Members of the government’s dolphin conservation committee and task force have raised an alarm over the rampant illegal fishing in Vikramshila Dolphin Sanctuary in the district.

On Tuesday, the team, led by its president R.K. Sinha, began a month-long inspection of the dolphin sanctuary in the Ganga — the one of its kind in Asia — from Kahalgaon to Bhagalpur. After studying the habitat of the aquatic mammals, they expressed concern over the rampant fishing with banned fine nets.

Arvind Mishra, a member of the task force, said: “We have been assigned with the task of conducting survey in the river and studying the flora, fauna and the dolphins. After conducting the survey in the Ganga and the Gandak, we shall submit our report to the state government by December-end.”

He added: “Fernando Truzelo, a research scholar from Colombia in South America who has experience of researching river dolphins in the Amazon, has joined our team. He, too, is of the opinion that illegal fishing poses a major threat to the dolphins.”

Sources said the task force president, Sinha, told the fishermen to not use the banned nets because not only small fish, on which the dolphins feed, are caught in these, the meshes also injure the mammals. The fishermen in Kahalgaon claimed that the fishing mafia were responsible for the illegal activities.

Yogendra Sahani, state co-ordinator, Jal Shramik Sangh (an organisation of fishermen and boatmen), said: “The powerful fishing mafia enjoy monopoly over the Ganga in Bhagalpur and other districts. They use dolphin oil to attract smaller fish to the nets.”

Another fisherman, Ashok Sahani, said: “The fishing ma-fia use the banned nets. They also enjoy monopoly over smaller streams and inland rivers. They catch thousands of fish illegally everyday.”

Asked about the allegations of illegal fishing in the Ganga, a forest department official on the condition of anonymity said it was difficult to survey the river completely because of paucity of manpower.