Swimming In Great White Shark Territory? You Might Want To Grab This.

Surfboard? Check.

Wetsuit? Check.

Wax? Check.

Personal shark deterrent? Got it.

“I used to only use my [Ocean Guardian personal shark deterrent] in areas known for sharks, but after a mate was taken by a shark, I use it all the time now,” an Australian surfer said, as he wrapped the black velcro around his ankle. “It takes that little niggle out of the back of my mind, helps you relax and just surf.” He’s not the only one wearing the unmistakable deterrent. People wearing ‘shark shields’ when swimming in Australian waters isn’t rare; in fact, Western Australia has a shark deterrent rebate for approved devices. And while no product offers 100% guarantee of protection from any species of shark, it provides that peace of mind to many. Currently there are three devices which have been independently tested and scientifically proven to significantly reduce the risk of a white shark interaction, with existing personal shark deterrents generally aiming to protect the user within a few meters (read more about personal shark deterrents here and here).

In contrast to personal electric deterrents, there is little evidence that other products are effective at reducing shark bites. Seeing this gap in our knowledge, a new study led by Flinders University experts has tested the effectiveness of a newly developed, long-range electric shark deterrent on white sharks.

Southern Shark Ecology Group researchers, led by researcher Madeline Riley, tested the 80 volts and 150 volts (V) versions of the novel Ocean Guardian BOAT01 products that are designed to protect a larger area (8 meters deep × 6 meters wide), or to be linked together for greater spatial coverage. The group traveled to the Neptune Islands, located off mainland South Australia, for these trials. A world renowned hot spot for the white sharks (Carcharodon carcharias), these predators reg­u­lar­ly for­age in the area for seals which make the rocky-cragged coves here their home. In fact, it’s Australia’s largest colony of fur seals, with half the Aus­tralian pop­u­la­tion breed­ing here. Best known as an excit­ing loca­tion to go cage div­ing with great white sharks, this spot was the perfect setting to answer their questions: “We did 116 experimental trials on 43 white sharks to assess the percentage of baits taken, the distance between the bait and shark, the number of passes [a shark did], and whether sharks reacted to the deterrent.”

“The results showed that white shark behavior was affected by both versions of the device, reducing the proportion of baits taken by sharks by up to 48%. However, the effects of these products on distance were small, with shark average distance to the bait being 2-3 meters (6.5-9.8 feet) even when the device was turned on,” says Riley, a PhD in Shark Bite Mitigation Measures. “Our findings provide further evidence that electric deterrents can reduce the risk of a shark bite but the limited effective radius of this product restricts its use to protecting areas within approximately 3 metres – which is similar to that of other previously tested electric deterrents.”

Marine ecologist Professor Dr. Charlie Huveneers, who leads the Southern Shark Ecology Group at Flinders University, says the manufacturer of the BOAT01 devices has since reportedly modified its circuitry and electrodes with the aim of producing a stronger electric field with higher voltage than the model tested in this study. But he does wonder whether this new modified BOAT01 can deter sharks from farther away than measured in this study. “[That] remains to be determined, and will likely depend on the extent of the electric field’s propagation,” he explains.

He concludes by saying the results from this study provide empirical evidence to policymakers and consumers which enable them to select and implement appropriate mitigation measures for their intended use.