Swimmer who vanished at Lovers Point was sporting a shark deterrent. What science says about what they do — and don’t do – The Press Democrat

After a shark attack injured one of their own nearly three years ago, members of the Kelp Krawlers — who swim weekly round Lovers Point in Monterey County — started trying to find one thing which may make the open ocean really feel safer.

They turned to wearable shark deterrents, together with magnetic ankle bands designed to overwhelm a shark’s electroreceptors — the delicate “sixth sense” pores the predators use to detect the faint electrical heartbeats of close by prey. Other merchandise available on the market depend on electrical currents, whereas some use scent.

Erica Fox, a seasoned triathlete and Kelp Krawlers member, was sporting one such gadget Dec. 21, 2025, when she was found dead. Her physique was found alongside the Davenport shoreline in Santa Cruz County, about 25 miles from the place she was final seen.

Fox’s demise — now beneath investigation and suspected to have concerned a shark — has sparked scrutiny amongst swim membership members about whether or not the units meaningfully cut back danger.

A Santa Cruz County Sheriff’s Office spokesperson mentioned the company couldn’t verify whether or not an post-mortem had been carried out or whether or not Fox had suffered a shark chunk.

Witnesses reported seeing a shark breach simply offshore at Lovers Point that morning, the place Fox was main a gaggle of a few dozen swimmers. Many of them had bought Sharkbanz-branded merchandise after a 2022 assault injured fellow Kelp Krawlers member Steve Bruemmer, who survived however suffered severe accidents.

Sharkbanz is among the many most well known manufacturers in a discipline of shark deterrents marketed to swimmers, surfers and divers. Other corporations embrace Ocean Guardian, Rpela and SharkOff, every claiming its product can repel sharks utilizing electrical, magnetic or electromagnetic fields.

Although deadly shark assaults are extraordinarily uncommon, sharks — together with nice whites — and their prey are widespread alongside California’s coast, making the state a pure marketplace for merchandise promising added safety.

Sharkbanz, for instance, says its bands can deter nice white sharks which are merely “investigating” prey, as a result of the predators depend on electroreception whereas swimming in open water. The firm additionally acknowledges on its web site that the product does little to discourage ambush assaults when nice whites strike at excessive speeds from beneath.

“Sharkbanz does not claim to eliminate shark bite risk or provide a specific percentage reduction,” the corporate informed this information group in an announcement Friday. “Shark encounters are rare, unpredictable events influenced by many environmental and biological factors, making precise risk-reduction figures scientifically unrealistic for any personal deterrent.”

Despite its limitations, Sharkbanz markets its product as “proven, effective and safe,” and says it “reduces the risk” of shark encounters by emitting electromagnetic fields.

Australian-made Rpela, a tool that attaches to surfboards, says its product “makes it extremely unpleasant to be around,” including that “extensive testing has been carried out with predatory sharks with outstanding results.” SharkOff makes use of a low-voltage discipline meant to make sharks “jerk away” from the gadget, whereas Ocean Guardian claims its product causes “harmless but unbearable spasms” that immediate sharks to swim away.

Independent analysis has forged doubt on a lot of these claims.

A 2018 Flinders University examine in Australia tested five personal shark-bite deterrents — Freedom+Surf by Ocean Guardian, Rpela, Sharkbanz bracelet and leash, and Chillax Wax — throughout almost 300 open-ocean trials. Only one electrical gadget, Freedom+ Surf, diminished shark interactions by greater than half. The different merchandise confirmed little or no measurable impact.

Sharkbanz disputed the examine’s relevance to its merchandise, saying the testing situations weren’t designed to judge wearable magnetic units as they’re meant for use.

“The use of a large, highly attractive tuna bait suspended well beyond the effective range of permanent magnets represents an extreme, worst-case scenario,” the corporate mentioned.

Rpela additionally disputed the findings, citing an impartial 2021 examine printed within the Journal of Marine Science and Technology-Taiwan that discovered its redesigned “v2” mannequin diminished the chance of nice white shark bites by 66% and general interactions by 38%.

More just lately, Carl Meyer, a analysis professor on the Hawaiʻi Institute of Marine Biology, has been learning a number of wearable shark deterrents, together with Sharkbanz.

One key limitation, Meyer mentioned, is the extraordinarily small vary of the electromagnetic discipline the units emit — a spread sharks are unlikely to detect till they’re already very shut.

“A shark has to be within about 3 feet to even detect the field from a Sharkbanz bracelet,” Meyer mentioned. “At that distance, the field strength is well within the range of natural electromagnetic signals sharks routinely encounter. There’s nothing inherently alarming about it.”

Meyer additionally criticized how such merchandise are marketed, notably the repeated use of phrases like “reduce the risk.”

“Mainstream safety products typically provide clear, quantitative risk-reduction numbers, which I have not seen for this device,” he mentioned.

Sharkbanz mentioned that whereas magnetic deterrents have limits, impartial, peer-reviewed research have proven they’ll alter shark habits at shut vary, together with “avoidance and reduced engagement with targets.”

Many of Fox’s fellow swim membership members mentioned they have been conscious of the analysis — and its limitations.

“All of us will openly admit that we hold on to certain things, knowing that it gives us a false sense of security,” mentioned Lisa Jensen, who swam frequently with the Kelp Krawlers. “But we do it anyway.”

Jensen and fellow swimmer Sharen Carey mentioned a membership member contacted Sharkbanz after Bruemmer’s assault in 2022, when he was pulled underwater by an awesome white for about 12 seconds.

“They offered all of our members a discount code,” Carey mentioned. “And so, of course, we all got them.”

Carey mentioned she believes the anklet Fox wore was additionally a Sharkbanz. “It looked like mine,” she mentioned.

Sharkbanz mentioned it was saddened by Fox’s demise however had been “very straightforward” with the group in regards to the limits of its know-how, pointing to an e-mail to a gaggle consultant that mentioned “there is no effective way to prevent this type of ambush attack.”

The firm mentioned it likened the bands to seat belts or bike helmets, that are “intended to reduce the risk of harm, but they cannot protect someone fully, all the time.”

After researching the product herself, Carey mentioned she understood the band supplied little safety towards the form of ambush assault she feared most at Lovers Point. She wore it anyway when she swam with Fox and the group that morning.

“I’ve never gone into the water consciously saying to myself, ‘I don’t need to worry about sharks, because I have this band on,’” Carey mentioned. “So why do I wear it? That’s a really good question, isn’t it?”