Countless sharks, sea turtles, seals, dolphins, rays and fish of all descriptions needlessly die before they can be thrown back overboard. Philippe Colombi/Getty ImagesWe kill 100 million sharks every year. We found that traps with magnets had roughly 30 percent less likelihood of catching sharks and rays compared to traps without. Win-wins are great, but we've got a long way to go before we make a dent in that 100 million sharks per year. The magnets seem to work well for traps, but magnets don't work on longlines — the lines are fitted with metal hooks, so the magnets tangle the gear.