quarta-feira, 10 de dezembro de 2014

New Study Estimates There Are Now 5 Trillion Pieces of Plastic in World’s Oceans

 

By Elliot Hannon

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Plastic bags and other trash are collected from the waters of Manila Bay in July 2014.

Photo by Jay Directo/AFP/Getty Images

If the specter of climate change wasn’t enough to get you down, here’s another gnarly bit of environmental news: A new report published on Wednesday estimates there are now 5 trillion pieces of plastic polluting the world’s oceans. That amounts to some 269,000 tons of plastic debris, according to the study published in PLOS One journal. To put it more simply, the Washington Post crunched the numbers and found 5 trillion bits of debris roughly equates to 700 pieces of marine-based plastic for every individual on earth. The greatest bulk of plastic comes from fishing nets and buoys, according to Marcus Eriksen, one of the study’s authors.

PLOS One’s numbers are extrapolated from 24 expeditions where “ships conducting the research traveled the seas collecting small bits of plastic with nets, and estimated worldwide figures from their samples using computer models,” the New York Times reports. Here’s more from the Times on "the problem of bottles, toothbrushes, bags, toys and other debris that float across the seas and gather at 'gyres' where currents converge."

The pieces of garbage collide against one another because of the currents and wave action, and sunlight makes them brittle, turning these floating junkyards into “shredders,” he said, producing smaller and smaller bits of plastic that spread far and wide. When the survey teams looked for plastics floating in the water that were the size of grains of sand, however, they were surprised to find far fewer samples than expected — a one-hundredth as many particles as their models predicted. That, Dr. Eriksen said, suggests that the smaller bits may be being swept deeper into the sea or consumed by marine organisms. The fact that the small plastics are disappearing is hardly good news. In fact, it could be far more troubling than the unsightly mess the plastics cause. Plastics attract and become coated with toxins like PCBs and other pollutants. Researchers are concerned that fish and other organisms that consume the plastics could reabsorb the toxins, and pass them along to other predators when they are eaten."

source to this article : www.slate.com

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