The U.S. Coast Guard is raising new safety concerns for crews that harvest tuna from some of the most remote waters in the Pacific following a spate of accidents in the past eight years that have left 19 crew members dead aboard commercial tuna vessels flying U.S. flags.

The service this week announced fines against the South Pacific Tuna Corp., a U.S.- and Taiwanese-owned company that operates 14 of the 40 large industrial tuna vessels that compose what’s called the "distant-water tuna fleet," which operates in foreign Pacific waters under international treaty.

The distant-water tuna fleet is different from the longliner fleet based in Honolulu, which the Coast Guard described as a much safer operation.

The fines stem from 2012 inspections that found the company had repeatedly used unlicensed foreign nationals to illegally serve as engineers and chief mates on five of its boats, instead of the licensed foreign workers pre-vetted by the Coast Guard.

"We found that other people were filling those positions that hadn’t been approved," Honolulu-based Coast Guard Capt. Chris Woodley said Tuesday. In some cases those approved were on board but were doing other jobs. In other instances they weren’t aboard at all, Woodley said.

Coast Guard officials called the incidents worrisome because those jobs are key to safety aboard the distant tuna boats. Since 2006, workers in the U.S. distant tuna fleet have died falling overboard, in helicopter crashes, succumbing to "confined-space gasses" even being struck by a 110-pound tuna falling from vessel nets, according to Coast Guard reports to Congress.

"This fleet has a safety problem," Woodley said. "This is not your mom-and-pop fishing operation. It’s a very complex, dangerous operation, and so one of the key things is manning. You need to have safe boats and good people to operate your boats."

Despite being U.S.-flagged boats, many of the distant-water fleet "purse seiner" vessels, which typically have crews of 30 to 35 people, have only one American aboard: the ship’s captain. That practice is entirely legal. South Pacific Tuna Corp. officials say they need special legal exemptions that allow all but one crew member to be foreign nationals in order to stay competitive in the global tuna industry.

"Once everyone else got into the picture, there was no way that the U.S. could compete, labor-wise, with the rest of the world," South Pacific Tuna Vice President of Operations Bobby Virissimo said Wednesday. "No one (from the U.S.) is going to go aboard these boats to make $10,000 a year. We just can’t get the people to come on the boats."

South Pacific Tuna’s U.S.-flagged vessels were built in Taiwan and are about 51 percent American-owned and 49 percent Taiwanese-owned, company officials said.

The tuna that those ships harvest is canned, and it’s brought to Thailand, China, Fiji, Ecuador and other countries for processing, company principal J. Douglas Hines said. Some of it eventually makes it to U.S. shores, he added.

Since 2006 the fleet of 40 or so boats, which includes the South Pacific Tuna vessels, has hauled in a tuna catch valued at more than $2.1 billion, according to the Pacific Islands Forum Fisheries Agency.

At least seven of the 19 distant-water tuna fleet deaths since 2006 occurred on South Pacific Tuna boats, according to Coast Guard annual reports.

In a Thursday news release responding to the safety concerns, the company said the 2012 violations stemmed from safety documents that expired when the vessels’ annual inspections in port were delayed.

"Despite the expired documents, the foreign officers on board were licensed and had been approved," the release stated. However, in a Wednesday phone interview, South Pacific Tuna officials acknowledged that in at least one of the instances, the licensed crew members approved by the Coast Guard were not on board.

Furthermore, the South Pacific Tuna statement touted a record of "zero fatalities" in 2013 but Coast Guard records indicate that’s not the case.

The agency reports that the company’s Pacific Ranger purse seiner was involved in a helicopter crash in 2013 that left one person dead. Also, in 2014 a 25-year-old man died aboard the Pacific Ranger from injuries when he fell into a fish hold, according to Coast Guard Chief Petty Officer Kurt Fredrickson.

Both incidents remain under investigation, Fredrickson said in an email.

Even with the scrutiny of the U.S. distant-water tuna fleet, commercial fishing overall remains a hazardous job around the country with myriad fatalities from injuries, plunges overboard and vessel sinkings and crashes.

Virissimo and South Pacific Tuna officials Wednesday pointed to 500 commercial fishing deaths in Alaska, the Gulf of Mexico and the western and eastern mainland U.S. coasts from 2000 to 2009.

But those fishing deaths, compiled by the National Institute for Occupational Safety and Health, involve thousands of vessels, versus a fleet of 40 ships. In Alaska alone there were some 8,600 commercial fishing boats operating in 2011, according to a recent economic report on that state.

After the distant-water tuna fleet suffered five deaths in 2012, the Coast Guard told Congress in its annual report that the fleet’s fatality rate was four times as bad as the national rate.

The Coast Guard’s fines for the South Pacific Tuna violations, however, amount to less than $1,000.

"We’ve got a limited number of enforcement options," Woodley said Tuesday. "That’s the card that we’ve been dealt, and that’s what we’re playing. There’s lots of ways to drive compliance. Civil penalties are just one of those tools."