It’s difficult to fathom the deplorable conditions foreign workers often endure on American-owned fishing vessels that dock in Honolulu. Trapped on boats without visas, many laborers live in squalor, receive inadequate medical care and are paid as little as 70 cents an hour.

Even more discouraging is that their treatment, under current laws and rules, is legal. So it’s critical that those who can effect change work quickly to close longstanding federal loopholes that allow what amounts to slave labor in Hawaii waters — the result of which is “locally sourced” swordfish and tuna that end up in res- taurants and markets across the state and mainland.

It would seem implausible that, in this day and age, about 700 undocumented men working on a fleet of about 140 boats lack rights most Americans take for granted. But their plight was revealed in an Associated Press expose published Thursday in the Star-Advertiser, highlighting the need for strong reform.

The AP reported that by law, U.S. citizens must make up 75 percent of the crew on most commercial fishing vessels in America. However, influential lawmakers, including the late U.S. Sen. Daniel Inouye, pushed for a loophole to support one of the state’s biggest industries.

That loophole exempts commercial fishing boat owners from federal rules enforced almost everywhere else — and it legitimizes abhorrent labor and wage practices that the U.S. would not condone in other parts of the world. As U.S. citizens and Hawaii residents, we should be appalled that American- owned businesses are exploiting undocumented workers — even if current laws allow it.

The fishermen, mostly from impoverished Southeast Asian and Pacific island nations, sign long-term contracts and work under grueling conditions — sometimes 20 hours a day. Because they have no visas, they are not allowed to set foot on Hawaii’s shore.

Lawmakers must right the ship over treatment of undocumented workers within the country’s fifth top-grossing fishery. U.S. Sen. Mazie Hirono has proposed an amendment — unsuccessful so far — that would allow workers to fly into the country rather than enter illegally.

But the reforms will need to go deeper than that, though no doubt there will be strong pushback from the industry.

State Rep. Kaniela Ing, after reading the AP report, has asked state Attorney General Douglas Chin to investigate whether vessels that operate largely from Honolulu might violate Hawaii labor and business laws. Ing, chairman of the state House Ocean, Marine Resources and Hawaiian Affairs Committee, asks Chin in a letter whether the reported acts “constitute a restraint of trade or other anti-competitive practices prohibited by (Hawaii law).”

While the fishing vessels operate in federal waters in accordance with federal law, Ing said he believes the vessel operators are licensed to do business by the state of Hawaii. “We can all agree that any abuse of any human being has no place in our Aloha State,” Ing said. “These investigations reveal why we must act now.”

Whether Ing’s letter will move the needle on the issue remains to be seen — though we urge Chin to make the matter a priority.

“I received Representative Ing’s letter inquiring about the actions of fishing vessel operators at Honolulu Harbor Piers 17 and 38. This office is reviewing the questions posed by the Representative,” Chin said via email. “We will respond to him as appropriate.”

In the meantime, while front-end improvements must be made through changes in laws and rules — and perhaps through investigation by the state — on the back end, buyers of local seafood need to educate themselves on how prized fish is sourced.

Consumers must decide whether they should support an industry built on the backs of underpaid and overworked foreign fishermen whose catch ends up at restaurants and seafood counters nationwide. Their catch fetches a premium, but undocumented fishermen reap little of the benefits — and those abusive conditions must change.

In the AP story, Sorihin, a fisherman who uses one name, described how a fishing line nearly ripped his finger off, and his captain set it straight with a chopstick. Conditions were so bad that he and another fisherman escaped their boat one morning while docked in San Francisco.

Sorihin told AP that American seafood consumers should ask where the fish came from: “Is it the kind of fish that you got from someone in slavery?”

Bold reform is what’s needed to shore up a broken system that exploits undocumented workers on American-owned vessels. The U.S. must work to close loopholes in federal law that allow Hawaii’s fishing industry to skirt labor and wage laws that should protect workers — whether foreign or domestic.