A personal shark deterrent developed for surfers and divers in Western Australia has been found to prevent more than 90% of shark encounters.

Research by the University of Western Australia’s Oceans Institute found the commercially available electronic deterrent, Shark Shield, successfully repelled sharks from approaching a baited test rig.

The shield emits a strong electric field, which is designed to interfere with the shark’s electroreceptive system, a network of sensors on the shark’s head. It is widely used by divers in WA.

UWA conducted tests with reef sharks off the WA coast and with great white sharks off the coast of South Africa using two baited test rigs – one fitted with the deterrent device and one without. While all sharks touched or took bait from the control rigs, fewer than 10% touched or took bait from rigs carrying the Shark Shield.

At a press conference at UWA’s school of animal biology on Wednesday, Professor Shaun Collin, director of UWA’s Oceans Institute, said he was “very positive” of Shark Shield’s ability to deter sharks and said there may be potential for the technology to be employed in “an electric barrier of some kind” to protect larger areas, kind of like an invisible shark net. The results of the study will be published soon.



Collin said researchers also tested another commercially available electronic shark deterrent but it did not appear to have any effect on sharks.

The $1.9m study was funded by the Western Australian government and was part of its shark hazard mitigation policy, which was introduced in 2013 after the state had seven fatal shark attacks between 2010 and 2013.

Associate Professor Nathan Hart said researchers were given a broad remit to investigate “novel” methods of repelling sharks and also investigate the sensory range of sharks.

They tested the effectiveness of light, loud noises and bubbles, particularly bubble curtains, in deterring sharks. Of the three, only bubbles were found to have any effect on great white sharks – and even then the effect was limited to sudden, directed bursts of bubbles. Bubble curtains, which have been touted as a non-lethal alternative to drumlines, were initially effective but the sharks soon acclimatised.

Hart said they also debunked the myth that great white sharks were scared of orca screams, concluding it was the presence of orcas themselves and not their call that shooed sharks away.

Hart has already released research into why sharks might be attracted to surfers.

Researchers also developed a program that can differentiate between shadowy ocean objects to identify which blobs are sharks and which are dolphins or whales.

The program has been tested on images and video footage obtained from the Surf Life Saving and Channel 7 helicopters, which patrol Perth beaches.

University of Western Australia researchers discuss their findings on shark deterrents.

Professor Mohammed Bennamoun, the computer scientist in charge of the project, says the program uses artificial neural networks to classify objects into shark and non-shark, removing the need for a person to manually check the footage.

Bennamoun said there was potential for the program to be used as a shark detection system, but said that while tracking of “marine objects” can be delivered in real time, the processing time for the shark classification algorithm meant there would be a delay in determining whether or not the object was a shark.

He added, “because the accuracy is never 100%, you would probably have to have a person to double-check and make sure it’s really a shark”.

WA has been criticised for its inhumane anti-shark policies and was accused of attempting to “cull” sharks with its controversial drumlines policy, which saw baited metal hooks set around Perth beaches. That program has since been scuttled by the Environmental Protection Authority, but the government retains the right to kill large sharks that have been deemed a “serious threat” by a fisheries officer.

Speaking at the press conference announcing the results of the research on Wednesday, the WA premier, Colin Barnett, said his government would retain the “serious threat” policy despite advancements in non-lethal shark deterrent methods.

“I know that’s not necessarily popular, but I think, imagine the public outcry if a child was taken by a shark,” he said.

Barnett also said he would not back the state opposition’s policy of offering subsidies for Shark Shields, which retail for between $600 and $750.

“If people wish to buy equipment to go out diving and surfing, that’s their responsibility,” Barnett said. “The government’s role is to make sure as much information is available about their effectiveness as possible.”

Barnett could not say whether improved shark detection, using the new shark classifier program, would result in more sharks being declared a “serious threat” and killed.

He said the government would continue to fund shark research and other, less humane, shark deterrent policies, both to maintain public safety and preserve WA’s tourism industry, adding, “we don’t want to gain a reputation as being the shark capital of the world”.