As great white sharks become more prevalent in Massachusetts waters, Vineyarders find themselves facing the ghost of the blockbuster filmed here 44 years ago. However low the probability, death or grievous injury from a white shark bite is a real and present danger in the Bay State, as events this past summer have proved. White sharks linger around the Cape and the Islands into November, and while in real life they don’t exhibit the cinematic devilry showcased in “Jaws,” a film roundly criticized for vilifying the huge fish, they do make mistakes with horrific consequences for those on the receiving end of their serrated teeth.
As The Times reported in October, a South African company has developed a faux-kelp screen meant to cordon off beaches and surf zones from sharks. Even if such preventive measures were deployed in Vineyard waters, many Islanders who dive, kayak, or row would routinely find themselves outside such a protected zone. Amanda Wilson, an owner of Ocean Guardian, an Australian shark deterrent maker, may have an answer. Wilson pitched her company’s devices, which are mobile, to some Island officials Monday morning at the Gannon and Benjamin boatyard in Vineyard Haven.
Wilson’s devices generate electromagnetic fields around their users. When a shark encounters the field, ampullae of Lorenzini in its snout — jelly filled pits that detect electricity — go haywire and distress the fish, causing it to steer clear of the field, according to Wilson. Ocean Guardian has crafted devices for use on surfboards and kayaks, in addition to ones for use by divers and swimmers. The type divers and swimmers use employs a wire or antenna that trails the user. Wilson said the swimmer and diver models emit a 15-foot to 20-foot electromagnetic sphere, while the surfboard unit emits a 10-foot to 12-foot electromagnetic zone.
Abalone divers in South Africa and Australia and sea urchin divers in California regularly use Ocean Guardian devices, Wilson said. Without the protection of a cage or an electromagnetic deterrent, Wilson noted, abalone divers previously had a high rate of mortality from white sharks.
Wilson said the device has undergone four comprehensive studies, and as a result, is the only scientifically proven device of its type in the world.
“Ocean Guardian’s government-approved and patented technology creates a powerful three-dimensional electrical field which causes unbearable spasms in these sensitive receptors, turning sharks away, including great whites,” Lindsay Lyon, CEO of Ocean Guardian, wrote in an email.
At Gannon and Benjamin, West Tisbury Police Chief Matt Mincone asked if the device could be used to move a shark away from a rescue scene. Wilson said it can be used that way, and that Florida lifeguards and first responders employ Ocean Guardian devices to disperse bull sharks during marine rescues.
Massachusetts Division of Marine Fisheries senior fisheries scientist Greg Skomal, a noted white shark expert, told The Times he saw merit in Ocean Guardian devices, but was unsure how the safety the device provides could accurately be boiled down to something like a percentage. Skomal was also unsure of the efficacy of the device when white sharks, which he described as “ambush hunters,” are in attack or hunting mode, as opposed to merely circling somebody wearing such a device. He said he would be interested in seeing studies involving towed seal decoys, because the sharks hit decoys with such committed velocity, it would be telling if the device performed under such circumstances.
When asked if such studies existed, Ocean Guardian spokesperson Rachel King said they did, and shared video evidence.
Wilson backed up the value of those studies, and played video for those gathered at Gannon and Benjamin. She also emphasized Ocean Guardian deterrents were developed with shark conservation in mind — as an alternative to drum lines and cordon nets that kill sharks.
As Australian Geographic reported in 2016, research conducted by the University of Western Australia showed under some conditions, Ocean Guardian devices (previously known as SharkShield) can approach 100 percent effectiveness.
Ted Box, builder of the scow Seeker, told Wilson his vessel will be used for a lot of children’s in-water activity. He asked if there was a device in the company’s product line that would fend off sharks when kids were swimming around the scow. Wilson said Ocean Guardian will launch a new device for protecting the water around vessels in late winter or early spring. The device will create “at least” a 30-foot protection field, she said. She also said her company is developing an alternating-current beach barrier.
Lyon wrote that the American, Australian, and Indian navies use Ocean Guardian devices. The Times has been unable to confirm this with the Indian Navy. A spokesman for the Australian Navy emailed the following: “We purchased 86 sets of shark-deterrent devices in 2009 from SharkShield; however, the advice I have from our divers is that all shark-deterrent products we had in our inventory have been marked as obsolete. This means they have been removed from the central system as they were no longer being demanded from the diving squadrons. They also advise me that they don’t currently hold any in the squadron, so it is likely they have been removed from service.”
According to Jan Derk, an official from Naval Supply Systems Command, “[W]e did a search on vendors in the Federal Procurement Data System and it revealed no Navy contracts with SharkShield, DBA Ocean Guardian. We are checking if there were any Navy purchases outside the contract process.”
Wilson said different components of different militaries use Ocean Guardian as needed, and that the devices have NATO stock numbers for ease of ordering.
Many Vineyarders are still around who had cameos or slightly bigger roles in “Jaws.” Martha’s Vineyard Agricultural Society president Brian Athearn isn’t one of them. Because of an illness — he believes it was chicken pox — he missed playing Alex Kitner, the little boy gobbled up at the beach in front of Chief Brody.
“They wanted a little blonde-head kid, and that’s what I was,” Athearn said.
A recreational spearfisherman, Athearn has been thinking about Ocean Guardian devices, which he described as “permethrin for sharks”: “They use them in Australia. I think they work very well. I would feel completely safe using one of those things. When I have a string of fish on my hip, sharks are on my mind.”
Spearfishing is considered one of the most dangerous marine activities, shark-wise. “You’re spearfishing with a string of fish on your hip, trailing blood,” he said. “You’re basically like a lure.”
Even when not spearfishing, Athearn has concern for his silhouette. “My [expletive] in a wetsuit looks just like a seal,” he said, and added with a bit of humor, “I think we should open a restaurant that serves seal.”
The regional grey seal population has exploded in recent years. A white shark dietary delight, the marine mammals are considered a major cause of the increased shark population in Massachusetts, most notably along the outer Cape.
Longtime professional diver Heidi Raihofer downplayed the risk of a shark encounter in Vineyard waters. “We don’t really have an issue with sharks around here,” she said.
In 25 years of pro diving and instructing, Raihofer said she’s seen just three sharks: a blue, a brown, and a small thresher. Raihofer said she doesn’t even dive with a knife, and has no inclination to wear an electromagnetic defense product like Ocean Guardian. Sharks don’t concern her.“It doesn’t even cross my mind when I go in the water,” she said.
However, the issue of sharks and seals isn’t something she’s opinionless about. “I’m not for culling either sharks or seals,” she said. “Why do you want to take away their food source? Why do you want more hungry sharks?”
Amanda Wilson gave a talk at Wellfleet Elementary School Monday evening. The talk was sponsored by the Atlantic White Shark Conservancy, a Wellfleet official said. Skomal, who was present, said the talk “went very well.” Wilson was able to offer evidence to him that a “charging” white shark could be deterred by the electromagnetic field in question, he said.
“She was able to show me a paper that I was unaware of,” he said. In conjunction with the video she showed, Skomal said, “I think it was convincing.”
Skomal also said “very few” white sharks are in Massachusetts waters by December, however there can be stragglers, especially if they are in the progress of migrating from the Gulf of Maine to points south.
A recording of the event at Wellfleet Elementary School can be viewed here.