Anchored Fish Aggregating Devices (FADs) are overlooked and growing source of pollution in Western Mediterranean Sea

Marine litter, particularly from fishing activities, poses significant threats to marine ecosystems. In the Mediterranean, abandoned Fish Aggregating Devices (FADs) represent a widespread yet understudied form of pollution, with an estimated 1.6 million discarded over 50 years. To shed light on the extent of FAD-related impacts, this note presents results from a systematic effort in the Southern Tyrrhenian Sea, during which 1739 still-anchored FADs were recorded. The affected area was estimated at a minimum of 25,599 km², with a crude density of 0.067 FADs/km², revised to 0.215 FADs/km² after adjusting for loss rates. The study reveals an affected area over 3.5 times larger than previously reported. In addition to posing entanglement and ingestion risks to marine megafauna, the findings highlight the expanding ecological footprint of FADs and support the view that a substantial reduction in the number of deployed FADs remains the most effective strategy to mitigate their environmental impact.