In Kerala, the one and a half month long ban on trawling by mechanised fishing boats comes into force from midnight tonight. Over 4000 trawlers in the state will remain idle during this period. The annual ban, which started in 1988, is considered to be an important step in sustainable development of fish resources in Arabian Sea. The state government has announced that fishermen who are rendered jobless during this period will be given free ration and financial assistance.