Chuck Bednar for redOrbit.com – Your Universe Online
Researchers who were surprised at the low quantity of plastic refuse while preparing a global ocean trash map last summer have discovered where it all went – it decomposed into miniscule fibers and was buried in deep water sediment in distant corners of the planet.
Richard Thompson, a marine biologist at Plymouth University who was not involved in the preparation of the original study, reported in this week’s edition of the journal Royal Society Open Science that microplastics have been discovered in remote marine habitats.
According to National Geographic, the finding helps to explain why the first research team found less plastic garbage floating in the ocean waters than expected, especially considering that plastic production has spiked by 400-percent in recent years.
However, it also raises a new problem: could these potentially toxic little fibers contaminate the food chain? Previous research has already indicated that fish, birds and other forms of marine life consume plastic, and now Thompson and his colleagues have discovered a greater-than-expected accumulation of the substance.
In fact, the authors of the new study report that there are approximately four billion plastic fibers, most of which are no larger than three centimeters and no thicker than a human hair, in every square kilometer of deep ocean. Furthermore, they found that the fibers are four times more abundant in the deep sea than they are in coastal or surface waters.
Chelsea Rochman, a marine ecologist at the University of California-Davis who studies the effect of plastic ingested by fish and shellfish, told Parker that she was not surprised that they had located the missing plastic refuse. “Every time they look somewhere for plastic debris, they find it,” she said. “What is surprising is that what they are finding is that most of this is fibers.”
Thompson and his colleagues collected and analyzed samples from 16 sites during seven journeys in the Mediterranean Sea and in the southwest Indian and northeast Atlantic Oceans from September 2001 and August 2012. Those samples were collected by a remotely operated vehicle in submarine canyons, continental slopes, and basins.
Samples obtained from four locations in the Indian Ocean indicated that microfibers had accumulated on the surface of coral, Parker said. The majority of them were blue, black, green, or red, though pink, purple, and turquoise fibers were also collected, according to Thompson. More than half of the fibers also contained the synthetic polymer rayon, he added.
Lucy Woodall, a zoologist at the Natural History Museum in London and a member of the research team, said that it was “alarming to find such high levels of contamination, especially when the full effect of plastics on the delicate balance of deep sea ecosystems is unknown.”
The global ocean trash map that inspired Thompson’s new study was prepared by a team led by Spanish scientist Andres Cozar Cabanas and published by Proceedings of the National Academy of Sciences in July. In it, he and his co-authors reported finding evidence of microplastics in five large accumulations matching up with the large open-ocean currents called gyres in 2010.
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Where is all the plastic sea trash hiding?
Christopher Pilny
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