The outbreak - which shows up as a reddish-brown sheen - was reported around 7 a.m. and confirmed by the New Jersey Department of Environmental Protection, the Coast Guard said in a release. DEP representatives didn't immediately respond to telephone and e-mail messages on the Labor Day holiday.
The swath of red tide stretches from about the site of the Intrepid Sea, Air & Space Museum off Manhattan to Hoffman Island, off Staten Island. Another patch of reddish sheen was reported in Long Island Sound, about three miles south of Jones Beach Inlet, the Coast Guard said.
The algae should drift out to sea and disperse, according to the Coast Guard. Until then, "stay away from it and anything in it," spokesman Charles W. Rowe said. Authorities recommend thoroughly washing anything that comes into contact with it.
Red tide is caused by naturally occurring microorganisms that produce a toxin. It can make shellfish unsafe to eat and cause temporary breathing trouble, burning eyes and skin irritation in people. Sometimes, it also ends up killing fish by depleting oxygen in the water.
The phenomenon occurs at times in many coastal waters, especially when seas are warm.
In 2005 and 2008, hundreds of miles of clam flats were closed for weeks in Maine, New Hampshire and Massachusetts, resulting in tens of millions of dollars in losses. Last year, officials at one point shut down nearly the entire Maine coast to clam and mussel harvesting.
Authorities in New England had braced for widespread red tide outbreaks and potential shellfishing shutdowns there this summer.
But there were only a few scattered, short-lived closures of clam flats this season in Maine, and none in New Hampshire or Massachusetts, officials said.
