Shark expert deems repellent bands a ‘sugar pill’ after woman killed wearing device

A marine life expert has a blunt warning about wearable shark deterrents after a woman was killed in a shark attack despite wearing a magnetic repellent band.

The 65-year-old woman was swimming off the coast of South Africa when she was killed, raising fresh questions about claims the devices can protect swimmers from an attack.

WATCH THE VIDEO ABOVE: Shark repellent bands under scrutiny after fatal attack

Senior marine life ranger Sharky Baxter described the bands as little more than a “sugar pill”.

“It gives a sense of some sort of security, like if I’m wearing this I’ll be OK,” he told Sunrise on Friday.

“We know that there’s a history that people wearing the devices have been attacked by sharks.”

Not all shark deterrents are created equal

Scientist Maddy Massie said there were important differences between the types of wearable deterrents available, with electric devices having considerably more scientific evidence behind them than magnetic alternatives.

Electric deterrents work by interfering with a shark’s electrical sensing system, sending out a signal designed to confuse or overwhelm the animal and trigger avoidance behaviour.

Magnetic devices also aim to interfere with that system but Massie said there was far less evidence supporting their effectiveness.

“Unfortunately, it only works over a really close range. So, say less than 1m, which is not something that you want to be testing out,” she said.

While acknowledging there was some potential in the technology, Baxter said people should not mistake the devices for a guarantee of safety.

He questioned the commercialisation of the devices, saying sales could surge following shark encounters as worried swimmers and families rushed to buy them.

“Companies are making money. Every time there’s a shark encounter somewhere, sales go through the roof,” he said.

Could bigger technology offer better protection?

Massie said one of the challenges in testing shark deterrents was that the animals could have very different motivations for approaching people.

A shark that was strongly motivated by food and approaching at speed could be much harder to deter, she said.

Researchers also could not necessarily account for those motivations during testing, leaving uncertainty about how the devices would perform during an actual encounter.

“There’s a lot of uncertainty about whether these things really work,” she said.

Massie said scientists were also investigating whether the technology could be scaled up to create larger deterrent barriers, rather than relying on small wearable devices.

Baxter said he wanted to see more research directed towards solutions that could actively repel sharks from popular swimming areas.

“Imagine if it was as simple as having a big, thick boom that could float out the back of a swimming area and it’s thrown a pulse down of some sort that deters the sharks and reflects them away,” he said.

“That’s what we want to hear from the scientists.”

The free precautions swimmers should be taking

In the meantime, Massie urged people to consider ocean conditions and take responsibility for their own safety, including swimming between the flags and staying in larger groups.

She said the noise and vibrations created by a group of swimmers could encourage sharks to avoid the area.

“If we’re in a large group of other people, we’re creating a lot of noise and vibration in the water, a shark doesn’t really know what to do with that, and that can lead to avoidance behaviour,” she said.