Expensive taste

Bridget Macdonald
May 12, 2020 · 8 min read

When U.S. Fish and Wildlife Service Special Agent (SA) Eric Holmes gives a talk on his work, he starts with a question. “Does anyone here eat sushi?” specifying, “Unagi sushi?” — the Japanese word for freshwater eel.

After pausing to acknowledge the nods and raised hands, SA Holmes will ask a follow-up question, “Do you know where that eel came from?”

There are a few possible answers, and one is unsavory.

Juvenile eels, known as “glass eels,” are intercepted at the mouths of rivers in the spring — sometimes illegally — and shipped to aquaculture operations that raise eel for meat. Uwe Kils CC BY SA 3.0

First, some context: while people throughout the world fish for adult eel, consumers overwhelming prefer the consistent taste and texture of eel that have been raised in captivity. Accordingly, the vast majority of the eel consumed globally in forms such as sushi, kabayaki, or pickled fillets, are captive raised primarily in massive aquaculture operations in China.

But aquaculturists have not yet figured out how to breed adult eels in captivity. That means most of the eels we consume, about 95 percent, were actually born in the wild and intercepted as juvenile “glass eels” at the mouths of rivers during their migration inland in the spring.

It’s here that the glass gets cloudy.

Catadromous eel species, those that migrate from saltwater to freshwater, have long been in decline. For most of the 20th century, that was because of dams, which are a dead end for a fish that must swim up a river to complete its life cycle. Today, growing demand for eel meat is compounding the problem.

That’s in part because the traditional source of unagi, Japanese eel, is disappearing. The species native to China, Japan, Korea, Taiwan, and Vietnam was listed as endangered in Japan in 2013, and as critically endangered on the IUCN Red List the following year.

Where does the eel you eat come from? The eel fishery in the United States is restricted due to concerns about over fishing to meet soaring global demand. USFWS.

Years before, the market started to react to the shrinking supply in Asia by shifting to European eels, taxing already stressed populations. In 2007, the European eel was given CITES protection in response to a 90-percent decline over the course of three decades. Since 2010, it has been illegal to export glass eels from the European Union because of plummeting stocks.

Fisheries for the American eel too have been increasingly restricted in response to overfishing. In the United States, it is illegal to commercially harvest glass eels from any state except Maine and South Carolina, both of which have enforced strict quotas in response to overfishing. Other places in the Americas — from Canada south to Venezuela — have glass-eel fisheries governed by quotas, as do nations in North Africa, Oceania, and in Europe outside of the European Union.

But even though the legal supply of glass eels keeps getting smaller, global demand for eel products continues to grow, as does its market value.

A photo showing a fyke net used to trap eels — evidence for Operation Broken Glass, an investigation into the illegal eel market in the United States. USFWS

And what happens when there is a mismatch between demand and supply, set against a backdrop of rising prices? Think back to SA Holmes’ second question, “Where does the eel you eat come from?” For some unknown percentage of the eel we consume, the answer is the black market.

SA Holmes has seen it for himself. He was part of the team of agents from the Service’s Office of Law Enforcement who were behind Operation Broken Glass, a six-year investigation into the illegal eel market in the United States, involving close collaboration with 20 partnering agencies that represented international, federal, state, local, and nongovernmental organizations.

The investigation showed that perpetrators were using the legal fisheries in Maine and South Carolina to launder glass eels from all along the U.S. eastern seaboard. In other words, eels caught illegally in Massachusetts, New Jersey, Virginia, and in other states that have prohibited the commercial harvest of juvenile eels, were counted as part of the legal catch in Maine and South Carolina — if they were counted at all. Untold quantities were packed in boxes as cargo on airplanes, and shipped directly to Asia, labeled as other kinds of fish products.

Another evidence photo showing illicit catch with a fyke net. USFWS

Considering the context in which these crimes took place, such as in the dark, on the water, and across numerous states, the level of trust and coordination it took to align the many partners needed to carry out the multi-year operation is remarkable. The massive takedown in 2014 that involved more than 150 law enforcement officers executing 20 federal search warrants in seven East Coast states was like high-stakes choreography playing out on multiple stages at the same time.

It didn’t go unnoticed. In recognition of the operation, the Service’s Office of Law Enforcement received the Environmental Crimes Award from the International Association of Chiefs of Police, an organization made up mostly of traditional uniformed police officers, with just a small wildlife contingent.

Resident Agent in Charge (RAC) David Sykes managed the Service-led operation. “That recognition speaks to how important communication between these parallel fields was for success in this case,” he said. “Law enforcement officials need to work together across local, state, federal, and international lines in response to the changing nature of wildlife crimes.”

RAC Sykes explained, “In the past, most of our cases dealt with issues like illegal hunting and baiting. Operation Broken Glass was different. The targets weren’t just fishermen bending the law. Some were criminals who got into it because of the money.”

A truck stocked with nets and waders served as a staging area for illicit eel fishing. USFWS

The operation resulted in 22 convictions, each one a felony violation of the federal Lacey Act. This success was also due in large part to the efforts of dedicated trial attorneys from the U.S. Department of Justice Environment and Natural Resource Division.

Most importantly, it resulted in a major disruption in the black market supply chain, in part because it motivated stricter enforcement of the rules. In reaction to the poaching epidemic, Maine instituted a swipe-card system in 2014 to enforce the individual quota and track product from seller to buyer to export. That increased transparency is good for glass-eel stocks, and for glass-eel fishermen who depend upon the legitimate fishery for their livelihoods.

“The problem is,” SA Holmes said, “there will always be people willing to skirt the law to make a profit when there is unmet demand.”

We are eating the evidence.

Eel at ease

Glass eels are multiplicities — they depend on both fresh and saltwater. Their transparency makes them effectively invisible, yet it’s trivial to catch them by the thousands with a net or a trap. Their annual migration is as predictable as any other sign of spring — snow melts, sap runs, crocuses bloom, elvers show up in coastal waters — but where they begin that journey remains unknown.

“It’s been one of the greatest mysteries in marine biology,” said Joel Llopiz, an associate scientist at Woods Hole Oceanographic Institution. “We have long known eels leave rivers as adults to go to the ocean to spawn, but people have been searching for where exactly they go for a long time.”

Both American and European eels spawn somewhere in a vast expanse of the North Atlantic Ocean called the Sargasso Sea. That’s as specific as we can get.

In the early 20th century, scientists narrowed it down after finding larvae of both American and European eel in the Sargasso Sea. But that’s like narrowing it down to an area the size of the Southeastern United States. The Sargasso Sea encompasses more than half of the North Atlantic Ocean, and as Llopiz pointed out, “Eel are larvae for a long time — several months — so finding larvae does not necessarily mean you are close to the spawning ground.”

To this day, nobody has seen adult eels spawn, found adults in the Sargasso Sea, or collected eggs. “There have been huge expeditions dedicated to finding out where spawning occurs, but we’re not much closer to knowing than we were 50 years ago,” Llopiz said.

But scientists have made headway in understanding another astounding facet of eel ecology. How glass eels, at only four inches long, make it from the middle of the North Atlantic Ocean to the U.S. East Coast.

Llopiz explained that a colleague Larry Pratt, a physical oceanographer, was astonished when he learned about this migratory feat. “He wanted to know, how does that happen?”

They decided to join forces with two other scientists — Irina Rypina and Susan Lozier — to figure that out by developing a coupled model combining principles from physics and biology to simulate both ocean currents and the movements of larval fish with different behavioral traits. They programmed some larvae to drift passively, while others were given some swimming ability and a sense of direction. The contrast was stark. “In the passive scenario, hardly any got close to shore,” said Llopiz. “When given swimming ability, the numbers that made it increased substantially.”

There is supporting evidence for this innate navigation ability in nature. “We know that European eel also migrate to the Sargasso Sea, because their larvae have been collected in same areas as American eel larvae,” he said. “But we never see European eels coming onto our shores.”

If European and American eels are starting in the same waters, but end up on different continents, they must be making a choice. “Our guess is that they have some kind of a compass sense,” Llopiz explained. “American eels might preferentially swim west, while European eels might preferentially swim east. Interestingly, hybrids of the two species have shown up in Iceland — right between North America and Europe.”

An evidence photo of live glass eels from Operation Broken Glass. The illicit trade presents a major challenge to species conservation because the impact is hard to quantify. USFWS

Operation Broken Glass revealed that for an unknown number of glass eels, the thousand-plus mile swim driven by an internal compass that evolved over millions of years, ends with a one-way ticket to Hong Kong.

Llopiz said as a scientist, it’s the unquantifiable impact that troubles him. “In the field of larval fish ecology, the assumption is that you have massive numbers of larvae to start, but only a fraction survive to become adults,” he explained.

Eels are a perfect example. Females can lay approximately five million eggs, but only about 30 percent of those hatch. And only a small fraction of those will survive the journey to the mainland. In the model they developed, it was 0.2 percent, and as he pointed out, that’s optimistic. “The model only shows us the effects of the transport processes of ocean currents,” he said. “The number that actually make it to the coast would be far lower because of natural factors like predation or starvation.”

Then factor in dams, habitat loss, water quality degradation, and the unknown impact of the illegal harvest, and it becomes increasingly difficult to see what the future holds for this species.

It’s up to successful law enforcement operations like Operation Broken Glass to help vulnerable species persist by enforcing regulations, and exposing the threat. The work highlighted in this story is just one chapter in the larger fight against wildlife trafficking. Special agents work tirelessly to protect and preserve species that would otherwise vanish as casualties of a demanding trade. During Police Week, we take time to recognize those who continue this fight, and honor those who have lost their lives while dedicated to the protection of vulnerable species.

Learn more about Operation Broken Glass at: https://www.fws.gov/le/pdf/Operation-Broken-Glass.pdf

Conserving the Nature of the Northeast

We conserve nature in the northeast U.S. for the benefit of wildlife and the American people. Love your natural and wild places! Explore the world around you by hiking, fishing, hunting, and volunteering. More info at fws.gov/northeast

Bridget Macdonald

Written by

Always looking for a good science angle.

Conserving the Nature of the Northeast

We conserve nature in the northeast U.S. for the benefit of wildlife and the American people. Love your natural and wild places! Explore the world around you by hiking, fishing, hunting, and volunteering. More info at fws.gov/northeast

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