One of the four freshwater dolphins in the world, the Ganges River Dolphin, is an aquatic and endemic mammal found in the Ganga-Brahmaputra-Meghna river systems. The population of Ganges River Dolphin has declined rapidly in the last decade due to direct killing, habitat fragmentation due to dams and barrages, indiscriminate fishing and pollution in the rivers. The number of dolphins in this river system in 1982 was estimated to be between 4000-5000 in India but now it is less than 2000 with an annual mortality estimated to be 130-160 animals (Gupta, P.D. 1986). Listed by IUCN (The World Conservation Union) as ‘endangered’ , included in Appendix-II of CITES (Convention on International Trade in Endangered Species) and placed in Schedule I of Indian Wildlife (Protection) Act, 1972, the dolphin enjoys high levels of legal protection nationally and internationally. Yet its numbers continue to decline, in the absence of a coordinated conservation planning, lack of awareness, continuing developmental pressures and almost no protected areas for the species (Rao 1995).

Threats to dolphin habitats: ■ Pollution ■ Competition for water ■ Habitat alteration ■ Introduction of exotic species ■ Commercial exploitation

The Ganges dolphin is distributed in India, Bangladesh, Nepal, and Bhutan. The dolphins are graceful and docile mammals. The body of Ganges dolphin is fusiform, that is, its head tapers into a long compressed snout beset with pointed conical teeth arranged in a serial row. Its forehead is vaulted and compressed. Its blow hole is longitudinal. The eye is small and imperceptible. There is a depression between head and body, which marks the region of the neck. The dorsal fin has a fleshy ridge which occurs at the middle of the body. In the female, the dorsal fin is more distinct than in male. The tail fluke is horizontally placed. The male dolphin has a shorter snout and is more heavily built than the female. The general body colour is sooty black with light spots scattered on the sides. Females are usually bigger in size (1.7 to 2.5 m) than males (1.5 to 2 m). The body weight of females is also more (50 to 80 kg) than males (40 to 60 kg) (Behera, S.K. 1995).

The Ganges river dolphin is blind. To compensate the loss of vision, the animal has a very efficient echolocation capability. Being a mammal it cannot breathe inside water, so it surfaces every 30-120 seconds to breathe. Because of the sound it produces when breathing, the animal is popularly referred to as the Susu. These dolphins mostly occur singly, occasionally in pairs and rarely in groups (Behera, S.K. 1995).

Wildlife and People: Major Threats to River Dolphins

The habitat of Ganges dolphin in the Ganges-Brahmaputra-Meghna system comes within one of the most densely populated and food scarce area of the world. The biotic resources in the dolphin habitat are under severe threat of overexploitation by the local community (Behera, 1995). The population of Ganges river dolphins has depleted due to habitat destruction, commercial exploitation and incidental bycatch in fishing nets. The dolphins are hunted for meat and oil, both used medicinally and particularly the oil is used to attract catfish in the net fishery. The dams and barrages on the rivers have created a permanent barrier across the river, blocking the movement of the dolphins. The habitat destruction of dolphins is due to the presence of barrages, use of chemical fertilizers and pesticides in agricultural practices in the catchments, industrial pollution, and certain religious rituals. Large scale fishing activities were observed in the dolphin habitat at different areas. Due to the un-conventional fishing methods large quantities of fish were being caught as by-catch, so fish populations were depleted.

WWF’s efforts to help conserve the Ganges River Dolphin

WWF-India adopted Ganges River Dolphin as a species of special concern and initiated Ganges River Dolphin Conservation Programme in 1997, with following goals: