By Prof BC Choudhury
River dolphins are one of the apex predators in the riverine food chain, largely preying on small fish and, thus, helping in keeping the ecosystem in balance. The Gangetic river dolphins are of huge ecological interest as they are highly threatened. Their total population in the Ganga and the Brahmaputra rivers is around 2,000, and this population is restricted to small isolated pockets. Their population has been on the decline since the 1980s. During fishing, the dolphin is either caught accidentally, or killed for extraction of oil out of its blubber, which is used as fish bait. The greedy fishing methods leave very little food for them, making them an endangered species. At least one of the river dolphins, namely the Irrawaddy dolphin found in the Chilika Lake in Odisha, is in the critically endangered category. Damming of rivers prevents its migration, making the small isolated populations further genetically isolated. The ecological health of our rivers further threaten the survival of not only dolphins but also many other species. A national action plan by the Ministry of Environment and Forests is in place, at least for the Ganges. It needs to be supported and implemented by professional organisations and community involvement. In the Narora stretch of the Ganga and in protected stretches such as in Chambal and Gerwa, their populations are stable, even on the increase. Even though the river dolphins are in the common property resource regime of river systems some specific river stretches need to be protected.
Prof BC Choudhury heads the Endangered Species Management Department at the Wildlife Institute of India and specialises in developing conservation management and recovery plans for endangered aquatic and migratory wildlife.
Author image by Nalini Choudhury