The solution to preventing thousands of sharks per year from getting snared on fishermen’s hooks and dying could be magnets.

Michael Herrmann, a research associate at the U.S. organization Shark Defense, won the International Smart Gear Competition, a contest sponsored by the World Wildlife Fund (WWF) that invites people from around the world to design fishing gear to reduce the problem of “bycatch,” or fish and mammals accidentally getting caught by fishermen, according to a statement from WWF Costa Rica.

The problem of bycatch has pushed some shark species to the brink of extinction, with some populations down by 90%.

Recognizing that sharks can detect magnetic fields, Herrmann discovered that placing strong magnets just above fishermen’s hooks on long lines can repel certain species.

As the winner of the contest, Herrmann was awarded $25,000 to put the idea into practice, said WWW spokeswoman Cinthya Flores.

“He’s already proved that the magnets work, and now he can make them available for other people to use,” Flores said.

Asian Pacific waters have the highest incidence of bycatch, which affects seabirds, mammals, sea turtles, tuna, sharks and other fish, Flores said, while in Latin America, it occurs the most in Ecuador, Colombia, Panama, Costa Rica and Mexico.

In this year’s Smart Gear Competition, WWF received more than 80 entries from 26 countries around the world. The entries were judged by an international panel composed of gear technologists, fishery experts, representatives from the seafood industry, fishermen, scientists, researchers and conservationists.

Through the Smart Gear Competition, WWF seeks to find, reward and promote inexpensive tools for fishermen to reduce the problem of bycatch, the statement said.