In an exceptional discovery, a group of Gangetic River Dolphins has for the first time been spotted in the Mahananda river, situated in the Kishanganj district of Bihar. It was during a survey conducted by a team of scientists from Vikramshila Biodiversity Research and Education Centre (VBREC) of Tilka Manjhi Bhagalpur University that this discovery was made.
About Mahananda River
Mahananda river is a tributary of the Ganga. The river has its origin in the Himalayas in Darjeeling, West Bengal, and flows through Bihar and West Bengal, before joining the Ganga at Godagari in Bangladesh.
Scientists speculate that the number of dolphins in the Mahananda and its tributaries could potentially be higher than currently estimated. This assumption is due to the fact that the survey was not performed during the most suitable season, which is post-monsoon when water levels are optimal. The presence of these dolphins is an indication of a healthy river ecosystem.
Gangetic Dolphins: An Overview
Gangetic Dolphins, recognised as India’s national aquatic animal, can commonly be found in parts of the Ganges, Meghna, and Brahmaputra river systems in India, Nepal, and Bangladesh. They have a local name, “Susu”, given for the distinctive sound they make while breathing.
| Species Name | Habitat | Status |
|---|---|---|
| Gangetic River Dolphins | Ganges, Meghna, Brahmaputra river systems | Endangered |
| Amazon River Dolphins | Amazon river | Endangered |
Behaviour and Habitat of Gangetic Dolphins
Interestingly, Gangetic Dolphins are generally blind and can only determine the direction of light. They use an ultrasonic sound to reach their prey. This function helps them to navigate, feed, escape danger, find mates, breed, and nurse babies. These dolphins inhabit regions with little or no current, which conserves their energy. They typically prefer water that’s at least five to eight feet deep.
Issues Faced by the Action: Threats to Gangetic Dolphins
The primary threats to these creatures arise from declining water levels in rivers due to climate change, large-scale industrial and municipal waste discharge, siltation, and mechanised boats. Furthermore, they’re regularly hunted by poachers, with their carcasses frequently found on river banks.
Protection Status and Measures
According to the International Union for Conservation of Nature (IUCN), Gangetic Dolphins are classified as endangered. They’re listed on CITES Appendix I and are under Schedule 1, Wildlife (Protection) Act, 1972, which provides absolute protection, with offences under these carrying the highest penalties.
The Gangetic River Dolphin in a Global Context
The Gangetic river dolphin is just one of four freshwater dolphin species that exist globally. The others include the Yangtze river dolphin in China, the Indus river dolphin in Pakistan, and the Amazon river dolphin in South America, also known as boto or ‘pink river dolphin’ characterized by its long snout and light pink hue.
Vikramshila Gangetic Dolphin Sanctuary
Located in Bhagalpur District of Bihar, India, the Vikramshila Gangetic Dolphin Sanctuary covers a 50km stretch of the Ganges River from Sultanganj to Kahalgaon. Established in 1991, it is a designated protection area for the endangered Gangetic dolphins.
