Characterization of artisanal fisheries in Nepal and potential implications for the conservation and management of Ganges River Dolphin (Platanista gangetica gangetica)

The Ganges River dolphin (Platanista gangetica gangetica) (GRD) is classified as one of the most endangered of all cetaceans in the world and the second scarcest freshwater cetacean. The population is estimated to be less than 2,000 individuals. In Nepal’s Narayani, Sapta Koshi, and Karnali river systems, survival of GRD continues to be threatened by various anthropogenic activities, such as dam construction and interactions with artisanal fisheries. A basic description of the geographic scope, economics, and types of gear used in these fisheries would help managers understand the fishery-dolphin interaction conflict and assist with developing potential solutions to reduce interactions between GRD and local fisheries in Nepal. The main purpose of the study was to collect fishery and socio-economic information by conducting interviews with local fishermen in the Narayani, Sapta Koshi, and Karnali river systems. Based on interviews (n = 163), 79 percent of Nepalese fishermen indicated fishing for local species (e.g., mullet [Rhinomugil corsula] or siloroid catfish [Bagarius bagarius]) was their primary form of income. Fishermen reported fishing effort was greater in summer than winter; greatest in the afternoon (1430 hrs ± 0.27) and during low water level conditions; and gear was set 4.8 ± 0.2 days/week. Fishermen reported using eight different types of monofilament nets (gillnets and cast nets). Sixty percent used gillnets less than 10 m long, and less than one third preferred gillnets between 10 and 100 m long; a few used gillnets longer than 100 m. Fishermen usually set their gear close to their village, and about 50 percent preferred to fish in tributaries followed by the main channel behind sandbars and islands, and the main channel near a bank. Fishermen reported seeing more GRD in the main river stem in winter. In summer, fishermen spotted more GRD in tributaries. Most fishermen told us they believed education, awareness, and changing occupations were important for GRD conservation, but they indicated that occupational options were currently limited in Nepal. Nepalese fishermen acknowledged that fisheries posed a risk to GRD, but they believed water pollution, and dam/irrigation development were the greatest threats.