Electric forcefield rises to the top in trials of shark deterrent devices
A number of shark deterrent technologies have come to market recently, but there is still a lot to learn about how they perform in the heat of the moment. A new research project has pitted a set of commercially available systems for surfers against one another, with a device that creates an electronic forcefield around it coming out on top.
The project was carried out by researchers at Australia's Flinders University and Fox Shark Research Foundation, and saw five commercially available devices designed to deter sharks put to the test in Neptune Islands Group Marine Park off Australia's southern coast.
A shark deterrent wax called Chillax, along with bracelets, leashes and devices from Rpela, Sharkbanz and Ocean Guardian were used in the project. These latter three are designed to interfere with a shark's ultra-sensitive electro-receptive system and work by creating a low-frequency, three-dimensional electric field around the wearer or surfboard they are attached to.
When a shark enters the vicinity, the electric fields can cause them to experience muscle spasms and severe discomfort, in theory prompting their swift departure. Field testing in 2016 found the Ocean Guardian system, known as Shark Shield at the time, can repel 90 percent of attacks from great white sharks.
In the new research at Neptune Islands Group Marine Park, the scientists conducted 297 tests involving bait and 44 individual great white sharks, the species most responsible for fatal attacks in the country.
The project saw the sharks make a total 1,413 passes of the bait, with the Ocean Guardian's Freedom+ Surf device proving the most effective at fending them off. This is an antenna that fits onto the tail pad of a surfboard, and the researchers say that in their testing it reduced the chances of a shark taking bait mounted to a surfboard by almost 60 percent.
"We compared how many baits sharks took, the time they took to take them, the number of times sharks approached baits, and the distance they moved toward them," says Associate Professor at Flinders University, Dr Charlie Huveneers. "We found that the Freedom+ Surf, which produces a strong electric pulse, affected shark behaviour and reduced the chance of a white shark taking the surfboard-mounted bait from 96 percent to 40 percent."
The team says it found little evidence that the other devices tested in the project had an influence on shark behaviour, though that's not to say they are entirely ineffective. Each device was tested roughly 50 times, so it is possible that further trials could show them to have some impact.
The full report form Flinders University can be found online here and the video below shows how the testing was conducted.
Source: Government of Western Australia