They are known as sons of the river but the endangered dolphins in the Ganges continue to die of pollution and activities like fishing - with the latest incident reported from Bhagalpur in Bihar.
Official sources in the wildlife department said a dolphin was found dead near a bridge across the Ganges in Bhagalpur, about 200 km from here, last week.
"The dolphin is suspected to have been killed after it got trapped in a fishing net," an official said.
This was the fifth dolphin found dead in Bihar in the last one year, causing concern to conservationists and wildlife enthusiasts. Dolphin experts say the toll is higher but only a few incidents got reported because the carcasses are either buried or thrown into the river.
All the dead dolphins have been found in the Vikramshila Gangetic Dolphin Sanctuary. The sanctuary is spread over a 50-km area of river Ganges and was set up nearly a decade ago.
Wildlife experts say that most dolphins die after getting entangled in fishing nets. The mammals are also killed for their meat, skin and oil.
Alarmed over the dwindling number of the rare river dolphins in the Ganges, Bihar Chief Minister Nitish Kumar had announced a move to save the species last year. But things have hardly moved beyond government files.
"Nothing has happened at the ground level to save them," an official admitted on condition of anonymity.
R.K. Sinha, head of the zoology department at Patna University, said: "If we fail to save these mammals, the future generations may see them only in photographs."
He urged a clean up of the Ganges to save the animal. A rapidly shrinking Ganges, which Hindus consider holy, and the river's changing course are the other factors threatening the dolphins, said Sinha, who also heads the central government's dolphin conservation project.
Sunil Choudhary, another wildlife expert, said: "On paper conservation work is going on. But in reality the sanctuary has no formal conservation plan. Unless locals are involved in conservation and awareness is created, dolphins will continue to die."
Untreated sewage, rotting carcasses and industrial effluents that find their way into the Ganges during its 2,500-km-long journey across several states from the Himalayas to the Bay of Bengal have also affected the dolphins, he said.
The Ganges has already shifted its course near Patna. It now flows over two kilometres away from the city, thanks to silting and pollution.
Researchers estimate the dolphin population across India to be a little over 1,500. Half of these are found in the Ganges in Bihar. The numbers have dropped drastically over the past decades. In the 1980s, the Gangetic delta zone alone had around 3,500 dolphins.
In 1996, freshwater dolphins - locally known as 'sons of the river' - were categorised as an endangered species by the World Conservation Union (IUCN), a forum of conservationists, NGOs and government agencies.
The dolphins of the Ganges are among the four freshwater dolphin species in the world, the other three are found in the river Yangtze in China, in the Indus in Pakistan and in the Amazon in South America.