Abstract

Aquatic biodiversity is in crisis due to several natural and anthropogenic factors. This study was conducted to find out the species diversity and to identify threats to the fish fauna in Narayani River system, Nepal. Both primary and secondary data collection methods were used in the study. Primary data was collected by reconnaissance survey and field monitoring and secondary data were collected from literature review from research reports, journal articles and books, records from Department of National Park and Wildlife Conservation (DNPWC), Chitwan National Park (CNP), National Trust for Nature Conservation (NTNC) and other stakeholders and from relevant websites. Various sampling sites were chosen based on availability of water resources, stakeholder consultation and the habitat preference of the fish species in that river system. Catch and release method was used in field to account the species diversity of fish. Ten orders of fish i.e. Clupeiformes, Cypriniformes, Siluriformes, Angujilliformes, Beloniformes, Ophiocephaliforms, Synbranciformes, Perciformes, Mastacembeliformes, Tetrodontiformes were found in the area. Under these ten orders, 25 families and 86 species were identified. Among the orders, Cypriniformes had the highest number of species while in families; Cyprinidae had the highest number of species (41%) out of total 25 families. Both natural threats (silt deposition, flooding) and anthropogenic threats (illegal fishing, construction of dam/bridge, waste dumping and poisoning to fish) to fish were found in the study sites. It is suggested to construct appropriate ladder during dam construction, stop dumping in the river and further study on fish diversity and threats to fish.