Lost tuna gear is damaging coral in marine refuges, study finds

Lost tuna fishing devices have washed into 174 protected areas across 53 maritime jurisdictions, with researchers documenting at least 6,300 strandings and finding that drifting fish aggregating devices, or dFADs, have passed through more than half of the world’s marine protected area network by total area. Published June 17 in Science Advances, the study focuses on the floating rafts industrial purse seine fleets use to find tropical tuna such as skipjack, a system that has become central to modern tuna fishing since the 1990s.

When the devices wash ashore or snag on reefs, they can smash coral, shed plastic and trap sea turtles, sharks, seabirds and other wildlife in gear that was meant to keep tuna under a buoy, not inside a refuge. The study found that dFADs have drifted through at least 37% of the global ocean, and that 1.41 million dFAD buoys were released between 2007 and 2021 to help catch nearly one-third of the world’s tuna.

Researchers identified hotspots in the central Pacific, western Indian Ocean and Caribbean. Nearly 500 at-risk species live in protected areas where dFAD strandings have already been observed. In Hawaii, large marine protected areas sit beside some of the busiest tuna grounds in the Pacific.

John Lynham, a professor at the University of Hawaii at Mānoa and a co-author of the study, said, “Marine protected areas are designed to safeguard ocean ecosystems, but drifting fishing devices do not recognize those boundaries.”

In the Galápagos Marine Reserve, local agencies and conservation groups have been tracking and removing lost FADs as gear drifts into protected water, where it can foul reefs and threaten wildlife in one of the eastern Pacific’s most closely watched tuna-adjacent fisheries. The industry has already banned netting on FADs worldwide and replaced it with ropes only in 2025.