A study off the coast of Exmouth has discovered deterrent devices could reduce shark bite-offs by up to 65 per cent. The Department of Primary Industries and Regional Development research off the Exmouth coast and Montebello Islands tested the effectiveness of three deterrent devices. The devices tested were the magnetic Sharkbanz, electronic Ocean Guardian and acoustic SharkStopper. The study found the devices tested did not stop shark depredation occurring in each instance but the probability of fish lost to sharks was significantly lower when deterrents were used. Anglers revealed they used several methods to mitigate shark bite-offs, including rapid retrieval, heavier fishing line, electric reels, avoiding the use of burley or baits and not dumping fish offal. The Exmouth coast was chosen because the North West reported increasing occurrences of shark depredation in the past 10 years. Three devices were tested against a control of using no deterrents, with cameras attached to the fishing lines to capture the underwater action. Fisheries Minister Don Punch said the scientists indicated deterrent devices were effective in cutting shark depredation rates. “That rate reduced when multiple sharks were competing for catch on the fisher lines, so shifting fishing spots regularly was another simple way to reduce bite-offs,” he said. The research was funded by recreational licence fees.