Aquaculture’s dirty secret: The dark side of the seafood you eat

Some fishmeal is made from the heads, guts and other remains of wild-caught fish that are processed for human consumption.

At any given time, there are many fishing boats operating illegally and taking steps to avoid detection by regulators. Scientific research classifies at least half of the species caught by these vessels as "overexploited" or in danger of disappearing. The global fishmeal industry's fishing fleet consists of hundreds of bottom trawlers, which use heavily loaded nets to scrape the seafloor, destroying nearly everything in their path.

From the South China Sea to the far reaches of the North Atlantic, our reporters board fishing boats harvesting ingredients for the fishmeal industry. We reviewed logbooks, interviewed workers, and documented illegal operations. The investigation found that hundreds of fishmeal raw material fishing vessels were operating in prohibited or protected waters, violating fishing quotas for specific fish species, or fishing without licenses.

Working conditions on some fishing boats are extremely harsh. Some deck workers said their passports were confiscated, they were forced to work 15 hours a day and were beaten by senior crew members. On Chinese and Russian fishing vessels, we have uncovered instances of worker injuries and forced labor, including debt bondage and cases where requests to leave the vessels were blocked. On a Chinese fishing vessel operating off the coast of West Africa, the crew either sleeps on the deck, exposed to waves and rain, or is crammed into exhaust-filled, stuffy, cramped and dangerous cabins.

Since 2019, more than a dozen people have died while working in Peru’s fishmeal industry. Peru is the world's largest fishmeal producer, typically supplying more than a fifth of the world's fishmeal. Workers on the country's fishing vessels are sometimes knocked unconscious by toxic gases released from hundreds of tons of rotting fish in fish holds. In 2023, two men fell into the cabin while unloading anchovies for Copeinca, a large Peruvian fishing company, and died of suffocation. (CFG Investments, which owned Copeinca at the time of the accident, did not respond to a request for comment. The company's current owner, the Canadian company Cook, said the responsibility for the accident did not lie with Copeinca but with the fishermen themselves.)

Some workers fell into the sea or were hit by heavy equipment and died. Also in 2023, a fisherman from another Peruvian company, TASA, was hit and killed by a cable at sea. A spokesman for the company said that after the accident, TASA "mobilized all necessary human and logistical resources" to respond to the accident and provide care for those affected by the death, including providing psychological support to the family of the deceased.

Workers are far from the only ones affected. The fishmeal industry has destroyed the food security and livelihoods of coastal communities over the past decade.

A fleet of brightly colored wooden canoes has fished West Africa's coastal waters for generations, supporting a thriving industry of dockworkers, traders and shippers, as well as thousands of women who smoke, dry and sell fish in local markets. But now, dozens of fishmeal ships plunder these waters, sending their catch to dozens of fishmeal factories in Mauritania, Senegal and The Gambia.

Although new regulations limit fishing intensity, Mauritania remains particularly attractive because its waters are exceptionally rich in marine life thanks to the strong nutrient upwelling produced along the coast by the Canary Ocean Current. There, Chinese and Turkish vessels fish for West African pilchards, pilchards and small round and flat sardines - known as forage fish, which sit at the bottom of the food chain and are eaten by other marine life or seabirds.

They are also eaten by humans. These fish are vital to the food security of millions of people in West Africa; sardines may be small but provide significant amounts of important nutrients and are one of the cheapest and most important sources of animal protein in the region. Since the fishmeal industry expanded into West Africa, round-bodied sardine populations have fallen to their lowest levels on record. Today, three of these four fish species are classified as overexploited by the United Nations.

It turns out that much of the damage caused by foreign fishmeal ships off the coast of West Africa remains undetected. Vessels turn off their transponders, or fake their bearings through "location spoofing" to evade any effective surveillance by local authorities. The practice is particularly common off the coast of Mauritania: at least 21 foreign fishing vessels operating there camouflaged their locations between 2019 and 2025, according to satellite data. There are also many vessels that frequently perform transshipments, which involves transferring fish to refrigerated vessels rather than returning to port. The banned practice circumvents local taxes, quotas and protected species regulations. It would be easier for fishing vessels to evade this rule if they disappeared from satellite tracking.

The Mauritanian government has had mixed reviews for its regulatory oversight of its fish stocks and the livelihoods they support. Mauritania ranks among the top African countries in a 2025 World Bank assessment of preventing industrial vessels from entering protected areas, but watchdogs say the government still struggles to determine who is fishing, how much is being caught, and whether regulators have been enforcing rules against vessels at sea.

On at least one occasion, the Mauritanian government appeared to be trying to suppress the problem of illegal fishing. On July 22, 2025, Ali Bakar, an environmental activist in the country, posted on Facebook that a Turkish fishmeal ship had faked its location while operating in the Bondarkin National Park off the coast of Mauritania. "It is likely to be involved in illegal fishing," Bakar wrote. That same day, police showed up at his home and arrested him.

Accused of "publishing misleading information" on the Internet, he was imprisoned, had his head shaved and placed in a rat- and cockroach-infested cell with more than two dozen people. Unwilling to sign a letter of apology to the coast guard and fishing agencies, he was held for about two months before being released under pressure from international rights groups.

Like Mauritania, Senegal appears less willing to put the interests of its own people ahead of foreign investment. In 2024, the European Union issued a "yellow card" warning to the country, saying that it had not fully cooperated in combating illegal, unreported, and unregulated fishing.

The United Nations says plundering of these already overexploited fish stocks is a major driver of migration. Thousands of Senegalese fishermen have lost their jobs, prompting many to flee the country by boat. They typically attempt to sail nearly 1,000 miles from Senegal to the nearest European landing point, Spain's Canary Islands.

The migration route from West Africa to the Canary Islands has claimed thousands of lives. In September 2024, a fishing boat carrying about 100 migrants to Spain capsized, killing more than 20 people. One of the survivors, 21-year-old Sheku Omar, swam for 10 hours holding on to the wreckage to reach the shore. He explained to our reporter how the fishmeal industry influenced his decision to immigrate. “We are fishermen,” he told them, “but there are no fish here anymore.