Ratings

The Environment

The Attractive Shark Repellent

In 2002, an Australian company called Shark Shield released a brick-size transponder meant to keep away the worst fear of every diver and surfer: sharks. The thinking behind Shark Shield’s eponymous gadget is simple enough. Sharks have electroreceptors in their snouts, called ampullae of Lorenzini, that detect electric fields for navigation and predation. By emitting an irritating electric field, the idea goes, the Shark Shield would trigger a nasty sensation in the ampullae, forcing even the hungriest hammerhead to turn on its fin.