NEW YORK — In the basement of an ivy-covered building on the surprisingly leafy campus of Brooklyn College is something even more surprising: thousands of tilapia packed tighter than a subway car into 300-gallon fiberglass fish tanks.

Overseeing this watery domain is Martin Schreibman, a professor emeritus and the director of the college's Aquatic Research and Environmental Assessment Center.

A mild-tasting fish that was unfamiliar here a few years ago, tilapia is increasingly available in the United States, almost all of it farmed and imported from China and Central and South America.

Schreibman hopes to change that. He believes that urban aquaculture — raising fish in big tanks in places like New York — could be the the solution to the overfishing of wild populations and provide Americans with jobs and healthy food.

"We're subsidizing everybody in the world to grow fish that we can buy back from them," he said. "It doesn't make any sense to me. We should be creating jobs here."

Environmentalists say Schreib-man's ideas have merit, but people who actually grow fish in contained systems say competing with cheap labor and production costs overseas would be a tall order.

Schreibman, a genial 70-year-old in Birkenstocks and a Hawaiian shirt, didn't set out to be the Johnny Appleseed of tilapia. He conducts research on aquatic animals, including horseshoe crabs, octopuses and chambered nautiluses, and his interest in fish farming was an offshoot of research into tilapia reproduction.

"It became natural to try to breed them in captivity by controlling the reproductive cycle," he said.

GOOD FARM FISH

Tilapia are a good fish for farming because they are disease-resistant and very efficient at converting feed to body mass.

And Schreibman believes that New York City, with its countless restaurants and its immigrants from fish-eating parts of the world like Asia, is ripe for aquaculture development.

The tanks could be situated "in a variety of diverse places, from warehouses to skyscrapers, from green fields to brown fields," he argued in his contribution to a 2005 book, "Urban Aquaculture."

The Brooklyn College tanks use a recirculating water system that is controlled for temperature, salinity and other factors. The tilapia are fed fish meal pellets except for the tanks that are on an experimental soy diet.

Academic rules don't allow Schreibman to sell his tilapia, which he donates to homeless shelters and staff fish fries.

But he believes that fish raised under similar conditions would be superior to the widely available imported product.

"You have no regulations or idea of what fish are being grown on in China or Ecuador or Colombia or wherever it's coming from," he said. "These animals are grown in contained systems. The water quality's monitored second to second."

Jennifer Dianto, who manages the seafood watch program at the Monterey Bay Aquarium, said there are concerns about farmed tilapia in China escaping and possibly breeding with wild fish. She said a system like Schreibman's that uses tanks is better.

"Plus if you have property that's not being used for anything else, what better way to create food for consumers?" Dianto said. "That's a great use of space, in my personal opinion."

NO. 6 IN POPULARITY

Americans ate about 300 million pounds of tilapia in 2005, making it No. 6 on the list of seafood consumption by weight, just behind catfish.

But not everyone's a fan. Top chefs disparage it, and they're not crazy about the idea of growing fish in a tank.

"The problem with tanked fish is it tastes like tanked fish," said David Pasternack, the award-winning chef at Esca in Manhattan's theater district. "There are people that like it, but people also like McDonald's."

A more serious hurdle for a scheme like Schreibman's is economics.

"This is not a business that you put in the middle of a city," said Bill Martin, president of Blue Ridge Aquaculture in Martinsville, Va., which produces just under 4 million pounds of tank-grown tilapia a year. "The electric and power and sewer rates are astronomical."

Jim Carlberg, president of San Diego-based Kent Seatech Corp., which produces hybrid striped bass, said U.S. fish farms can't compete with overseas farms with their low labor costs — $1.50 a day in China, for example.

"It's true about a lot of other things," Carlberg said. "We're driving Korean cars."

Schreibman said it might be possible to develop a niche market for urban tilapia like the market for higher-priced organic food.

"The profit margin is always very close, and government ... incentives would help to make these ventures attractive," he said.

After leading a reporter and photographer on a tour of his lab, Schreibman went to a refrigerator and got out a pound of tilapia fillets for each.

It was very good.