Sushi lovers will tell you that full-grown eels, called unagi, are pretty tasty. That's why Sara Rademaker started raising baby eels a few years ago ... in her basement near the coast of Maine.
"It was like dingy stones, a dirt floor and a glorified large aquarium with a couple of tanks," she says. "And also we had butchered a pig. So that was hanging. It was quite the scene ... with like an exposed light bulb."
Each spring, Rademaker has watched as local fishers netted baby eels from Maine's clean, cold rivers and sold them to unagi-loving Asian nations. Some years, those foreign importers pay thousands of dollars per pound, each one containing about 2,500 of the toothpick-thin, transparent wrigglers often referred to as "glass eels."
The Asian buyers grow them to full-size, with the mature product fetching as much as 10 times the original purchase cost.
"Why not keep that value at home?" Rademaker thought, and started American Unagi, which appears to be the first commercial attempt in the U.S. to grow baby eels, indoors, to maturity and then market them to American buyers.
Last month, she took over an indoor "recirculating aquaculture system" at a University of Maine research center not far from Acadia National Park. It's a small warehouse, with rows of shoulder-high circular green tanks, pumps and hoses — plus some proprietary technology that Rademaker is developing.
The tanks brim with wriggling eels, some thin as pencils, some fat as cigars.
"We've got thousands," she says, smiling down almost fondly at her charges. "Thousands of fat little eels."
Eels are actually fish, she explains, with fins and gills.
"If you look closely, they almost have puppy dog eyes, and a little smile, the way their jaw is shaped," she says.
Rademaker drops in a pinch of microalgae and fish meal. She says the right feed is essential to the flavor and protein content that will make the eels marketable. They thrash around in the tank, eager for the food.
"That's the sign of a happy eel: when they swarm and feed really excitedly, almost splashing the water," she says.
These eels, like all Anguilla Rostrata, started out in the Sargasso Sea, off Bermuda.
"They spawn there," she says. "And then when they hatch, they just drift on the currents. They don't know if they're going to land in the Caribbean or Canada."
Or in a fisherman's net at the mouth of a river in Maine.
Wild eel populations are under stress worldwide, and many countries are restricting harvests. But Rademaker recently won federal permission for Maine's elver fishers to exceed their annual quota by 200 pounds. Then she will raise them to maturity.
She hopes to sell 20,000 pounds this year. The question is: Who will eat all of that American unagi?
The patrons of Sammy's Deluxe restaurant, in downtown Rockland, for one. Owner and chef Sam Richman doesn't serve it up sushi-style though. Instead he smokes it, European-style.
"It honestly winds up tasting not dissimilar to a mild kielbasa or a mild bacon. It's really juicy," Richman says.
Customers are intrigued "because of the really great story of American unagi," he says. "Everybody's familiar with elvers and the value of that fishery ... but haven't really eaten them, so I think they're eager to give it a try."
They'll be joining a growing world population that's hungry for more and more seafood, and increasingly able to pay for it. And in the U.S., domestic supply is nowhere near meeting demand.
"We already import about 90 percent of our seafood," says James Anderson, a former World Bank aquaculture advisor who directs the Institute for Sustainable Food Systems at the University of Florida. He says the U.S. needs to step up its efforts to bring aquaculture back home.
"In states like Maine, there's been a lot of progress, but elsewhere it's been almost no growth," he says. "And we just have chosen as a nation to depend on imports."
In Maine, Rademaker is doing her part to change the equation. She's already lined up investors for a full-scale commercial facility.
"That's our goal. This is a stepping stone to our commercial production," she says. "We're planning to be online next year."
She says she can boost output more than tenfold — selling more than 250,000 pounds of eel in the U.S. next year at as much as 25 dollars a pound. For now, though, she's barely even marketing this first crop of around 20,000 pounds — because she doesn't want to create demand she can't yet meet. Yet.
This story is part of Maine Public Radio's series Aquaculture's Next Wave, which explores how old ways of farming seafood are making way for new technologies, sparking opportunity — but also controversy. You can listen to the audio here.