FRANKLIN – Nick Brown flutters his fingers against the deep green water of a 3,000-gallon tank.

Nothing. The water remains as dark and still as a Down East night.

The researcher tries again, and turns to talk about the creature lurking somewhere below – a 70-pound halibut that just might give birth to a groundfish aquaculture industry in Maine.

Suddenly, a bulbous yellow eye breaks the surface, and the halibut appears. A far cry from the white fillets most Americans are used to seeing on ice at the local grocery, this fish is big, powerful and frankly, ugly.

Halibut are the Atlantic’s largest flatfish, with two crossed-looking eyes atop their heads, and sideways mouths that can ingest a whole squid.

Seeing a full-grown halibut – looking like a giant, squashed realization of Pablo Picasso’s imagination – is a bit of a shock for most New Englanders, because the region hasn’t had a substantial wild halibut fishery since before the Civil War.

“It’s not pretty,” Brown acknowledged, “but this is a very valuable animal.”

Today, a wild halibut fishery is thriving in the north Pacific, but the fish are rare at New England markets.

The population crashed during the heyday of 19th century fishing, and although the fish made gains from time to time, it has never recovered its importance as a commercial fish on the East Coast. During the 1990s, federal regulators restricted fishermen’s catch to just one halibut per trip.

In fact, the federal fisheries management agency doesn’t even set Atlantic halibut population goals anymore, because the population is so low, said Terry Frady of the National Oceanic and Atmospheric Administration.

“There’s no way to manage them, because we just don’t see them,” she said.

The state faces the same challenges. Although research boats survey the Gulf of Maine every year, halibut are rarely counted, said Linda Mercer of the Department of Marine Resources.

And although six years of halibut tagging have indicated higher populations than previously believed, the state doesn’t expect halibut to return as a commercially viable species anytime soon.

But even one fish per trip is worth the effort of hauling it in and storing on it ice, because halibut is one of the more valuable fish in markets today. It commands a price of $4 or more per pound wholesale and is served with a flourish in some of the region’s priciest bistros.

Hank Soule, general manager of the Portland Fish Exchange, sees perhaps a couple hundred halibut per year, he said.

“There’s a big market, but we’re not getting it here,” Soule said.

That untapped market is what has drawn businessmen Alan Spear and Doug Morrell into the world of fisheries. Fascinated by Brown’s research, the men have created a new business called Maine Halibut Farms, which they believe can grow enough Atlantic halibut entirely in contained, land-based tanks to hit the market in 2005.

“By next fall, we’ll be selling several thousand fish,” Spear said.

A European halibut aquaculture industry emerged two decades ago, and companies in Canada, Iceland, Scotland and Norway produced nearly 1,000 tons of the fish in 2002, according to industry statistics.

“We’re the first to be doing this in the U.S., but we’re not the first in the world,” Spear said.

That said, Maine Halibut Farms is facing serious challenges. Although Brown has fish at all stages of development at the University of Maine’s Center for Cooperative Aquaculture in Franklin – a facility where university and commercial resources come together to develop new businesses for the state – he has yet to raise a halibut from egg to adulthood.

Only 80 percent of eggs are successfully fertilized, and only 75 percent of those hatch. From there, every stage of this fish’s complex development means further loss. Overall, a 6 percent survival rate is spectacular.

“You need millions of eggs to get tens of thousands of fish,” Brown said. “But once they get to 5 grams, they’re bulletproof.”

The flat fish feel safest lying on the bottom of a tank, which limited the number of fish that could be grown until scientists realized that halibut are just as happy resting on a shelf higher in their tank as on the actual floor – a good example of the endless trial and error crucial to halibut husbandry.

“There’s a lot of cookery, a lot of art to this. It’s not just science,” Brown said.

Maine Halibut Farms is now researching locations for the commercial facility that they hope to build within the next five years. Clean, cold salt water is a necessity, and the company, which has benefited from several local business incentive programs, is committed to remaining in Maine, Spear said.

“We want to be somewhere where we’re wanted,” Spear said.

With the physical and financial infrastructure for research and development in place and natural resources abundant, Maine is positioned to develop second-generation fish farms that benefit from the mistakes made elsewhere.

“The learning curve is so steep and the cost of making a mistake is so high … as new species develop, it’s not the first to do it who becomes profitable,” said Sebastian Belle of the Maine Aquaculture Association in Hallowell.

For now, the fish remain in Franklin, where Brown experiments with different diets in hopes of fine-tuning hatchery techniques before the operation goes commercial.

“Even if it’s a beautiful sunny day outside, it’s cold and damp in here … the halibut love it,” Brown said, slogging across the puddled floor in knee-high boots to give a recent tour.

The first room’s tanks are packed with 11,000 1-year-old fish, most of which are happy to lie on the bottom like so many fallen leaves.

But every so often, a halibut will shoot toward the surface, chased by another. These fish are like teenagers, Brown explained, and if the population density isn’t just right, an aggressor will start nipping off the eyes and tails of its mates.

“There’s a fish with a bad habit in here, a very bad attitude,” he said, pointing out a handful of amputees cruising the tank.

In the next room, larger tanks house mellow 5-year-old fish that range from 8 to 10 pounds. After doing time on research projects in Nova Scotia and New Hampshire, the fish are retiring here to provide eggs for the next generation.

Finally, the decades-old 45- to 75-pound monsters that provide the eggs and sperm for the whole operation swim through dank green water at the room’s far end. These are wild fish, captured by fishermen in the open Atlantic. The process of egg collection takes two men in wet suits, an ambulance backboard and a substantial pulley system.

Even determining the precise window for perfect eggs – neither sticky nor runny – is a challenge.

“She blows up like a little basketball … but preferably, you don’t want to keep going in there, squeezing her and stroking her to see if it’s time,” Brown said. “That’s where all the voodoo comes in.”

Last fall, the first year of spawning, seven fish produced eggs, but only one gave the quality that Brown needs – and those fish later were lost because of a genetic deformity.

“That’s typical. You put in three months’ worth of effort and at the end you realize that something’s wrong and you won’t get another chance until next season,” he said.

But this could be the year, Brown said. Better-balanced diets have all but solved nutritional problems that can lead to deformities and lesser problems, such as oddly mottled skin that some hatchery-raised fish exhibit.

Hatchery-raised fish grow faster than their wild counterparts, and their maturity can be timed to coincide with market demands.

With the environmentally benign reputation that comes with raising his fish in tanks on land, Spear has no doubt that people will buy his halibut, both in the form of filets and as plate-sized whole fish.

With no wild halibut fishery, there is little opposition to the project. Some even argue that this sort of groundfish aquaculture might take pressure off beleaguered wild populations. Others cite the economic benefits of a new species and believe that any conflicts with wild fisheries will be decided by the market.

“I like to think that there’s room for both, that these things work themselves out in a free market system,” said Paul Anderson, director of Maine Sea Grant at the University of Maine and chairman of the now-defunct governor’s Task Force on Marine Aquaculture.

Rebecca Goldburg, an ecologist with Environmental Defense, isn’t sure she agrees, citing patterns established by the shrimp and salmon industries.

Aquaculture has rarely reduced the demand for wild fish. More frequently, it drives down prices, thus increasing demand for all fish, she said.

“There’s a lot of pent-up demand in the world for these types of fish,” Goldburg said.

Though she applauds the idea of using secure tanks with good water filtration systems to grow fish, tank aquaculture relies on the sea for its raw materials – the herring and squid that full-grown halibut consume.

“There aren’t infinite fisheries resources to go into building an aquaculture industry,” Goldburg said.

But soon, with demand for fish rising worldwide and report after report sounding dire warnings about the ocean’s declining population, responsible aquaculture has a role to play, she said.

Encouraging diversity in Maine’s finfish aquaculture industry was a major point in the Maine task force’s recent report, Anderson said, citing the work being done on halibut, cod and haddock. Relying solely on salmon isn’t sustainable, he said.

“They’re in their infancy, but the beginning is here,” Anderson said.