SAN JUAN, Puerto Rico » Researchers are warning of a new blight at sea: a swirl of confettilike plastic debris stretching over a remote expanse of the Atlantic Ocean.

The floating garbage—hard to spot from the surface and spun together by a vortex of currents—was documented by two groups of scientists who trawled the sea between scenic Bermuda and Portugal's mid-Atlantic Azores Islands.

The studies describe a soup of microparticles similar to the so-called Great Pacific Garbage Patch, a phenomenon discovered a decade ago between Hawaii and California which researchers say is likely to exist in other places around the globe.

“;We found the great Atlantic garbage patch,”; said Anna Cummins, who collected plastic samples on a sailing voyage in February.

The debris is harmful for fish, sea mammals and, at the top of the food chain, potentially humans, even though much of the plastic has broken into such tiny pieces they are nearly invisible.

Since there is no realistic way of cleaning the oceans, advocates say the key is to keep more plastic out by raising awareness and, wherever possible, challenging a throwaway culture that uses nonbiodegradable materials for disposable products.

“;Our job now is to let people know that plastic ocean pollution is a global problem—it unfortunately is not confined to a single patch,”; Cummins said.

The research teams presented their findings in February at the 2010 Oceans Sciences Meeting in Portland, Ore. While scientists have reported finding plastic in parts of the Atlantic since the 1970s, the researchers say they have taken important steps toward mapping the extent of the pollution.

Cummins and her husband, Marcus Eriksen, of Santa Monica, Calif., sailed across the Atlantic for their research project. They plan similar studies in the South Atlantic in November and the South Pacific next spring.

On the voyage from Bermuda to the Azores, they crossed the Sargasso Sea, an area bounded by ocean currents including the Gulf Stream. They took samples every 100 miles with one interruption caused by a major storm. Each time they pulled up the trawl, it was full of plastic.

A separate study by undergraduates with the Woods Hole, Mass.-based Sea Education Association collected more than 6,000 samples on trips between Canada and the Caribbean over two decades. The lead investigator, Kara Lavendar Law, said they found the highest concentrations of plastics between 22 and 38 degrees north latitude, an offshore patch equivalent to the area between roughly Cuba and Washington, D.C.

“;It's shocking to see it firsthand,”; Cummins said. “;Nothing compares to being out there. We've managed to leave our footprint really everywhere.”;

As much as 80 percent of marine debris comes from land, according to the United Nations Environmental Program.

Still more data is needed to assess the dimensions of the North Atlantic patch.