Scientists are still not really sure if, or how, magnetic shark repellents work.
Sharks get a bad rap, though sometimes for good reason. At times they can be a nuisance, or even a threat. They eat endangered seals; occasionally take a bite out of unsuspecting swimmers and surfers; and, to their own detriment, get caught in gear intended for other fish. Technology that would allow people to repel hungry sharks might save countless lives—particularly the sharks’. Read more in Hakai.