A garbage patch to call the Atlantic's own

Posted by Beth Daley The Green Blog/Boston.com

You’ve probably heard of the Great Pacific Garbage Patch – that vast concentration of plastic litter trapped by ocean currents in the Pacific Ocean. Now, researchers at the Woods Hole-based Sea Education Association have found a garbage patch of our own in the Atlantic.

The organization, which runs undergraduate sailing oceanography programs, has been towing nets in the western North Atlantic Ocean from Newfoundland to Venezuela for 22 years. Students have made more than 6,000 tows, pulling up nets to count marine organisms - and plastics - in them, and carefully recording the data.

Their data shows while a whopping 62 percent of the tows contained plastic, researchers consistently saw one area with the highest concentrations: Due east of Atlanta in the western Sargasso Sea.

The exact size of the patch is unknown but the plastic is likely gathering for the same reason the garbage is in the Pacific: Because of gyres, or rotating ocean currents that trap the waste. And while you may expect to see plastic bags and milk jugs floating in a garbage ocean dump, most of the plastic is in tiny bits, broken down by the ocean and elements. Some of the material marine debris but most are plastics that make up common household products from straws to milk jugs.

It’s pretty clear to researchers some land garbage is getting in the sea. And that’s a problem: Plastics can soak up harmful chemicals that fish and seabirds can eat and accumulate. And sometimes, humans eat the contaminated fish.

 “We really decided to look at this more closely,’’ said Kara Lavender Law, Sea Education Association’s oceanography faculty scientist. Lavender and Sea Education colleague Giora Proskurowski recently presented their findings at the Ocean Sciences meeting held by the American Geophysical Union in Oregon. “I don’t know of any such potentially important work that was primarily collected by undergraduates,’’ said Lavender Law.

They also found that the amount of plastic remained constant in their tows even though production and disposal of plastics increased in that time. On other cruises in the Pacific, the researchers found that the plastic isn’t all at the surface – the small pieces appear to go down for tens of feet.

In June, the researchers will launch the first-ever expedition dedicated solely to examining the accumulation of plastic marine debris in the North Atlantic. The trip will explore an area southeast of Bermuda that may be an extension of the plastic patch the organization just identified.