Why in news?
The annual Ganges river Dolphin census was undertaken by the World Wide Fund for Nature- India in collaboration with the Uttar Pradesh Forest Department recently.
- The Ganges river dolphin was officially discovered in 1801.
- They are found in the Ganges-Brahmaputra-Meghna and Karnaphuli-Sangu river systems of Nepal, India, and Bangladesh.
- The Ganges river dolphin can only live in freshwater and is essentially blind.
- They hunt by emitting ultrasonic sounds, which bounces off of fish and other prey, enabling them to “see” an image in their mind (Echolocation).
- Females are larger than males and give birth once every two to three years to only one calf.
- The Gangetic river dolphin is India’s national aquatic animal and is popularly known as ‘Susu’.
- Vikramshila Gangetic Dolphin Sanctuary (VGDS) in Bihar’s Bhagalpur district is India’s only sanctuary for it.
- It is among the four freshwater dolphins in the world– the other three are:
- The ‘Baiji’ now likely extinct from the Yangtze River in China,
- The ‘Bhulan’ of the Indus in Pakistan,
- The ‘Boto’ of the Amazon River in Latin America.
- These four species live only in rivers and lakes and its presence indicates the health of the riverine ecosystem.
- Threats to them include pollution, poaching, construction of dams and barrages and noise pollution created by large ship propellers and by dredging.
- IUCN Status – Endangered