Fish Aggregating Device (FAD)

A fish aggregating device is a floating structure, anchored or drifting, that pelagic species such as tuna gather around for reasons not fully understood (hypothesized to include shelter, visual orientation cues, and the invertebrate communities that colonize the structure itself), making it one of the most effective and most criticized tools in industrial tuna fishing. Drifting FADs, often simple bamboo-and-netting rafts fitted with a satellite buoy for tracking, are deployed by the thousands across ocean basins and let purse-seine vessels locate and set on tuna schools without visual scouting, dramatically increasing catch efficiency but also increasing bycatch of juvenile tuna and non-target species compared to free-school sets. A significant fraction of deployed FADs are never recovered and drift until they ground on reefs or coastlines as ghost gear, entangling marine life and damaging coral, which has pushed regional fisheries bodies toward mandatory non-entangling and increasingly biodegradable FAD designs plus FAD-limit quotas per vessel. For traceability purposes, FAD-associated catch is now routinely disclosed on product labels as a distinct category from free-school catch, since the two carry materially different bycatch and ecological footprints.