Can ‘electric oysters’ restore New York’s waters?

James Cervino, a professor of marine biology at Pace University in New York City, thinks a little electricity could go a long way in helping oysters return to the city’s waterways.

On a recent morning in College Point, Queens, just a few blocks from where he grew up, Professor Cervino shows a visitor what he calls “the electric oyster reef project.” He’s installed a series of spiral-shaped bands of metal in the shallow water. At low tide, they jut from the water like giant strands of DNA.

“I had a dream one night of helixes coming out of the water,” he says. In retrospect, the shape “is actually not such a great idea.” But the concept, he says, is.

Solar panels perched atop poles provide the helixes with a low voltage. The current causes a chemical reaction in seawater, and limestone builds up on the electrified metal. The ready supply of shell-building minerals, Cervino says, will help the oysters, decimated here and elsewhere by overharvesting, pollution, and disease. Cervino’s collaborator, Thomas Goreau, president of the Global Coral Reef Alliance, has shown that electrification can help damaged coral reefs regenerate. It seems to be helping the oysters here as well, he says. Oysters in mesh sacks at the spirals’ base are alive while control oysters – those farther from the electric field – have all died.

He points to a lime-encrusted bit of metal: “That’s how I know it’s working,” he says. And then he adds, “If we recreated oyster reefs, we’d clear the water.”

This project is part of a larger movement along the East Coast and elsewhere to restore ecosystems drastically altered by human activity. Restoration almost invariably begins with so-called keystone species, the humble filter feeders once so numerous along the eastern seaboard that they cleaned entire bays within days.

Don Boesch, president of the Univer­sity of Maryland Center for Environ­­mental Science in Cam­bridge, Md., calls oysters “the coral reefs of the East Coast.” Oyster-restoration projects are at various stages in Florida, South Carolina, Chesapeake Bay, New York, and New Jersey. Before European settlement, oyster reefs covered some 350 square miles around New York. Their importance as a species stems from their ability to filter large amounts of water. Depending on its size, an oyster filters between 5 and 50 gallons of water daily. Water now murky with algae and other organic matter was, in earlier times, almost certainly clear.

“I suppose that when [Henry] Hudson sailed through the harbor, you could see right through to the bottom,” says Mark Kurlansky, author of “The Big Oyster: History on the Half Shell,” the tale of New York City’s long relationship with the mollusks. Their absence, he says, is “a symbol of how badly we’ve cared for New York.”

By the 1930s, oysters were deemed too dangerous to eat in New York. A few decades later, they were ecologically extinct from the city’s waterways. Thanks to the Clean Water Act, conditions have improved a lot since the 1970s when, as Mr. Kurlansky recalls, the water was black “with this sort of mother-of-pearl purplish green thing on the surface.” Says Cervino, “I’ll go swimming in this.” As an adolescent, he’d studiously avoided it.
Any restoration effort faces some serious obstacles.

“Once you mess around with nature – if you remove something from the food chain – that space isn’t reserved for it to come back,” says Mr. Kurlansky. “It’s very difficult to reverse these things because the absence has had all sorts of repercussions in nature.”

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