The carcass of a Gangetic dolphin was recovered near Barari Ghat here on Sunday, raising fears it got caught in nylon fishing net and died.

Eleven dolphins have died in the Vikramshila Gangetic Dolphin Sanctuary in the past 10 months.

The autopsy of the 6.5ft male dolphin - weighing 120kg - was conducted on Sunday evening but the report is not yet available to forest officials here. "We hope this is a natural death, but only the report will confirm unnatural case, if any," a senior forest department official said.

Sources said the doctor who conducted the autopsy found some injuries on the body, suggesting it might have got caught in nylon nets used rampantly by the fishing mafia.

Bhagalpur divisional forest officer Sanjay Kumar Sinha was not ready to speak on the issue. "I will call you later," was his reply to this correspondent at least thrice on Monday.

Use of nylon nets for fishing in river water is completely prohibited in the sanctuary area but hardly anyone pays heed to it. It has been observed that in maximum cases, dolphins get killed after getting trapped in nylon nets, the sources said. "Fishing using nylon nets has been going on at the spot - hardly a stone's throw from Sundarvan, the office of the divisional forest officer - where the dolphin was found dead on Sunday," said Babai Banerjee, a nature expert.

"From time to time, we conduct raids on the river but owing to limited manpower and resources, we fail to do it effectively," a forest official admitted.

Arun Kumar, a local resident, said no management has been created for the protection of dolphins even 24 years after formation of the sanctuary over a stretch of 60km from Sultanganj to Kahalgaon.

"Last year, the state government constituted a separate Bhagalpur forest division, by bifurcating the Banka forest division, but officials concerned have not yet yet been able to stop illegal fishing by nets," he said.

Keeping in view the conditions here, the government had decided to ask the Patna unit of Geological Survey of India (GSI) to prepare blueprint for a management plan of this sanctuary, sources said. But, the sources added, the plan has been lying in cold storage for the past eight months and nobody knows its progress.

Dolphin expert and Tilkamanjhi Bhagalpur University senior teacher Sunil Kumar Choudhary has also expressed his serious concern over the episode.

"Unless illegal fishing with big nylon nets is stopped here, there is no other way to protect the dolphins at this sanctuary," he said.