Tuna love to congregate around objects adrift at sea, so industrial fishing vessels release thousands of man-made plastic-heavy fish aggregating devices (FADs) into the sea every year to round up the tuna.In the Indian Ocean, the European-dominated purse seine tuna fishery relies heavily on FADs and is largely responsible for the waste that collects on remote biodiversity hotspots like Seychelles’ Aldabra atoll, experts say.FADs are also partly responsible for pushing the Indian Ocean yellowfin tuna stock to the brink of collapse, but efforts to move away from harmful FADs lack urgency.This is the second story in a two-part series about the effect European tuna fishing has on the economy and marine environment of Seychelles, an archipelagic nation in the Indian Ocean. In 2019, when Jeremy Raguain turned up for a cleanup campaign on Aldabra Atoll, a UNESCO World Heritage Site, he bagged a marine monstrosity like no other: a beached fish aggregating device, or FAD. It was a massive tangle of buoys, netting and fishing ropes weighing hundreds of kilograms. The fishing aid, like most FADs, was made of a floating raft and an underwater trail. More than 80% of the plastic garbage washed up on the Indian Ocean atoll, home to Seychelles’ iconic giant tortoises, is fishing-related, Raguain, a Seychellois marine conservationist, and his team estimated. Vessels from Spain and France have for decades exploited Seychelles’ abundant tuna stock and left waste behind in its waters. “It’s not to say that they’re the sole culprits. But they are by far the largest,” said Raguain, who co-led the cleanup effort on Aldabra. Purse seine tuna-fishing vessels release thousands of FADs into the seas every year, abandoning many of them there. When forsaken FADs drift ashore, it falls on volunteers and environmentalists like Raguain to clean up after industrial fishing fleets. He and five team members spent an entire day under the scorching Seychellois sun dismantling that one monster FAD.