In Bangladesh, more than 900 fishermen have been arrested and Army deployed to patrol its waterways after introducing a temporary ban on catching Hilsa in an effort to save the hugely popular fish.Official sources said in Dhaka that anyone caught catching Hilsa faces at least a year in jail under a 22-day ban that began on October 12, the start of the breeding season.Some 60 per cent of the world's Hilsa are caught in Bangladesh.