Over 3000 fishing boats in major fishery centres like Kollam and Kochi will remain berthed to harbour during the ban period though there would not be restriction in fisherfolk venturing to the Arabian sea in country craft.
Fisheries Department has stepped up patrolling off the Kerala coast for effective implementation of the ban, an official statement said here.
Mechanised boats from outside the state had been directed to leave the coast.
Studies by scientific agencies have brought out that the monsoon-time ban on bottom-trawling, which has been in force for over two decades, has helped improve habitat of marine fish stock.