India’s First Comprehensive River Dolphin Survey

News: The Wildlife Institute of India, under the Union Environment Ministry, conducted the first-ever comprehensive population estimation survey of river dolphins in India between 2021 and 2023. This survey covered the main channels and tributaries of the Ganga and Brahmaputra rivers, as well as the Beas River in Punjab.

Key Findings from the First Comprehensive Dolphin Survey (2021-2023)

• The survey estimated the total population of Gangetic dolphins to be 6,324, with a range between 5,977 and 6,688 individuals.
• The study also found only three Indus River dolphins, all located in the Beas River in Punjab.
• The highest number of Gangetic dolphins was found in Uttar Pradesh, with 2,397 individuals. Bihar followed closely with 2,220 dolphins, while West Bengal recorded 815.
• Jharkhand had 162 dolphins, while Rajasthan and Madhya Pradesh together had 95 individuals. Punjab was the only state where Indus River dolphins were recorded, with a count of three individuals in the Beas River.
• The survey identified certain stretches of rivers where dolphin populations were either abundant (hotspots) or sparse (coldspots).
  • The Narora-Kanpur stretch in Uttar Pradesh was one of the coldspots, with an encounter rate of just 0.1 dolphins per kilometer.
  • Other coldspots included the Yamuna River (Kaushambi-Chitrakoot), the Sharda River in Pilibhit, and the Rapti River from Balrampur to Sidhharth Nagar.
• On the other hand, some stretches had a high density of dolphins. In Bihar, the Chausa-Manihar stretch spanning 590 kilometers had an encounter rate of 2.20 dolphins per kilometer, while the stretch between Manihari in Bihar and Rajmahal in Jharkhand recorded an even higher encounter rate of 2.75 dolphins per kilometer. These areas were identified as key habitats for the species.

About Gangetic River Dolphin

• The Gangetic River Dolphin is primarily found in the Ganges, Brahmaputra, and their tributaries in India, Bangladesh, and Nepal.
• These dolphins are almost blind and rely on echolocation to detect and capture their prey. They produce ultrasonic sounds that help them navigate and hunt in murky waters.
• These dolphins prefer deep waters, particularly around the confluence of rivers, where prey availability is higher.
• They are found across seven Indian states: Assam, Uttar Pradesh, Madhya Pradesh, Rajasthan, Bihar, Jharkhand, and West Bengal.
• The Gangetic River Dolphin is one of only four freshwater dolphin species found worldwide. The other three species include: Baiji Dolphin, Bhulan Dolphin, and Boto Dolphin.