Chuck Bednar for redOrbit.com – Your Universe Online
More than five trillion pieces of plastic garbage weighing a combined 269,000 tons are currently polluting the world’s oceans, according to the authors of a new paper published Wednesday in the open-access journal PLOS ONE.
In the study, Dr. Marcus Eriksen of the nonprofit 5 Gyres Institute in Los Angeles and an international team of colleagues set out to obtain a more precise estimate of the global abundance and weight of floating plastics in the world’s oceans – both large and small. They conducted 24 expeditions from 2007 through 2013 using nets to collect microplastics and data from visual surveys of larger debris to develop a new model of oceanic plastic distribution.
Based on their findings, the authors estimate that there are at least 5.25 trillion plastic particles weighing nearly 270,000 tons currently in the world’s waters. Larger plastics were more abundant near coastal areas, degrading into smaller pieces in the five subtropical gyres. The smallest fragments were found in more remote areas, suggesting that gyres act like paper shredders by turning larger items into microplastics and ejecting them across the ocean.
According to John Schwartz of the New York Times, the researchers reported that the largest source of plastic by weight originated from discarded fishing nets and buoys. While this problem could potentially be solved by creating an international program to pay fishing vessels to reclaim these items, Dr. Eriksen said that this would not address the bottles, bags and other debris that float across the waters and gather where currents converge.
“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 – one-hundredth as many particles as their models predicted,” Schwartz said. Dr. Eriksen noted that this could indicate that smaller bits of plastic are either being carried deeper into the sea, or that these particular fragments are being consumed by marine organisms.
He told Schwartz that the scope of the issue makes it impractical to try and collect the floating trash, but said that his non-profit research and advocacy group had been somewhat successful in convincing health and beauty product manufacturers to stop using small scrubbing beads of plastic. He added that other industries must also be challenged to produce their goods so that the ocean “can deal with [them] in an environmentally harmless way.”
Kara Lavender Law of the Sea Education Association in Woods Hole, Massachusetts, who was not involved in the project, told the Associated Press (AP) that Dr. Eriksen’s team gathered data in part of the world where scientists did not previously have measurements pertaining to floating plastic debris, including the South Atlantic, the Indian Ocean and the Southern Ocean near Antarctica.
Law added that the new paper’s estimates for microplastics (approximately 35,540 tons) was comparable to an a previous study conducted using a different methodology by researchers in Spain. She called it encouraging that the two different methods came up with such similar results, given the difficulty of studying plastic in the ocean, and noted that the knowledge will help scientists better understand how this debris is impacting the environment and possibly even the food chain.
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Nearly 269,000 Tons Of Plastic Currently Pollute The Earth’s Oceans
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