The first-ever comprehensive dolphin population census conducted in India found that India has 6327 river dolphins across eight states, with 6,324 Gangetic dolphins in the Ganges and Brahmaputra river basins and three Indus river dolphins in the Beas river basin in Punjab. The study was carried out between 2021 and 2023 and included a 101 km section of the Beas River and 8,406 km of the Brahmaputra and Ganga river basins, including tributaries.

Prime Minister Narendra Modi announced the survey, which was conducted as part of Project Dolphin, at the 7th National Board for Wildlife meeting in Gir National Park. Project Dolphin was started on August 15, 2020, to protect marine and freshwater dolphins. Participants in the study included the Wildlife Institute of India, state forest agencies from eight different states, and groups such as the Wildlife Trust of India, Aaranyak, World Wildlife Fund, and Turtle Survival Alliance.

A total of 6,327 Gangetic dolphins were estimated in the report, including 5,689 dolphins (range: 5,371-6,024) in the Ganga and 635 in the Brahmaputra. Uttar Pradesh (2,397) had the largest dolphin population, followed by Bihar (2,220), West Bengal (815), Assam (635), Jharkhand (162), Rajasthan and Madhya Pradesh (95), and Punjab (3), according to the report.

River-wise and Regional Distribution of Dolphins

3,275 Ganges dolphins were discovered in the Ganga’s main stem, 2,414 in its tributaries, and 584 in the Brahmaputra. Road surveys recorded thirty more river sections, and 28 rivers were surveyed by boat for direct population assessment.

A survey of 7,109 km of the Ganga was conducted, encompassing important tributaries such the Chambal, Yamuna, Ghaghara, Gandak, Rapti, Sharda, Kosi, Mahananda, and others. The biggest population of dolphins was found in a 47-kilometer section of the Chambal River in Uttar Pradesh between Bhind and Pachnada. The 366-km Narora-Kanpur section saw nearly no dolphins, while the 380-km Kanpur-Vindhyachal length had an encounter rate of just 1.89 dolphins/km.

Because of the favorable river shape and tributary effect, Bihar has a healthy population. With 1,297 dolphins spread throughout 590 km, the Chausa-Manihari stretch of the Ganga is one of the densest dolphin habitats.

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Conservation Challenges and Future Prospects

According to Schedule I of the Wild Life (Protection) Act of 1972, the Ganges (Platanista gangetica) and Indus (Platanista minor) river dolphins are both listed as endangered. Although their populations have significantly decreased as a result of human activity, they are bioindicators of healthy river ecosystems.

At the end of the 20th century, there were about 4,000–5,000 Ganges river dolphins, but by the end of the century, that number had fallen to about 1,800. Intentional killings and bycatch have resulted in at least 500 documented deaths since 1980. The main concerns are still habitat loss, pollution, decreased river flow, sand mining, and net entanglement.

Dolphins favor environments with deeper water, meanders, confluences, and mid-channel islands, according to the survey. Their travel patterns and breeding habits, however, are poorly understood. The Beas River is the only habitat for the critically endangered Indus River dolphin population in India, which urgently needs conservation measures.

The survey, which identifies key dolphin habitats and potential threats, reveals that India has 6327 river dolphins across eight states. Project Dolphin aims to connect scientific research with local communities to enhance conservation efforts and ensure the survival of these dolphins.

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