A CARGO PLANE bound for Asia stopped at Miami International Airport for a few hours to refuel on January 24. In its belly was a consignment of 18 large cardboard boxes that, unbeknownst to the wildlife inspectors on duty, contained something highly protected and—in some cases—illegal: shark fins.

"The inspectors were just like, ‘Well, let’s see if there’s anything else in it that is not supposed to be there,’" says Eva Lara, a supervisory inspector with the U.S. Fish and Wildlife Service, which regulates wildlife imports and exports.

The first few boxes Fish and Wildlife Service and Customs and Border Protection inspectors opened held legal wildlife products. But as they dug deeper into the contents, they uncovered shark fins. "Then it became box after box after box of just shark fin," Lara says. Most held upwards of 60 pounds of shark fins—1,400 pounds in all. She says it was one of the largest in-transit shark fin seizures ever made.

Initially, Lara says, they estimated that more than a quarter of the 4,000 fins (representing at least a thousand sharks) were from protected species and therefore illegal. But after weeks of sorting, measuring, and identifying, they concluded that as much as 40 percent were illegal—among them species such as the great hammerhead shark, the silky shark, and the thresher shark. The commercial value of the shipment was roughly a million dollars.

So as not to jeopardize their case or encourage copycats, the Fish and Wildlife Service did not disclose the shipment’s country of origin, destination, what it was labeled as, and what else it contained.

The U.S. isn’t a significant producer or consumer of shark parts, but as a facilitator in the global shark fin market, it’s a transportation "powerhouse," says David Jacoby, a research fellow at the Zoological Society of London. "The fins, whether legally or illegally obtained, have a fast route to their ultimate destination, which is often far East Asia," he says. Americans "have some of the largest airports in the world, that have some of the highest numbers of flights and carriers, that enable things to move very quickly from one place to another."

Sharks have been around for more than 400 million years, but today an estimated one-quarter of sharks, rays, and chimaeras (cartilaginous fish) are threatened with extinction. Some shark populations have declined by as much as 90 percent, largely as a result of overfishing. Because sharks mature slowly and have few offspring, it takes time for populations to rebound: Greenland sharks, which are thought to be able to live up to 500 years, likely don’t even start breeding until the age of 156.

The fish are coveted for their fins, used in shark fin soup, a traditional Asian dish that Lara says can sell for up to $600 a bowl. Their meat, however, has little value, which means that some fishermen engage in finning—slicing the fins off live sharks and tossing the wounded animals overboard, where they sink to the bottom and drown, die of blood loss, or get eaten by other predators. This practice has been illegal in U.S. waters since 2000; various countries and international agreements also restrict shark finning.

In the context of the illegal shark fin trade, says Arthur Florence Jr., branch chief of Agriculture Air Cargo Operations for U.S. Customs and Border Protection, the Miami airport haul was a "drop in the bucket." From 2000 to 2011, countries legally imported an average of nearly 17,000 tons of shark fins a year, according to conservative estimates from the Food and Agriculture Organization of the United Nations. Each year, scientists estimate, tens of millions of sharks are killed in both the legal and illegal shark fin trade—a troubling number, given "the lower productivity of … species common in the fin trade," according to a 2006 study estimating the scale of shark catches worldwide.

Shark fin pathway

In the United States, 13 states and three territories have banned the sale of shark fins. But the country’s location along trafficking trade routes—between shark fishing countries in South and Central America and shark fin markets in Asia—means that significant illegal shipments transit the U.S. by land, air, and sea, according to a 2019 report on the U.S.’s role in the shark fin trade by the Natural Resources Defense Council (NRDC), a conservation nonprofit.

The NRDC report says that during the seven years from 2010 to 2017, between 591 and 859 metric tons of shark fins—from some 900,000 sharks—passed through U.S. ports. Yet those numbers are likely conservative estimates. That’s because the researchers focused only on Hong Kong as a destination, based their numbers on a single global shipping database, and tallied shipping records that explicitly declared the cargo to be shark fins. It’s common for shark fin to be incorrectly labeled as "frozen seafood" or "dried seafood"—or even as something completely unrelated like "tennis shoes," if it’s "full-on smuggling," says Elizabeth Murdock, director of the Pacific Ocean Initiative for the NRDC and lead author of the report.

The U.S. is obligated by both the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), the treaty aimed at ensuring that cross-border trade doesn’t threaten species’ survival, and the U.S. Code of Federal Regulations to monitor in-transit wildlife shipments. Shark fins that are imported and then re-exported must be processed and may need CITES and U.S. permits. Shipments that simply pass through ports should be monitored but often aren’t, Murdock says, adding that if cargo transferred from one plane or ship to another stays under the control of the same shipping company, it likely won’t be inspected.

According to Florence, the inspection in Miami airport was a combination of intel and luck. The Fish and Wildlife Service had tipped customs off that a shark fin shipment was coming, but since the Agriculture Air Cargo Operations department processes more than a hundred in-transit flights daily at Miami airport, catching every illegal shark fin simply isn’t possible. "It’s kind of like finding that needle in the haystack."

Michelle Zetwo, special agent with the National Oceanic and Atmospheric Administration, says she knew there must be occasions when shark fins transited through U.S. ports, but she was surprised at the numbers reported by the NRDC.

In 2017, Zetwo was part of a shark fin bust at the Port of Oakland. The shipment of more than 52,000 pounds of shark fins, labeled as cucumbers and gherkins, was discovered during a routine inspection of a container vessel traveling from Panama to Hong Kong.

As with the 2020 Miami seizure, the discovery largely came down to luck, Zetwo says. "We didn’t know until we did the inspection, and it was just happenstance."

The NRDC report also notes that many exporting countries in Latin America are "major players" in the international shark fin trade and that nations such as Panama and Costa Rica ship as much as one-third to half of their shark fin exports through the U.S.

It’s all but certain that some of these fins are from protected species, Murdock says. Top exporting countries—such as Mexico, Costa Rica, Ecuador, and Peru—fish for species commonly found in the shark fin trade, and many of those are banned from trade without permits, according to a 2018 study.

"We’re pretty sure we just found the tip of the iceberg," Murdock says of the NRDC’s findings. "Just how big the iceberg is hard to know."

If the U.S. wants to actually serve as the shark stronghold it’s widely considered to be, it has a responsibility to act as a "backstop" and catch more of the illegal shark fins, Murdock says. "When we let these shark fin shipments pass through our borders without monitoring them, we’re becoming a weak link in that chain, where we instead should be one of the strongest links in that global supply chain because we have the strong legal framework and the resources to combat that trade."

The Fish and Wildlife Service’s Eva Lara agrees. "You have to say, ‘Not on my watch, not here,’" she says. "If shark fins are coming through the United States, then we have to be an advocate and enforce other countries’ regulations and help the animals survive."

What’s the solution?

"I don’t think any of the wildlife agencies want illegal shark fins to enter U.S. commerce," Michelle Zetwo says. "But having the resources available and the knowledge of when they might be coming through our ports—it’s important, and we don’t always have that information in a timely fashion."

Because trade is so difficult to monitor, the best way to address the U.S.’s unintentional role in the global shark fin trade is a blanket ban, Jacoby says.

It now takes shark fins about four flights to reach Hong Kong from Latin America, Jacoby found in an analysis of airline trade networks. He determined that a U.S. shark fin ban would slightly increase the necessary number of flights and raise the overall cost of transporting fins.

"If you don’t go via these big hubs, it becomes more expensive to get from A to B," he says. "I think as that burden becomes more and more, the incentive to actually fish and ship in the first place, hopefully, will start to come down a little bit."

After the Miami discovery in January, it was a bittersweet moment to see all the shark fins laid out, says Arthur Florence, of Agriculture Air Cargo Operations—sweet that they caught the illegal fins, bitter to think of the dead sharks. "It was a ton of juvenile fins that were actually cut off," he says wistfully. "Some of those sharks take about 20 years to reproduce."

That’s why it’s urgent to act now because sharks "don’t bounce back quickly," Jacoby says. "We can only drag our heels for so much longer, before we don’t have a problem because there aren’t any sharks anymore."