Kolkata: Bengal, with 815 Gangetic dolphins, ranks third in the country, according to the first-ever estimate of the riverine dolphins in India.
Prime Minister Narendra Modi On Monday released the report during his visit to Gir National Park in Gujarat, where he chaired the 7th meeting of the National Board for Wildlife.
In Bengal, 12 rivers spanning 2,366 km were covered in 62 days as part of the survey of which, the Ganga River alone had a coverage area of 584 km that included areas like Rajmahal-Farraka barrage, Farakka barrage-Diamond Harbour, Diamond Harbour-Gangasagar, Farakka barrage-Nimtita (India-Bangladesh border).
The other rivers in the population estimation list are Mahananda (51 km), Rupnarayan (79 km), Mundeshwari (7 km) Bakshi Canal (6 km), Silabati (6 km), Dwarakeshwar (4 km), Torsa (55 km), Kaljani (21 km), Churni (10 km), Haldi (19 km) and 86 river channels under Sunderban Tiger Reserve (STR) and Sunderban Biosphere Reserve (SBR) with a total area of 1524 km.
The highest 519 dolphins were found in the Ganga River, with 429 in the Farakka-Diamond Harbour stretch, precisely between Agradwip to Nabadwip stretch (46 km) and Jangipur to Azimganj stretch (56 km). Rupnarayan too recorded a healthy population of 167, Mahananda 64, Mundeshwari 12, Bakshi Canal 21, Silabati 17, Torsa 1, Kaljani 5 and Churni 7.
In Sunderbans, two Ganges River Dolphins were recorded, while no dolphin was found in Darakeshwar and Haldi Rivers. However, the total Irrawaddy Dolphin estimates in Sunderbans are 108 with 94 under STR and 14 under SBR. Double observer method was followed in the survey. Interestingly, three mammal species that were sighted during the survey were the Golden Jackal, Plains Grey Langur and Indian Flying Fox. “The important areas identified in Bengal are crucial for dolphin conservation and improving local livelihoods. The dolphin population in Bengal has a significant concentration in the Rajmahal to the Gangasagar stretch and the Rupnarayan river. Key areas for conservation include the districts of Hooghly, North 24-Parganas, Malda, Murshidabad, Nadia, East Midnapore, West Midnapore and Cooch Behar. Notably, the Bakshi canal, part of the Rupnarayan River system, has a high encounter rate of dolphins (that was) 3.6 per km,” said an official in the state Forest department. “Dolphin is an integral part of the Integrated Development of Wildlife Habitats — a Centrally-funded scheme that aims to protect wildlife and its habitats. We have submitted a project related to dolphin conservation and are waiting for the nod of the Centre,” said Debal Roy, Head of Forest Force in Bengal.
The International Union for Conservation of Nature (IUCN) lists the Ganges River Dolphin as endangered.
Dolphins can only live in freshwater and have ultrasound vision. Given their poor eyesight and the muddy water around, they bump into boats easily. There are instances of dolphins getting caught in fishing nets and getting killed.
The survey found a total of 6,327 dolphins in 28 rivers in eight states. Uttar Pradesh recorded the highest number followed by Bihar.