A 'River of Rubbish' Is Flowing From London Into the North Sea

It’s not just the oceans and the Great Lakes that have tons of plastic floating around in them—there’s also London’s “river of rubbish,” recently uncovered by researchers at the University of London and the city’s Natural History Museum.

The fact that a major tributary of the Thames River has a bunch of trash running through it shouldn’t surprise anyone—streams and rivers have been the subject of classroom and Boy Scout cleanup programs since time immemorial—but just how bad it’s gotten should raise some alarm. According to a report published in Marine Pollution Bulletin, most of the trash flowing along the upper Thames Estuary flows invisibly underneath the surface into the North Sea. The Natural History Museum called it a “plastic swamp.”

Using nets designed to catch invasive Chinese Mitten Crabs, researchers caught more than 8,000 large pieces of plastic and trash over a three month period in late 2012. More than 20 percent of waste collected were sanitary objects flushed directly down a toilet and into the river.

“The unusual aspect of the study is that these nets are originally designed to trap fish and crabs moving along the river bed, so we can see that the majority of this litter is hidden below the surface,” said Dave Morritt, one of the authors of the study. “This underwater litter must be taken into account when predicting the amount of pollution entering our rivers and seas.”

The nets weren’t small enough to capture micro plastics, tiny shards of plastic that have contributed to the Great Pacific Garbage Patch and smaller garbage patches in the Great Lakes and other bodies of water worldwide.

“All of this waste, which was mostly plastic, was hidden underwater so Londoners probably don’t realize that it’s there,” said Paul Clark, a Natural History Museum researcher and coauthor of the paper. “This litter moves up and down the river bed depending on tides. The movement causes the pieces of plastic to break down into smaller fragments. These are small enough to be eaten by even the smallest animals, which are in turn eaten by larger fish and birds.”

The study offers some more evidence that garbage patches floating along a body of water’s surface might not be the only thing we have to worry about: Much of the trash could actually be sinking beneath the surface, where it is both harder to clean up and harder to detect.

So far, no one has found a good way of actually cleaning up micro plastics, though several organizations have attempted to clean up the Great Pacific Garbage Patch using nets, the ocean’s currents, and even giant robotic arms. Maybe we should start by severely reducing our reliance on bottled water.