Our oceans are full of sophisticated, perfect traps: Nets, hooks, fishing lines. Designed to capture animals destined for our dinner tables, they often catch other wildlife too.

This accidental harvest is known as bycatch, and every year it causes the death of millions of marine animals, including whales, dolphins, sharks, turtles, and seabirds. Nets and gear can asphyxiate animals or cause fatal injuries; even when the animals are tossed back to sea, they frequently die. Bycatch is also a dilemma for fishermen—entangled creatures can destroy equipment, costing time, money, and fisheries’ reputations.

Over the decades, conservationists, researchers, and fishermen have developed ways to minimize various kinds of bycatch in different fishing stocks around the world. But putting these solutions to work is often a challenge, and many mitigation strategies are never widely implemented.

Some approaches, however, now have a proven success rate—and more may be on the horizon. Recent research has explored nets equipped with lights; even low-tech tricks like kitting out gear with plastic water bottles show promise of reducing some kinds of bycatch while also being practical for fishermen to use.

Despite the challenges, researchers are hopeful. “There are not very many conservation issues that I’m aware of where industry and conservationists and consumers and the fishermen and the resource users all want the same thing,” says marine biologist Matthew Savoca, a research scientist at Stanford University’s Hopkins Marine Station. “Every stakeholder wants less bycatch.”

Keeping turtles out

The bycatch problem has always existed. “It’s a conflict that’s intrinsic to the whole idea of fishing,” says marine scientist Nancy Knowlton, marine biologist emerita at the Smithsonian’s National Museum of Natural History. “If you have something that’s designed to catch animals, you’re going to wind up, almost always, catching some things that you didn’t mean to catch.”