Mexican fishermen are illegally plundering tons of red snapper from the lower Texas Gulf, raising the ire of the U.S. Coast Guard, Texas fishermen, marine biologists and the federal government.

Transcript

LULU GARCIA-NAVARRO, HOST:

Now, off the Texas coast, a multimillion-dollar black market is thriving. For years, Mexican fishermen have crossed into U.S. waters to illegally catch high-priced red snapper. Texas fishermen are outraged, a Mexican cartel is involved and the federal government can't seem to stop it. NPR's John Burnett has our exclusive report.

JOHN BURNETT, BYLINE: The U.S. Coast Guard station on South Padre Island has a one-of-a-kind mission among the 197 stations along the nation's seashores. Their chief enforcement activity entails bouncing across the swells of the lower Texas Gulf in pursuit of wily Mexican fishing boats filled with plump, rosy fish destined for seafood houses in Mexico City and Houston. The chase sounds like this, from a Coast Guard video.

(SOUNDBITE OF ARCHIVED RECORDING)

UNIDENTIFIED COAST GUARD OFFICER: United States Coast Guard. Stop your vessel. Stop your vessel.

BURNETT: It's getting worse. Coast Guard interdictions of illegal fishing boats like this one have soared from nine seizures in 2010 to 148 last year. They detained more than 500 Mexican fishermen. Coast Guard commanders, commercial fishermen, marine biologists and federal officials interviewed for this report say the large-scale illegal harvesting of red snapper is doing great harm to the Gulf.

DAN IPPOLITO: They'll come into, you know, U.S. waters, they'll fish, they'll grab as much snapper as they can, and they'll go head back south before we can detect them. The average catch they'll have on board is 1,000 to 3,000 pounds of snapper.

BURNETT: Lieutenant Commander Dan Ippolito reports that last year, the South Padre station seized 37 tons of marine life from Mexican lanchas, as they're called. I joined them on a recent patrol of the Gulf in a 900-horsepower-fast pursuit boat. They regularly come across trot lines and gill netting that can be 3 miles long. They're both illegal in this part of the Gulf because they kill marine life indiscriminately. First Class Petty Officer Erin Welch is driving the boat.

ERIN WELCH: We find red snapper, sharks, sea turtles. It's incredibly physically taxing on the crew. We have to utilize everybody that's onboard to be able to pull this up.

BURNETT: The snapper poachers are winning this cat-and-mouse game on the warm waters of the Gulf. By the Coast Guard's own reckoning, they detect only about 10% of incursions into U.S. waters. Again, Lieutenant Commander Ippolito.

IPPOLITO: They can go pretty fast, they're pretty maneuverable and they're hard to detect out on the seas just because they have such a low profile.

BURNETT: When the Coast Guard interdicts a lancha, they impound the boat and motor, confiscate the fish and detain the fishermen. But under the Law of the Sea Convention, they're released with no charges. They return to Mexico, where they usually acquire a new boat and do it all over again. The Coast Guard says they've apprehended the same fishermen more than 20 times.

GREG STUNZ: I think there should be more consequences for the individuals doing this, but also those that are probably backing it as well.

BURNETT: Greg Stunz is a marine biologist at the Harte Research Institute for Gulf of Mexico Studies in Corpus Christi, Texas. He shares the widespread belief in the Gulf that the federal government should do more to discourage illegal snapper poaching. The National Oceanic and Atmospheric Administration is the federal cop that deals with unauthorized fishing fleets in U.S. waters. NOAA Fisheries has called out Mexico repeatedly for not curbing its illegal snapper fleet.

Mexico assures Washington that it's cracking down through prosecution and policing. But year after year, nothing changes. A top NOAA official, who was not authorized to speak for the agency, told me they're frustrated by Mexican inaction. Quote, "we've tried to figure out how to make them stop. We've tried plan A, B, C and D, and the Mexican government never did anything."

The homeport of the Mexican lancha fleet is Playa Bagdad, located about 9 miles south of the Rio Grande. Four hundred fishermen live here in wooden shanties with gill nets and long lines strewn about, cur dogs chewing on fish guts and fiberglass boats pulled up on the sand. When I arrived, fishermen were hauling in the day's catch, which included a batch of small snapper.

IDELFONSO CARRILLO: (Speaking Spanish).

BURNETT: "Huachinango - red snapper - it's the best in price and flavor," said Idelfonso Carrillo, a 44-year-old fisherman who owns six boats. He's reclining in a hammock on his front porch after a day on the water.

CARRILLO: (Speaking Spanish).

BURNETT: "The truth is there are red snapper in these waters but very few. You all have them up there," he says, jutting his chin northward. "Here, we're using up all our fish." Carrillo says the fish buyer may pay $75 for a load of puny Mexican snapper and more than triple that, $250, for big U.S. snapper. He continues, Mexican authorities don't do anything to stop them from crossing into U.S. waters.

CARRILLO: (Speaking Spanish).

BURNETT: "There are times when we can't catch anything here, and that's when we have to look for fish up there because we have families to feed. But we run the risk of losing everything," he says. "The Coast Guard takes it all." Carrillo says he's been caught three times, and each time, he had to spend at least $15,000 for a new boat and motor. It's widely suspected among Texas fishermen and law enforcement that the Gulf Cartel is helping the snapper poachers buy new boats. Michael Walker is a charter captain who sees a lot from the helm chair of his 45-foot deep sea fishing boat.

MICHAEL WALKER: That makes me think that - a poor fisherman - you know, three thousand bucks, whatever, for a panga boat, $5,000 to $10,000 for a motor - how can he afford to lose that? Is he making that much, or is it a bigger operation?

BURNETT: Walker is also appalled at the needless slaughter of sea life caused by the floating fishing gear. The illegal fishermen get spooked by the Coast Guard and dash back to Mexican waters, but their gill netting just keeps killing.

WALKER: I pulled one up a few years ago. It had about a dozen dead sailfish in it. I don't know how many mackerel, little sharks, big sharks. It was about a mile long.

BURNETT: The DEA in Houston confirms that the Gulf Cartel has for years used Playa Bagdad as a staging ground to run drugs north in fishing boats. And it's on the rise. A DEA agent says they've seen an uptick in cocaine smuggling along the lower Texas coast. Sources on both sides of the border believe the cartel also takes a cut of the lucrative snapper trade and helps fishermen buy new vessels. A Matamoros native with deep knowledge of the local fishing business, who asked not to be named because he fears for his safety, told me Mexican fishermen are not millionaires. They can't just go out and buy a new boat. There are other interests.

But what really ticks off protectors of the Gulf is how much trouble they all went to to build up a depleted snapper population over the last 30 years. Today, the species has rebounded robustly, says marine biologist Greg Stunz.

STUNZ: So it's somewhat appalling to think we've made all of these sacrifices, are a slap in the face, and then all these fish go out the back door illegally by illegal fishing. And so it's a big problem. It's an unrecognized problem.

BURNETT: In a final twist to the story, Mexico exported 7 1/2 tons of red snapper to the U.S. last year for a value of $50 million. NOAA suspects some of the fish were caught illegally in U.S. waters, iced down in Mexico and sold back to seafood lovers in Texas. John Burnett, NPR News, South Padre Island.

(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.

Correction

A previous version of this story incorrectly said that Mexico exported 7.5 tons of red snapper to the U.S. last year. In fact, 7,500 tons of red snapper were exported to the country.