RESEARCHERS have found evidence not all shark repellents are simply fanciful rehashes of a low-budget 1960s-era Batman episode, with at least one new piece of technology effective at driving off the underwater predators.
University of Western Australia researchers put new product Shark Shield to the test off South Africa to see if its electronic emissions would discourage sharks from attacking.
They found the device that can be attached to surfboards or swimmers' legs produced an effective deterrent field averaging 1.3m from its electrodes.
Trials revealed great white sharks were deterred from interacting with a static bait 10 out of 10 times on their first approach.
Only after subsequent approaches did the rate drop to nine out of 10 times, with the average avoidance field dropping an average of 12cm with each approach.
Despite the increase in tolerance, the sharks still avoided biting or interacting with the static bait if the device was attached and switched on.
UWA lead researcher Dr Ryan Kempster said only one shark interacted with the bait once the Shark Shield was operating - a positive result for the product considering 322 individual encounters were observed.
"Although the effectiveness of the Shark Shield likely varies between species, the fact that white sharks are implicated in the majority of fatal incidents globally suggests that a deterrent that effectively deters this species should be an important safety consideration for ocean users," Dr Kempster said.
"The research found no evidence that the Shark Shield attracted sharks from a greater distance - a common belief among surfers and showed that the Shark Shield can reduce white shark interactions."
Professor Shaun Collin from UWA's Oceans Institute and the School of Animal Biology confirmed the test results.
"The research provides quantitative evidence of the effectiveness of the Shark Shield, its electrical field characteristics and its influence on the behaviour of white sharks," Professor Collin said.
"Our approach represents an accurate method for testing the effectiveness of shark deterrents that future research can adopt.
"It is important that robust scientific evaluation of these types of devices is carried out so that the public can make more informed decisions about how they can reduce their risk of encountering a shark.
"This device is no guarantee of 100% protection from any species of shark but at present, under the conditions we tested it, the Shark Shield is the most effective shark deterrent device currently on the market."
The research was funded through a $220,573 grant from the Western Australia Government.
The device relies on the 1995 discovery that sharks have a heightened sensitivity to close-range, low frequency electrical fields. -ARM NEWSDESK