Hundreds of undocumented foreign workers are manning a fleet of Hawaii fishing vessels, often working under exploitive conditions for years at a time without a proper visa and unprotected by American labor laws, according to a new investigation by the Associated Press.

“With no legal standing on U.S. soil, the men are at the mercy of their American captains on American-flagged, American-owned vessels, catching prized swordfish and ahi tuna,” the AP investigation found. “The entire system, which contradicts other state and federal laws, operates with the blessing of high-ranking U.S. lawmakers and officials.”

Each year, the migrant workers, who hail mostly from Southeast Asian and Pacific countries, catch about $110 million worth of seafood that enter into the supply chain of restaurants and grocery stores in the U.S.

According to the AP investigation, Americans who eat Hawaiian seafood are “almost certainly” consuming fish caught by the migrant workers, who are paid as little as 70 cents an hour.

By law, 75 percent of fishermen on each commercial fishing vessel must be American. But the fleet of about 140 boats in Hawaii are almost entirely manned by the migrant workers, thanks to a loophole: an exemption pushed for by the late U.S. Sen. Daniel Inouye and other lawmakers to skirt the federal rule on the islands.

“It has the fig leaf of legality,” Cornell University law professor Stephen Yale-Loehr told the AP. “This is inconsistent with the general notion in American values, if not law, that workers should be paid a fair wage and not be mistreated.”