‘The sea is like a minefield’: The web of illegal fish traps in Italy’s Mediterranean

Off the coast of Sicily, Sea Shepherd and its volunteers are hunting down illegal fish traps and working with Italian authorities to crack down on this environmental crime.

The flat water melts into the teal-coloured sky as a former pilot vessel, the Sea Eagle, sails through the calm Tyrrhenian Sea surrounding the Aeolian Archipelago of Sicily.

The ship is operated by Sea Shepherd, an international marine conservation non-profit. Today, the team is searching for fish aggregating devices (FADs), man-made plastic structures used to attract fish. They float in the water, anchored to the seafloor, with hanging nets to catch fish. FADs made from plastic, without GPS tracking devices attached, are illegal in Italy.

While listening to techno music, a group of volunteers uses a winch to detach one of the FADs from the seafloor. A large plastic container labelled “corrosive” emerges from the sea.

“The [techno] rhythm gives us the right energy,” says James* (the crew do not wish to use their full names for safety reasons), a young Canadian volunteer who is running the operation and whose arms are covered in ocean-inspired tattoos. The volunteers work tirelessly to extract the plastic FADs from the sea and pile the tangled trash heaps into big bags. The retrieved plastic will be turned into plastic crates for sea turtle rescue operations.

FADs are used worldwide by fishermen to attract pelagic fishes into surrounding nets. These fish-trapping devices are typically composed of used fuel, pharmaceutical and other chemical containers among other types of plastic waste, dark plastic nets and rocks, all of which is held together by a few miles of nylon thread. Marine wildlife is attracted to the shade provided by FADs.     

Abandoned FADs are illegal. They can cause a wide range of adverse environmental impacts, including the entanglement of marine life (particularly sharks and turtles), act as a habitat for the spread of invasive species, and wash ashore on beaches or become stranded on coral reefs. Many lost or abandoned FADs sink, causing environmental harm to deep-sea habitats.

The material the FADs are made of matters too. FADs are required by Italian law to be biodegradable. All the FADs removed by the Sea Shepherds from the South Tyrrhenian Sea are illegal and made of plastic, says Nicola Silvestri, frigate captain and head of the Fishing Control Centre area in Western Sicily. They also lack markings which allow them to be traced back to the fishing boat that used them, he says.

“Illegal FADs are very cheap to produce, but at the same time highly dangerous for ecosystems,” says Andrea Morello, president of Sea Shepherd Italy. “These devices are installed by fishers in the month of August, then they catch fish around them in summer. Eventually, winter storms remove the devices, creating tonnes of hazardous and plastic waste floating in the sea.”

In this stretch of sea around Sicily’s Aeolian Archipelago, the target fishing species in the summer are juvenile ricciola, bluefin tuna, juvenile swordfish and pilot fish. FADs can damage the entire population, by preventing juveniles from maturing and reproducing.

The Sea Shepherd mission is part of the organisation’s ongoing Siso operation in Sicily to combat these illegal fishing devices.

“We are witnessing the biggest marine environmental disaster ever,” says Morello. “The sea is like a minefield full of FAD lines in every direction, placed by fishers who split the sea surface among them, threatening biodiversity.”

The Sea Shepherd volunteers remove the long nylon threads attached to the FADs which can harm fish, turtles, humpback whales and dolphins by trapping and suffocating them. According to Sea Shepherd, there are more than 36,000 FADs, each one composed of almost 1.2 km (0.7 miles) of nylon lines in the South Tyrrhenian Sea, part of the Mediterranean Sea.

It takes the volunteers one hour to extract almost 2km (1.2 miles) of a FAD line, it’s the first out of seven removed that day. Not far away, a police coast guard boat is monitoring the work: later it will seize the illegal plastic materials. The use of FADs made from plastic waste, without GPS trackers, is an environmental crime in Italy.

Sarah, a young German volunteer, rings the bell installed on the deck of the vessel, to celebrate and notify the crew that another FAD has successfully been extracted from the seabed. In total, the volunteers haul seven FADs onto the deck that day – their combined mass is the same size as a small car.

Sea Shepherd runs covert missions, so that they are undetected by illegal fishers. The organisation maps the FADs using deep-sea radar technology and binoculars and removes them in collaboration with national maritime authorities.

Between 2017 and 2024, the organisation removed 676 FADs from the Mediterranean Sea, says Morello. “We define ourselves as FAD hunters: here to protect the sea. We are also carrying out the first census of FADs ever realised in the Mediterranean Sea,” he says.

The data collected during this mission will be analysed as part of a research project that Sea Shepherd runs with the National Biodiversity Future Centre of the University of Palermo in Sicily and the Cima Research Foundation, based in Liguria, Italy. Using statistical analysis, Sea Shepherd has been producing maps since 2017 to identify for the first time the extent of this ghost labyrinth created by FADs anchored to the seabed.