Drum lines

A drum line is an unmanned aquatic trap used to lure and capture large sharks using baited hooks. They are typically deployed near popular swimming beaches with the intention of reducing the number of sharks in the vicinity and therefore the probability of shark attack. Drum lines are often used in association with shark nets, used to offer further protection by enclosing designated swimming areas. The combination of drum lines and shark nets has been successful in reducing shark attacks in the areas protected by them. Since the shark nets and drum lines have been put into use (in the 1960s) there has only been one death caused by a shark attack on a protected beach. In January 2014, drum lines were introduced in Western Australia to catch potentially hazardous sharks. The topic of shark culling became a nationwide controversy and sparked public demonstrations and vocal opposition, particularly from environmentalists, animal welfare advocates and ocean activists.

The drum line consists of a floating drum (a barrel) with two lines attached to it. One line is attached to an anchor on the sea floor, while the other features a large baited shark hook. The drum is filled with a rigid polyurethane foam, which keeps it buoyant and prevents it from being stolen for use as a storage vessel. To attract sharks, the hooks are baited with red mullet and false jacopever. Since the objective of the drum line is to prevent sharks from approaching popular beaches (and not to attract them) only about 500 grams of bait is added to each hook. Thus sharks are only attracted to the baits from the immediate vicinity.

Drum lines were deployed to prevent shark attacks in Queensland, Australia in 1962. They continue to be used in Queensland, and continue to kill sharks (and also kill by-catch species such as dolphins). They were then used by KwaZulu-Natal (South Africa) and have been killing sharks there for the past 50 years. They were used intermittently in Western Australia in an "imminent threat" policy, having previously been used there for 4 months in 2014. However the use of drum lines ceased in March 2017 following a change in the state government. Since 2014 Réunion Island has used drum lines in conjunction with shark barriers.

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Wikipedia