This story was produced by The Outlaw Ocean Project, a nonprofit journalism organization based in Washington. Reporting and writing was contributed by Ian Urbina, Daniel Murphy, Joe Galvin, Maya Martin, Susan Ryan, Austin Brush and Jake Conley. This reporting was partially supported by the Pulitzer Center.

Few workplaces are as gritty and brutal as distant-water fishing ships from China, and there are a lot of them: With as many as 6,500 ships, China today operates the world’s largest distant-water fishing fleet, which is more than double the size of its next competitor. It’s rarely easy for crew members to leave these ships, and often it’s forbidden.

With ships so far from shore, constantly in transit, typically operating in international waters, where national governments have limited jurisdiction, the severity and extent of forced labor in China’s seafood supply chain has long been difficult to measure. Throughout a four-year effort to document the human rights and environmental crimes associated with seafood tied to China as catch moves from bait to plate, a team of investigators at The Outlaw Ocean Project, a journalism organization in Washington, followed and, in some instances, boarded for inspection, Chinese fishing ships at sea in several locations, including in the waters close to North Korea, The Gambia, the Falkland Islands and the Galapagos Islands. When Chinese ships did not want to talk and fled the scene, the reporters followed in a skiff and threw plastic bottles with interview questions written in Indonesian, Chinese and English onto the back of the ship. In many cases, deckhands wrote answers and sent the bottles back.

The team monitored the ships by satellite back to ports, and then to pin down who was cleaning, processing and freezing the catch for eventual export, we tracked Chinese fishing ships as they moved their catch to refrigeration ships and carried it to ports in China, where the trucks from one vessel were filmed by our investigators and followed to the processing plants. And this is where we discovered that forced labor is as much a problem on land as it is far at sea.

We documented the use of Uyghur and North Korean labor to process seafood coming from Chinese ships tied to human trafficking and illegal fishing. Then we used bills of lading and other customs information, product packaging and company press releases and annual reports to track the seafood to grocery stores, restaurants and food service companies in Europe and the United States, and federal contracts databases to tie imported seafood — everything from pollock to salmon to haddock — to American and European government purchasing.

The U.S. government is among the largest institutional buyers of seafood, purchasing more than $400 million in 2022. The investigation found that a portion of this spending goes toward importers that source fish from processing plants using Uyghur labor, in violation of the Uyghur Forced Labor Prevention Act, which was passed almost unanimously in December 2021, and requires U.S. Customs and Border Protection to block the import of goods produced by Muslim Uyghurs and other ethnic minorities from Xinjiang province. The Chinese government has systematically subjected these groups in recent years to forced labor programs at factories across the country monitored by uniformed guards, in dorms surrounded by barbed wire. (The Chinese Foreign Ministry declined to answer questions about the use of Uyghur and forced labor in seafood processing plants. But in response to the passage of the Uyghur Forced Labor Prevention Act, the ministry released a statement that called the allegations of forced labor, “nothing but vicious lies concocted by anti-China forces.”)

Since 2022, Customs and Border Protection has detained more than a billion dollars of these goods, especially tied to industries like cotton, solar panels and tomatoes that were previously known to be heavily worked by Uyghurs. Seafood imports have largely slipped oversight, however, partly because the plants relying on these workers are located far from Xinjiang, a western area of the country that is among the farthest from the sea of anywhere on the planet. The Chinese government has instead forcibly relocated tens of thousands of these workers, loading them onto trains, planes and buses, and sending some to seafood processing plants in Shandong province, a fishing hub on the eastern coast. These findings were based on Outlaw Ocean Project reporting conducted using cell phone footage from factories and other places in China posted to social media, seafood company newsletters that mention meetings with government officials about solving labor shortages, state media reports, more than three dozen worker testimonies and direct surveillance of some plants. (For more detailed sourcing, see Outlaw Ocean Project’s website.)

The investigation found that more than $50 million worth of salmon was supplied to federally funded soup kitchens and programs to feed low-income elders by importers that source from plants using Uyghur labor. This wasn’t the only species produced by forced labor that ended up on plates in the U.S. Over $20 million worth of pollock, mostly as fish sticks, was shipped to the National School Lunch Program and other federal food assistance programs. The National School Lunch Program feeds kids in over 100,000 public schools in the country. More than $140 million worth of cod, salmon and halibut was delivered to commissaries and cafeterias at hundreds of U.S. military bases domestically and abroad. Thousands of dollars’ worth of fish patties went to federal inmates in Wisconsin. The U.S. government even donated over $300,000 worth of canned pink salmon to Ukraine to support the war effort, some of it supplied by an American company named OBI Seafoods, which, the investigation found, sources from a Chinese plant using Uyghurs. (OBI Seafoods did not respond to requests for comment.)

By email, Rep. James McGovern (D-Mass.), a member of the Congressional Executive Commission on China, which monitors human rights in the country, said he was proud that the Uyghur law was being robustly enforced by Customs and Border Protection, including the recent addition of 24 companies that use forced labor to the restricted list. He added, in response to the findings of this investigation: “I hope that any and all allegations of forced labor, especially for products purchased by American taxpayers, are taken seriously and investigated thoroughly.”

In separate reports over the past two years, the U.S. State Department and the National Oceanic and Atmospheric Administration named China in a list of countries most likely to engage in illegal labor practices in the seafood sector — forced labor through debt bondage, wage withholding, excessive working hours, beatings of deckhands and passport confiscation, as well as abandoning crew in port and general neglect. In one case, we received a video from Filipino deckhands who had filmed aboard a Chinese vessel where they said they were being held captive. “Please rescue us,” one of the deckhands on the Han Rong 368 pleaded in a July 2020 video, recorded on his cell phone from the Indian Ocean, near Sri Lanka. “We need to go to the hospital,” he said. “Please, we are already sick here. The captain won’t send us to the hospital.” (The agency that placed these workers on the ship, PT Puncak Jaya Samudra, did not respond to requests for comment.)

The Department of Defense, which runs military bases, and the Department of Justice which runs the Federal Bureau of Prisons, declined to comment about the purchase of seafood from American importers tied to processing plants in China using Xinjiang labor. Allan Rodriguez, a spokesperson for the USDA, which oversees the National School Lunch Program, said: “USDA requires that our seafood products be sourced in U.S. waters by U.S. flagged vessels and produced in U.S. establishments approved by the U.S. Department of Commerce’s Seafood Inspection Program.”

The U.S. government is by no means the only buyer of seafood coming from these ships and the processing facilities in violation of the import ban. The investigation found more than 6,000 tons of seafood coming from the plants since June 2022 went to U.S. restaurant chains, grocery stores and food service companies including Walmart, Costco, Kroger and Sysco.

In response to questions about these concerns, a spokesperson for Walmart said the company “expects all our suppliers to comply with our standards and contractual obligations, including those relating to human rights.” A spokesperson for Sysco said that their supplier, Yantai Sanko Fisheries, had undergone audits and had reassured them that it had never “received any workers under a state-imposed labor transfer program.” Costco and Kroger did not respond to requests for comment.

The investigation also found seafood from these plants going to companies in the EU, Australia, South America and the Middle East. But the revelation that even the U.S. government is buying goods tainted by Chinese forced labor is striking since such purchases, paid for by taxpayer dollars, are supposed to face higher scrutiny.

This lapse highlights the murky nature of the world’s seafood supply chains and has spurred calls from American lawmakers, ocean conservationists, consumer advocates and human rights organizations to require U.S. importers to track their seafood from bait to plate to ensure it is not tied to labor and environmental crimes or violates sanctions on “pariah” states like North Korea and Iran. In the many handoffs of catch between fishing boats, carrier ships, processing plants and exporters, there are gaping holes in traceability.

In 2022, the Biden administration was confronted by the difficulty of tracing this supply chain after it issued an executive order prohibiting the import of Russian seafood. The effort was aimed at depriving Russia of billions of dollars that might go toward the war in Ukraine. But members of Congress soon pushed back, saying that the ban was largely unenforceable. During a hearing on the import ban in April 2022, Democratic Rep. Jared Huffman from California said that until the U.S. closes loopholes in their oversight of this supply chain, “Russian seafood will continue to line grocery store shelves, and American consumers will continue to unwittingly support Putin’s war machine.”

American lawmakers say that China’s dependence on illegal practices puts domestic fishermen at a competitive disadvantage. (The Chinese Ministry of Foreign Affairs declined to comment on this allegation.) “We cannot continue to allow countries such as China and Russia to undercut our honest fishers by abusing our oceans and fellow human beings,” said a June 2022 letter to Biden signed by Huffman and Republican Rep.