ADELAIDE, Australia (29 Mar 2002) -- Australia-based SeaChange Technology has launched a compact, light-weight electronic shark repellent, the next best thing to a ban on shark feeding. Now you can enjoy diving and snorkeling with less fear of shark attack provided you're willing to shell out US$400 for a Shark Shield unit. Sound too good to be true? According to SeaChange Chairman, Rod Hartly, the units were 100% successful over thousands of field tests. "Sharks are often near seal colonies, so we'd go to a seal colony and get a huge bloody piece of meat like a horse's leg, strap it to a surfboard, then pour blood in the water and watch what happened," Hartly said. "Five thousand times we tried this, and 5,000 times the sharks pulled away." Marine biologist and shark expert, Ian Gordon, who was one of the Shark Shield "test pilots", says that sharks turn away when they get within 4 or 5 meters of a diver. "All life forms give off an electric current - what we'd call an aura - and the Shark Shield's aura irritates sharks," said Gordon. "I'd be in the water and when the sharks came in to attack they'd hit the electrical current and turn away." While less than 100 people are attacked by sharks each year, commercial fishers kill about 100 million sharks annually and many species are now threatened or endangered. Gordon also considers Shark Shield an eco-friendly improvement over shark nets, which often kill sharks. "Anything which can repel sharks but doesn't actually kill them or hurt them is a step in the right direction," Gordon explained. | | How Shark Shields work The shields are about the size of a paperback book and can be strapped to the ankle or leg. The battery-powered Shark Shield generates an electrical field that, it is believed, is detected by the shark through its sensory receptors, known as the Ampullae of Lorenzini, found on the snouts of all predator sharks. Once detected by the sharks' sensors, the field causes muscular spasms that result in the shark being repelled from the area. The field is projected from the unit by two electrodes, which create an elliptical field that surrounds the user. Currently, two units are being manufactured including a surfing model that weighs about 450 grams (one pound), and a diving model that weighs about 950 grams (two pounds). Rechargeable batteries account for the difference in weight and battery run time. The surfing unit battery lasts for two hours, while the diving unit battery lasts for four. Shark Shields will be sold in dive centers, surf shops and sporting goods stores. © CDNN - CYBER DIVER NEWS NETWORK |
