An Ecuadorean Navy patrol vessel, guided by advanced radar and a small plane, bore down on a ship the length of a football field making a beeline across the Galapagos Marine Reserve—probably the most fiercely protected waters in the world. Filling the freighter’s freezers: 150 tons of dead sharks, most of them endangered and illegal to sell.

Only small pieces off those 6,000 carcasses were actually of much value. The fins.

Shark fins are a delicacy in China, the feature ingredient in an expensive soup served at banquets and fancy restaurants. At peak, dried fins have sold for more per pound than heroin. That price, coupled with high demand from a booming Chinese economy, has created a brutally efficient industry capable of strip-mining sharks from the sea.

With fishing lines over 75 miles long, commercial shark fishermen catch hundreds of sharks in a single try. Tens of millions of sharks are fished from the world’s oceans every year, and some scientists have estimated that number to be over 100 million.

“The amount of sharks that we are pulling in all over the world, it seems insane that there should be any left at all,” said shark conservationist Ben Harris, director of Sea Shepherd Conservation Society’s Panama Chapter.

Shark poaching happens everywhere, from Florida to French Polynesia, but it’s the Pacific Ocean off Central America that has become ground zero in the battle to protect sharks. Even here—by many measures the richest shark waters on the planet—biologists fear relentless overfishing could spiral populations of the most sought-after species into irreversible collapse and take the entire marine food chain down with them.

The big question has become which will disappear first—sharks or the shark fin trade.

“It’s a very close race right now,” said Harris, who has spent decades in small speedboats chasing shark poachers out of Central American marine reserves.

This two-year investigation first published by “Reveal,” a radio show and podcast supported by the Center for Investigative Reporting, found that despite stricter protections enacted by many coastal countries, international trade in shark products remains strong in the Eastern Pacific. Reporting in port towns across five countries from Ecuador to El Salvador showed in some cases new laws intended to curb the slaughter of sharks appear to have had the opposite effect.