Ganges River Dolphin
- EDGE Mammals Rank: 58.
- Occurs in the Indus, Ganges-Brahmaputra-Megna, and Karnaphuli-Sangu river systems of the Indian subcontinent.
- The sole survivor of a once diverse cetacean group that millions of years ago occurred across the world’s oceans.
- Extremely unusual looking with a needle-thin beak.
- It swims on its side and upside down and, being virtually blind, uses finger-like projections on its fins to find food along the bottom of the rivers in which it lives.
- Following the extinction of the Yangtze River dolphin, the Endangered Ganges and Indus River dolphins are now the most threatened freshwater cetacean species.
- Overfishing (including resource depletion, accidental by-catch, and direct exploitation for oil and fish bait).
- Water development projects, notably the damming of rivers for irrigation and electricity generation, degrades habitat, isolates dolphin populations and prevents seasonal migrations of dolphins and their fish prey species.
- Industrial, agricultural and domestic pollution is also likely to have a negative effect on dolphin populations through immunosuppression and increased mortality.
- Development of an improved scientific evidence-base on dolphin abundance, and the main factors driving population declines.
- Increased regional conservation capacity-building.
- Environmental education and awareness-raising.
- Protective environmental legislation.
EDGE aims to support the conservation of the Ganges River dolphin through assisting with the development of a long-term regional dolphin research and conservation management strategy, which will be sustained by continued engagement with local fishing communities.
One of the world’s few true freshwater dolphins, this ancient and remarkable mammal is found in the Indus, Ganges and Brahmaputra river systems of the Indian subcontinent. Although superficially similar in appearance – for example, having reduced eyes – because they have each evolved in similar riverine environments, the Asian river dolphins represent a convergent group of only distantly related species. They are the most threatened group of large mammals. The Yangtze River dolphin has recently become extinct, and the Ganges River dolphin is now facing the same future as a result of degradation of river systems, persecution for oil, and entanglement in fishing gear.
Surprisingly little is actually known about why Ganges River dolphins have disappeared from parts of their range, or the relative importance of different threat factors in driving dolphin population declines. The Brahmaputra River system in north-east India was until recently the last refuge to contain a relatively healthy dolphin population, but this population is also now in decline. ZSL is working with the Assam-based conservation organisation Aaranyak to develop a long-term dolphin conservation programme for the Brahmaputra River system. The programme is funded by the UK Darwin Initiative and involves community-based education campaigns, sustainable conservation management initiatives, and dolphin population monitoring. ZSL is also initiating a river dolphin programme in Bangladesh to conduct conservation research across the country’s main river systems. This project aims to identify the main causes of mortality in river dolphin populations, and in particular to establish levels of dolphin mortality in fishing gear.
