Hungry 'worm' eats away at Big Apple Epidemic: Worm-like mollusks are devouring the wooden piers of New York City's waterfront.

NEW YORK — NEW YORK -- A pier in Sunset Park collapsed, but Denise Virga thought nothing of it. The attack in Bay Ridge seemed to come one day without warning. By the next morning, the 69th Street pier had been closed, and the ferry that shuttled residents from Virga's Brooklyn neighborhood to Manhattan had lost its stop.

"The people of Bay Ridge were very distraught, because we've been cut off," says Virga, who manages the community board. "Suddenly, this pier we've been using for eight years is unsafe, and now we learn it's because of some worm."


Not exactly. The teredo navalis looks like a worm, long and light pink, a tiny sightless creature that grows to more than a foot as it burrows through pier wood. But it's no worm.

"It's the mollusk," grumbles one city engineer, "that swallowed New York."


Thirty years ago, ship captains called New York a "clean harbor" because they could kill off any barnacles or mollusks that had attached themselves to a ship's sides with a quick sail through the harbor's polluted waters.

But beginning with the federal Clean Water Act of 1972, New York's waterways have seen an environmental revival. Now the East and Hudson rivers are the cleanest they've been since the early days of the century.

And the teredos love it. Absent from the harbor since the 1930s, the so-called shipworms have returned in force. Dur- ing the past three years, underwater camera crews documented their feasts on piers from Queens to New Jersey.

"These teredos are in paradise now," says Arthur Strickler, a community worker in lower Manhattan. "Now that the water has finally been cleaned, they're back. You can't win."

While there are a variety of marine borers that attack wooden piers, the teredo has received most of the attention because it doesn't seem to fight fair.

The mollusk is a quiet killer, attacking pier pilings at the murky depths of the mud line. It works from the inside out, burrowing into the middle of the wood and hollowing each piling out. In many cases, it is only after part of the pier collapses that the damage becomes visible.

"This year we fear they've really gone to town, and we're in trouble," says Charles Andreski, a civil engineer for the state Department of Transportation. "Sometimes you feel like there's no stopping them."

The teredo damage comes at an awkward time, as city officials seek to revive New York's waterfront for recreation and as an alternative to the city's jam-packed streets and subways.


New York has added 11 ferry routes in the past 10 years, and there are plans for new river-front parks, anchored by piers, in Brooklyn and on the Hudson side of lower Manhattan.

So far, the only known way of stopping the mollusks is to wrap each pier piling in plastic. But the cost -- about $5 million per pier -- is prohibitive for neighborhoods such as Bay Ridge, which has only been able to secure $2 million for the pier repairs.

Scientists have searched for alternative ways to stop the teredos, but these shipworms seem to have no natural enemies.

"Let me tell you something," says Chee Lai, an engineering consultant who has been studying the teredo since 1989. "If we knew of any natural enemies, we would not hesitate to put some in there."

The teredo navalis is one of the most resilient and aggressive organisms on earth. At 600 million years old, it dates to the pre-Cambrian period. While teredos burrow in wood, turning pulp into bacteria that resides in their gills, their main source of food is the plankton snared in their tails.

Harvard professor Ruth Turner, who has been tracking the mollusks for 50 years, says the Dutch seamen in the 1400s were the first to record the damage the teredos could do. Some historians credit the teredo for the defeat of the Spanish Armada by Queen Elizabeth's navy in February 1588. Whatever the case, they are a longtime nuisance everywhere but the South Pacific, where natives consider them a delicacy.


New York City suffered an infestation of pier-eating teredos during the 1830s, when the City Council declared piers "generally endure only from 14 to 17 years before they are destroyed by worms." But inspectors were slow to recognize the phenomenon when piers began showing teredo damage a decade ago.

"Now," says Lai, the consultant, "we have an epidemic."

In recent months, the focus of teredo hunters has been on the Hudson River side of Manhattan. The shipworms have already collapsed 20 feet of Pier 25, site of miniature golf and the ferryboat Yankee, and nearly all of Pier 26 has been closed as a precaution. Money will be spent to restore parts of both piers, but Pier 32, a hundred yards to the north, has been abandoned to the worms.

"Thirty-two will just stay there, for the wildlife to live around it, until it eventually falls away," says Jim Wetteroth, a contractor who is president of the nonprofit Downtown Boathouse on Pier 26.

Wetteroth's wife, Judy Duffy, says her husband is "a maven of these worms. He's gone nuts."

On a recent Sunday afternoon, as he searches the boathouse for teredo-damaged wood pilings he keeps in odd corners, Wetteroth describes his worries about fighting the worms.


Plastic sheathing of piles is a good step, he says, but even more expensive concrete reinforcements will also be needed. And he talks in detail about the teredo's relentless breeding.

"They start when the water gets warm in April, and from spawning to sexual maturity can be as little as three months."

He glances behind his boathouse, at the chain-link fence erected to keep people off of Pier 26. He shakes his head. "This situation is ripe," he says, "for a population explosion."

Pub Date: 3/19/97