Two fishing trawls, used by the intruders to carry out unlawful fishing activities in the sanctuary, were also seized by the patrolling unit near Babuballi Island, a forest department official said.
The arrested fishermen hail from Paradip in Jagatsinghpur district, the official said, adding that the fishing vessels had trespassed into the prohibited corridors contravening the provisions of Wildlife Protection Act, Orissa Marine Fishing Regulation Act and mandatory rules of marine sanctuary.
Sea patrolling is stepped up along the Gahirmatha marine sanctuary between November and May every year in view of the annual mass nesting season of endangered olive ridley sea turtles.
Last year, about 6.04 lakh female turtles had turned up at the sanctuary to for nesting, Acharya added.