Fishing nets over ponds in Nadia to keep birds away have killed hundreds of them and led to an FIR against a farmer, ruffling feathers instead of ensuring bigger catches.

Fish-eating species like kingfisher are often trapped and many die after being entangled in the nets, bird lovers and nature care activists have said, describing the “traps as inhuman” and a threat to the “ecological balance”. The farmers say they are forced to use the nets to protect their fish from kingfishers, black cormorants, little egrets and wild goose.

“This is sheer cruelty. It is natural for some birds to hunt for fish. But birds cannot be punished this way,” said Subrata Biswas, joint secretary of Santipur Science Club that has filed the complaint against farmer Kartick Paul.

The bird lovers and activists have also launched an awareness campaign appealing to the fish farmers to remove the nets.

The club said it had to approach police after repeated persuasions by nature lovers failed to convince farmers to remove the nets in several areas of the district over the past four months.

The FIR against accuses Paul of killing birds. The police are yet to start investigations but have asked him to remove the nets. “I was forced to cover a portion of a canal with the nets as birds often steal my fish,” Paul said.

Told that many birds were getting caught in the nets and dying, Pal added: “If a bird is stuck in the nets, we free it and let it go. But some birds have died. The police have asked us to remove the nets. We are considering the directive.”

Biswas, the science club joint secretary, said he and other members had “found that over a dozen birds are trapped every day” in Paul’s nets. “They eventually die. Some escape with wounded wings or legs. They need to be protected. We tried to persuade Paul to remove the nets. But as he refused, we lodged the complaint. It is the duty of the police to protect birds under the Wildlife Protection Act,” Biswas added.

A Santipur police officer said action would be taken against Pal if he did not remove the nets.

Divisional forest officer (Nadia-Murshidabad) Rana Das said he had “no information about birds being killed this way”. “Awareness is needed more than legal action. It will help if the nature activists inform us about nets killing or trapping birds.”