Bhubaneswar: After demolishing the illegal prawn dykes, the Chilika Development Authority (CDA) on Monday started the removal of "zero nets" having mesh size less than 10mm at various eco sensitive areas of the lagoon.

A forest official said zero nets posed threat to the biodiversity of the lake.

A CDA official said dismantling of such nets was difficult and the authorities had hired around 50 labourers.

"Unlike prawn dykes, which are made up of big bamboos, the zero nets are fixed with small bamboos, which cannot be dismantled using excavators. Workers need to swim in the lake and dismantle the structure manually which is time consuming. We will also supervise the lake area to ensure that the prawn dykes don't come up again," said additional chief executive of the lake development authority Sasmita Lenka.

A forest official said that use of such nets was harmful for movement of aquatic species especially Irrawaddy dolphin (Orcaella brevirostris), a schedule-I animal under the Wildlife Protection Act 1972. "Youngspecies of fishes, prawns and crabs are caught using such nets which will hamper the fishing activity. Fishermen have rights to catch aquatic species but there are certain regulations which must be followed," Lenka said.

Around 2 lakh people depend on fishing from the lake in Khurda, Puri and Ganjam districts.

"The zero net eviction from the lake area will increase the fishable area and be beneficial for the mud crabs. Eviction of prawn dykes have also encouraged the fishermen community to use traditional traps instead of nets," said a forest official.