Jornal de Biodiversidade e Espécies Ameaçadas

Assessment of Fish Assemblage in Highly Human Managed Reservoirs Located on River Chenab, Pakistan

Abstract

Firdaus Kausar, Umm e Aiman, Abdul Qadir and Sajid Rashid Ahmad

River Chenab is one of the highly hydrologically managed rivers in South Asia and facing several environmental issues related to human population growth, industrialization, agricultural advancements and rapid urbanization. These issues are the major threat to the fish diversity of the River Chenab. In this regard, the present study was designed to elucidate the fish diversity, distribution patterns, conservation issues at five artificial water reservoirs (barrages) during the pre-monsoon and post-monsoon season in river Chenab, Pakistan. A total of 5715 individuals was sampled belonging to 16 families. The Cyprinidae (56.9%) was most dominant family followed by Bagridae (7.34%), Cichlidae (5.25%), Schilbeidae (4.55%), Siluridae (3.33%), Ambassidae (3.15%), Clupeidae (3.09%). In Cyprinidae family, Salmophasia bacaila was the most abundant species with relative abundance (10.70%) followed by Osteobrama catio (7.52%), Puntius sophore (5.44%). Ailia coila, Bagarius bagarius, Ompok bimaculatus and Ompok pabda showed low relative abundance. Highest number of fish individuals were reported from the Qadirabad barrage (27%) and lowest from Khanki barrage (14%). Oreochromis niloticus is an exotic species was the fourth most abundant fish species and could be a threat to the local species. Six near threatened species (Ailia coila, Bagarius bagarius, Ompok bimaculatus and Ompok pabda) with restricted distribution, and one endangered species (Tor putritora) was recorded. Generally, small sized fish species were high in number as compared to large sized fishes indicating over fishing of commercial fishes from the barrages. It was observed that there are several other fishing activities reducing the fish number. Illegal and destructive methods of fishing, pollution, flow reduction, water diversion, habitat reduction and human population growth are putting pressure on the fish diversity of River Chenab. Illegal fishing and discharge of effluents without treatment must be addressed to improve the ecological balance of fish assemblage and water quality of the river Chenab