish species belonged to the family cyprinidae. The most common species was Channa orientalis followed by Barilius vagra, Puntius ticto, Barilius bendelesis. Two migratory fishes Tor tor and Neolissochilius hexagonolepis were found to be confined to downstream only. Various physical and chemical parameters of the water were found to be altered. Temperature (21˚C), water velocity (1.13 m/s), dissolved oxygen (6 mg/l) were found to be mostly altered during dry season. These ultimate changes was due to the less release of water from dam to downstream and also result in the variation of fish composition and fish diversity.