AP’s Martha Mendoza, an investigative reporter based in Bangkok, and Margie Mason, medical writer in Jakarta, found that hundreds of undocumented men, many from impoverished Southeast Asian and Pacific nations, work in this U.S. fishing fleet. They have no visas and aren't protected by basic labor laws because of a loophole passed by Congress.

A story detailing the men’s plight, by Mendoza and Mason, resulted from a tip following their award-winning Seafood from Slaves investigation last year. It earns the Beat of the Week.

In this latest investigation, in which a multi-format team reported in San Francisco, Hawaii and Indonesia, Mendoza and Mason discovered these workers are at the mercy of American captains on American-owned ships. One official likened the boats to “floating prisons.” The fishermen's catch includes high-end seafood (a single yellowfin tuna can fetch more than $1,000) touted by celebrity chefs and sold in stores including Whole Foods and Costco.

The story's stark conclusion: If you eat Hawaiian seafood, it is almost certainly caught by one of these 700 workers. They catch about $110 million worth of seafood annually.

If you eat Hawaiian seafood, it is almost certainly caught by one of these 700 workers

The fleet includes about 140 boats that dock along the West Coast, mainly at Piers 17 and 38 in Honolulu, but also Fisherman's Wharf in San Francisco. The AP reporters interviewed more than 50 fishermen, some of whom lived in squalid conditions without toilets. One worker was sent home to Indonesia after nearly dying when his boat sank off Hawaii. He lost everything and it took four months for him to get paid.

The investigation stemmed from a tip Mendoza received while she and others were still working on the Southeast Asia slave fish investigation. While she was attending a seafood conference in San Francisco, a fisherwoman approached her, saying: "Why are you worrying about men in Indonesia? You should come down to Fisherman's Wharf. There is something wrong on some of these boats."

Mendoza contacted Mason and international enterprise editor Mary Rajkumar, reporting that local fishermen agreed something was amiss. “When they come in to port, the crew is not allowed off the boat _ if they do get off the boat, the captain calls Immigration and the crew member is arrested."

The next time a boat called the Sea Queen II docked in San Francisco, Mendoza got word from the woman and headed out, joined by San Francisco-based photographer Eric Risberg. When a passing boat drifted and accidentally bumped the Sea Queen II, the entire crew ran out on deck, and Risberg had his chance to shoot up-close photos.

Mason did some initial work on the investigation in Hawaii while on vacation in December, and Mendoza continued digging on the California side. In February, they traveled to Honolulu with videographer Haven Daley. Honolulu-based correspondent Caleb Jones began working as a photographer on the project.

The work was split up. Mendoza and the others did ride-alongs with the Coast Guard, Customs and Border Protection agents. Mendoza also talked with buyers at fish auctions to find out where the seafood goes on the mainland. Mason talked with fishermen, brokers and other sources at the piers. Every evening, they compared notes.

Mendoza explored the legal loophole, which was complicated and nuanced, allowing the foreign crewmembers to work but exempting them from most basic labor protections. She found a concrete connection to the late Sen. Daniel Inouye of Hawaii, whom she’d been told was the one who created the system.

After interviews by Mason in Honolulu helped locate fishermen from an Indonesian village, an all-formats team traveled there from Jakarta: Mason, photographer Dita Alangkara, videographer Fadlan Syam and reporter Nini Karmini. Many fishermen were from Pemalang, on Java's central coast. Since these men were home, they could speak freely on video, allowing the AP to use their names.

In California, Mendoza tracked down two former fishermen who had fled from their boats and found help, ending up with special visas designated for victims of human trafficking. They were willing to talk but didn't want their faces shown; photographer Jeff Chiu and Daley captured images accordingly.

The cross-format package, edited by Rajkumar and Kristin Gazlay, Top Stories desk editor at large, won tremendous play:

http://apne.ws/2c0FQ6s Jones coordinated the photos and Daley did the video. The story, reaching No. 1 on AP Mobile, ran on the front page of the Honolulu Star-Advertiser and three pages inside. The paper later editorialized, calling for changes. Alaska's Ketchikan Daily News ran an editorial titled, "Well done, AP," calling it "conscientious, thorough reporting." NPR’s "All Things Considered" interviewed Mendoza.

Whole Foods announced it would no longer buy fish from Honolulu's auction. State Rep. Kaniela Ing in Hawaii contacted the state's attorney general and asked for an investigation; he has promised he will work to stop the practices, proposing new legislation if necessary. Some Capitol Hill staffers also asked for details, saying their offices would try to work on changes.

John Hocevar of Greenpeace said: "I think this will help catalyze some real change, and well beyond Hawaii."

For their startling findings on these abusive but legal conditions, Mendoza and Mason earn this week's $500 prize.