Electric Signals Could Ward Off Sharks

While the menacing fin of a shark has figured in many human nightmares, people may be the stuff of shark nightmares. In addition to intentionally hunting sharks for food, fishermen often catch them inadvertently. A new plan hopes to reduce this bycatch by repelling sharks with electric fields.

Sharks have an innate ability to detect electric fields, useful for sensing the bioelectric activity of their prey. Researchers discovered that strong electric fields could repel these predators, most likely by overwhelming their electricity sensors.

"It's a sense we don’t have," said Richard Brill, a biologist at the National Oceanographic and Atmospheric Association (NOAA)'s Northeast Fisheries Science Center and head of the Cooperative Marine Education and Research Program at the Virginia Institute of Marine Science. "The closest [analogy] I can come up with is if you get exposed to a bright light, you squint and look away."

A recent test showed that small disks of a rare metal alloy called palladium neodymium interact with the salt in seawater to produce electric fields strong enough to ward off sharks. These disks could be attached to fishing lines to deter sharks from fishers aiming for other animals, thereby reducing bycatch of endangered shark species...[Live Science]