Henry MacVane sets up his gear along a stream bank at midnight just outside the town of Freeport, Maine. He dunks his dip net in and out of the water for hours, and occasionally stops to inspect his catch—a writhing pile of tiny, translucent glass eels.

Maine fishermen have been catching glass eels, or “elvers,” and selling them at modest market prices for years. Recently, however, steep demand from Asia has caused prices to skyrocket. They climbed from under an average of $200 a pound in 2010 up to $2,600 a pound in 2012. “During the peak of elver fishing last year fishermen commonly made $3,000 or $4,000 a night,” says MacVane, a 23-year-old, third-generation lobsterman. “The big guys made $10,000 a night.” Last season he caught a little over 10 pounds of glass eels in several weeks’ time and made $23,000.

Glass eels measure no bigger than a pinkie and look more like vitreous earthworms than fishes. They are the juvenile life stage of Anguilla rostrata, the American eel, which can grow up over a meter long. They’re nocturnal creatures, so MacVane fishes for them while others sleep. “I forgot how exhausting it is,” he says.

The sky-high prices have also attracted attention from government, media, poachers—and scientists. Fisheries biologists are worried about the American eel’s survival because surveys show a dangerous decline in population size. They recommend taking measures to protect the species. “We’re supposed to manage fisheries on the precautionary principle,” says eel biologist James McCleave of the University of Maine, “If the trend is down, we don’t say it’s okay.” This year a regional management board tightened eel fishing regulations and it may decide on August 7 to shut down Maine’s glass eel fishery altogether.

Unsurprisingly, fishermen argue against the proposal to close the fishery—their livelihoods, after all, are at stake. They say that the eel fisheries in Maine are healthy and that there is no reliable evidence that their fishing significantly harms the species. In fact, they point to other factors, such as the thousands of dams that clog east coast watersheds, as far more problematic for eel populations than fishing.

Although scientists are confident that the American eel desperately needs protection, they do not have definite answers to counter fishermen’s arguments against closing the fisheries because eels are a data-poor species. The situation has set up an awkward moment in the politics of conservation. Are the proposed regulations on eel fishing a good idea? And how should political leaders make such decisions in the absence of firm scientific answers?

Eel desire
The American eel is an enigma. It has such a complex life cycle that biologists do not possess some basic information about the species. It ranges from Brazil to Greenland, yet despite this wide geographic range, genetic evidence indicates that every American eel somehow belongs to one gigantic interbreeding population. The eels hatch in the warm, blue brine of the Sargasso Sea south of Bermuda and then disperse to estuarine and freshwater habitats where they spend most of their lives before migrating back to their birthplace to spawn and die. The spawning is something of a mystery, however, because scientists have yet to witness it—despite investing many hours and funds trying—because the eel’s breeding ground is remote and difficult to sample.

Eels once flooded the U.S. east coast’s rivers, streams and estuaries. “Historically, they were one of the most abundant fish in our freshwater ecosystems,” McCleave says. They served as a critical food source for Native Americans and colonists, and the Passamaquoddy tribe in Maine still harvests eels today. But most Americans have paid little attention to eels because the fish typically had little market value.

Then, a few years ago, two events transpired to spark a virtual gold rush for glass eels in small-town Maine. First, the European Union banned exports of the European eel in 2010 due to its dangerously depleted population. Then the 2011 earthquake and tsunami ravaged Japan, decimating its eel farms.

This confluence of events created a massive shortage for Asian aquaculture farms, which raise the tiny eels to adult size and then sell them, mostly within Asia. Japan, the biggest eel consumer, eats 100,000 tons of unagi per year—more than two thirds of the worldwide eel catch. Its government has invested significant money into finding ways to breed and raise eels in captivity but scientists have yet to hit on a commercially viable method. The Japanese and everyone else who eats freshwater eels thus rely on wild-born fish.

Without their regular supply from Asia and Europe, dealers turned to what they consider a less desirable species: the American eel. Maine and South Carolina are currently the only two states with legal elver fisheries, and only the former has a substantial catch, so Maine became a big eel supplier and the price for these fish began to skyrocket, increasing 13 times over between 2010 and 2012 and peaking at $2,600 a pound. Without any state limitations on catch fishermen netted more than 20,000 pounds of eels and earned nearly $38 million dollars in 2012. They fared almost as well in 2013, with almost 20,000 pounds worth $33 million dollars. Elver fisherman Darrel Young says he made over a $100,000 in a season last year.

Although Maine allowed fishermen an unlimited catch, it also required they have a glass eel fishing license. The state authorizes only a few hundred licenses every year, so inevitably the tantalizing prices and restricted entry attracted poachers. In Maine as well as in nearby states, poachers blocked off entire streams with nets and even stole other fishermen’s catch. Authorities arrested one man who did not have a commercial license and swam upriver in a wet suit to capture eels at a fish ladder, an off-limits fishing zone. “When you catch people poaching, they tell you, ‘Hey, you can’t blame me for trying. I’ve got bills to pay and I made $8,000 last week,’” says Rene Cloutier, a lieutenant with the Maine Marine Patrol. Robbers have also struck; a Maine dealer recently had 50 pounds of elvers, worth over $140,000, stolen from her home, according to a PBS documentary.

The high value of glass eels has brought a load of trouble to Maine but it’s also a godsend for licensed fishermen and their communities. Until recently many elver fishermen scraped together a living with multiple jobs: They fished for other species like lobster, worked construction, harvested periwinkles, gathered seaweed. Some of them supplemented their income with welfare and food stamps.

Now, fishermen can support their families, pay off taxes, help put their kids through college and buy new cars or tractors for their farms. “Elver fishing dumped millions of dollars into a poor state,” says fisherman Jeff Pierce, head of the Maine Elver Fisherman Association, “It’s a huge success story. It’s given people pride.”

Keeping it eel
In the late 20th century, years before elvers attracted local and international attention, fisheries biologists began to take a closer look at the American eel. They knew the species faced a multitude of threats: pollution, fishing, hydropower dam turbines and major habitat loss from deforestation and dams.

Biologists realized these combined pressures did not bode well for the species. “When you look at the whole eel population over multiple decades, there’s been an obvious decline over time,” says Genny Nesslage, senior stock assessment scientist at the Atlantic States Marine Fisheries Commission (ASMFC). In the 1990s the commission, which manages fisheries for the U.S. Atlantic coast, made the American eel one of its priorities. It gathered available population data (chiefly, fish surveys collected by state or federal biologists) and published a stock assessment in 2012, which evaluates the state of the eel population today compared with past decades.

The ASMFC acknowledged the difficulty of evaluating this species, given the sparse population data and elusive life history details. It does not even have enough information to determine whether the species is overfished or if fishermen remove eels at a sustainable rate. “Because it’s a data-poor species, we’re unable to come up with benchmark reference points that you typically see in fisheries management,” says Kate Taylor, senior fishery management plan coordinator at the ASMFC.

Both the commission and outside fisheries biologists agree, however, that the evidence overwhelmingly indicates the American eel is depleted compared with historic levels, and something needs to be done to protect it. “Eels are a keystone species,” McCleave says, “because they’re so abundant—if you remove them, a whole bunch of predator–prey relationships fall apart.”

Even with the stock assessment, biologists still do not know how much each threat—dams, pollution, fishing and others—harms the fish. They just do not have enough data. “It’s at the point where we recognize what the threats are,” says Jeff Kipp, an ASMFC stock assessment scientist, “But we don’t know their impact yet.”

Elver fishermen take issue with this discrepancy because they think factors other than fishing, such as dams, pose a bigger problem for eels, especially in Maine. “There are literally tens of thousands of dams up and down the east coast—large ones, small ones—and most of them are in the Northeast,” says U.S. Geological Survey (USGS) research ecologist Alex Haro, “Few have passage structures for eels, because eels have just recently come on the radar screen in terms of a species of interest.”

U. Maine’s McCleave believes that habitat loss from these dams presents a major threat to eels. “There’s impairment or complete blockage of fish passage in something like 80 percent of the American eels’ range, and that’s just incredible,” he observes.

Studies have hinted indirectly at the heavy toll dams take on eels. In 2004 USGS researchers studied the impact of a dam removal in Virginia and found a significant increase in the numbers of eels in the watershed just two years later. “Our study shows that the benefits of dam removal can extend far upstream,” Nathaniel Hitt, a USGS biologist told National Geographic, “American eels have been in decline for decades and so we’re delighted to see them begin to return in abundance to their native streams.”

Hydropower dams create a more gruesome problem: on their return to the Sargasso Sea, adult eels follow the path of dominant flow downstream through the dam’s intake system and get chopped up in turbines. Hundreds, if not thousands, of eels die every year because of turbines, according to Haro. “There are even several hydropower dams that have 100 percent mortality because they weren’t designed to pass fish at all, and yet the eels try to go through them and it’s disastrous,” he says.

In spite of the impact of dams and other threats, Maine fishermen say that the state’s eel population appears healthy to them and they are not overfishing the species. “Last two years were the best fishing I’ve ever seen,” says Darrell Young, a seasoned elver fisherman, “If there were no eels, the elver fishermen would be first people bitching about it.”

The problem, according to fishermen, is that managers see them as low-hanging fruit—it’s easier to deal with fishermen who have little monetary and political power rather than confronting formidable multinational dam owners. “The comment from the [ASMFC’s] technical committee is that it would be easier to manage this fishery if it were closed. Well, no shit!” Pierce says, “This fishery has done a lot for people and it’s really sad they want to take this away from people.”

Unknown fate
This past winter the various stakeholders—the ASMFC, the State of Maine, commercial elver fishermen and Native Americans from the Passamaquoddy tribe—fought bitterly over elver regulations. The state ultimately worked out a deal with the commission this spring to keep the fishery open with a quota: an approximately 35 percent cut in last year’s total catch, to be divvied up among elver fishermen. Elver fishermen were not pleased about the decision. “They were heavy-handed,” Henry MacVane says.

On August 7 the ASMFC will vote on further regulations, including the question of whether to impose an even stricter quota on Maine’s elver fishery or even to completely shut it down. Pierce and other fishermen are working to develop a statewide glass eel management plan to prove to the commission they can run a sustainable fishery. Their efforts could be in vain, however, because the U.S. Fish and Wildlife Service may list the American eel under the Endangered Species Act, which could potentially prohibit eel fishing in all states. The agency will decide whether to list the eel in 2015.

The ASMFC faces a difficult decision this month, especially because it is under political pressure from other states that want to open up their own elver fisheries. “Managers have to consider not just biological objectives but also social and economic objectives,” says Yong Chen, fisheries biologist at U. Maine. “You can’t just say, ‘Let’s shut down the fishery,’ because too many people depend on that fish.”