Scientists Test Once-Polluted Harbor’s Crop Potential
There was a time when all Boston Harbor seemed able to produce was stink and slime.
Now they want to raise fish there.
In the first such urban aquaculture project in the nation, Massachusetts Institute of Technology scientists are raising a tasty type of fish called red drum in a tiny trailer on an old Navy pier, using untreated harbor water--so far, with no ill effects.
“We’re really trying to explore what the worst situation is,” said Cliff Goudey, director of MIT’s Center for Fisheries Engineering and the captain of the cramped metal shipping container that has been converted into a harbor-side fish factory.
The 120 fish, each about 10 inches long, seem right at home in their 300-gallon tanks, where the water is warmed with simple home aquarium heaters and circulated through a homemade system of plastic pipes.
They’re happier, at least, than the codfish that were the first to be raised when the project began in 1996. They died within six months--not because the water was polluted, but because it was too warm for the cold-water species.
Warmer water red drum were next in the pool, since it’s easier to heat the tanks than cool them. So far, they’ve doubled in size since August on their diet of catfish food released automatically by a machine six times a day.
In fact, the muggy former shipping container, 20 feet long by 8 feet wide, needs little maintenance. Between 5% and 10% of the ocean water is replaced daily at high tide, and the only treatment comes before the excess is returned to Boston Harbor, when it passes through a filter system to remove ammonia excreted by the fish.
Such strict environmental controls are required as part of the multibillion-dollar effort that helped clean the notoriously filthy harbor. Lobstermen are setting traps again, and harbor seals have returned.
“Those are pretty good monitors of the quality of the water,” said Jerry Schubel, president of the New England Aquarium. “Ten years ago, it was one of the most polluted harbors in the United States, and now it’s one of the cleanest.”
Meanwhile, aquaculture has grown to a $30-billion industry worldwide, helping meet an international demand for seafood that is projected to rise by 19 million tons, to 91 million tons, within the next 15 years.
“What is different is that we’re doing it here, that we’re bold enough to try it in Boston Harbor,” Goudey said, standing on his pier with the city skyline in the background.
The MIT project and another planned by a chain of seafood restaurants in South Boston call for raising fish in harbor-side tanks with closed-loop recirculating water systems. Empty warehouses would provide the perfect sites, energy and food expenses would be minimal compared to growing fish outdoors, and the water could be treated and reused.
Work is well underway on a large-scale space in an abandoned Navy building, where 40,000-gallon tanks 30 feet in diameter will be used to grow haddock. The building was made available by the National Park Service, and Goudey and some students have refurbished it.
If that expansion is successful, Goudey said, he hopes that it will persuade entrepreneurs to open profit-making fish factories on Boston Harbor within the next year.
Haddock is a popular New England dish, and no less a culinary authority than chef Paul Prudhomme recommends red drum in his blackened redfish recipe.
City officials hope to attract an aquaculture institute that could produce seafood for local restaurants, provide education and training and serve as a tourist attraction. Mayor Thomas Menino is eyeing an unused 50-million-gallon 19th-century waste-water treatment tank on Moon Island in the harbor as a potential aquaculture site.
There’s another advantage to urban aquaculture, according to Goudey: Cities provide a huge ready market for fresh fish, with no need for expensive and time-consuming transportation. And the public’s appetite is heightened, he said, after years of restrictions on commercial fishing grounds.
The drawback? Fish farms could undercut the price paid to already struggling commercial fishermen.
In the meantime, the red drum grow in their tank. They eventually will be tested for metals or other contaminants, but for now are small enough to be protected from the frying pan.
“It would take a lot of these fish to make a sandwich,” Goudey said.