Participating in a two-day seminar here on conservation of the Ganges River Dolphin, the experts said its numbers continue to dwindle alarmingly due to killing, pollution and the break-up of its habitat by building dams.
"Conservation of the Ganges River Dolphin should be given priority by all," Wildlife Institute of India director P.R. Sinha said. "It should be given the same importance as conserving tigers."
He was one of the dozens of national and international experts who attended the workshop Monday and Tuesday. It was organised by the working group for action plan for dolphin conservation, set up by the central Ministry of Environment and Forests to finalise India's dolphin conservation plan.
The group is likely to submit its report to the ministry by April.
"Conservation of the Ganges River Dolphin must be initiated on a massive scale because freshwater dolphins are found only in some countries in South America and Asia," said Randall Reeves, chairman of the International Union for Conservation of Nature (IUCN) cetacean (whales, dolphins and porpoises) specialist group.
IUCN has classified the species as endangered.
Reeves said one way to save the dolphins was to turn stretches of river where they were found into tourist spots, as had been done in South America.
Well-known expert on Ganges River Dolphins R.K. Sinha said dolphins are the lifeline of the Ganga (Ganges). "If the dolphin numbers increase in the river, it will be a positive sign for a clean Ganga and if the numbers decrease, it is a negative sign of increasing pollution," he said.
Experts discussed how to get Ganges River Dolphins the status of "indicator species" for gauging the success of Ganga cleaning mission. R.K. Sinha said that since dolphins were at the apex of the food chain in the river, their condition would help assess whether the steps taken to clean the river Ganges were working.
R.K. Sinha, who has been researching on freshwater dolphins for over two decades, asserted that immersion of idols in rivers after Hindu festivals poses a grave threat to aquatic life. He suggested that "man-made water bodies" be used for immersing idols.
"The Ganga is already highly polluted, and its ecosystem is under pressure. The immersed idols will create more trouble for dolphins and people dependent on the river for drinking water," said R.K. Sinha, a professor of zoology at Patna University.
Untreated sewage, rotting carcasses and industrial effluents that find their way into the Ganga during its 2,500-km-long journey from the Himalayas to the Bay of Bengal have also affected the dolphins, he said.
Bihar's Minister for Disaster Management Devesh Chand Thakur assured the experts that the state government was committed to conservation of Ganges River Dolphins. "The state government has decided to provide funds for conservation of the dolphins from the next fiscal year," Thakur told the experts during his address Monday.
The minister said an awareness campaign would be launched among fishermen and boatmen in the state for conservation of Ganges River Dolphins.
Experts at the conference estimated the current population of Ganges River Dolphins at around 2,000, with about half of these in Bihar and Uttar Pradesh. The World Wide Fund for Nature (WWF) says that in the 1980s, there were around 3,500 in the delta region alone.
According to WWF, the range of the Ganges River Dolphin covers seven states - Assam, Uttar Pradesh, Madhya Pradesh, Rajasthan, Bihar, Jharkhand and West Bengal. The upper Ganga (in Uttar Pradesh), Chambal (Madhya Pradesh and Uttar Pradesh), Ghaghra and Gandak (Bihar and Uttar Pradesh), Ganga from Varanasi to Patna (Uttar Pradesh and Bihar), Sone and Kosi (Bihar), Brahmaputra from Sadia (foothills of Arunachal Pradesh) up to Dhubri (on the Bangladesh Border) and Kulsi River, a tributary of the Brahmaputra, form its ideal habitats.
The Ganges River Dolphin is one of four freshwater dolphin species in the world. The other three are found in the Yangtze river in China, the Indus in Pakistan and the Amazon in South America.
The Ganges River Dolphin (Platanista gangetica) is found in India, Bangladesh and Nepal. In appearance, it is identical to the Indus River Dolphin.
WWF says Ganges River Dolphins prefer deep waters, in and around the confluence of two or more rivers. They share their habitat with crocodiles, fresh water turtles and wetland birds.
It has a sturdy, yet flexible, body with large flippers and a low triangular dorsal fin. It weighs up to 150 kg. The calves are chocolate brown at birth and become greyish brown in adulthood with a smooth and hairless skin. Females are larger than males. The maximum length of a female is 2.67 metres and of a male 2.12 metres. Females attain sexual maturity at 10-12 years, while the males mature earlier. The gestation period is 9-11 months and a female gives birth to only one calf, once in 2-3 years.
The Ganges River Dolphin is blind. It finds its way and and its prey in the turgid rivers waters through echo-location.