WASHINGTON — An estimated 269,000 tons of plastic trash is churning around in the world's oceans, most of it in pieces no bigger than a grain of rice, according to a new study from the 5 Gyres Institute.
The non-profit environmental advocacy group's study, published in the PLOS ONE scientific journal, was six years in the making. And while the estimated 5.25 trillion floating plastic particles sounds like a huge number, it's actually less plastic than the researchers expected to find in the seas.
Some of the plastic may be washing up on beaches or sinking to the bottom faster than expected, the researchers said, along with UV degradation, biodegradation, ingestion by sea life and decreased buoyancy due to fouling organisms taking some of the plastic out of circulation. But of the plastic that remains in the water, 92 percent of the pieces are microplastics, “smaller than a grain of rice,” said Marcus Eriksen, director of research at 5 Gyres.
“What we understand now is that plastics, when they get out to sea, start to shred down pretty quickly,” Erikson said.
The scientists also learned that the amount of plastic was similar in the Northern and Southern Hemispheres, which they found surprising “given that inputs are substantially higher in the Northern than in the Southern Hemisphere,” the study says.
Another surprise for the researchers was finding that those shredded bits are not as concentrated in the giant oceanic “garbage patches” that have garnered so much attention in recent years.
“Our findings show that the five subtropical gyres are hardly the final resting places for floating plastic,” Eriksen said. But, he said, that also means that launching an effort to go clean up the garbage patches is probably impractical.
Instead, Eriksen said the plastics industry and environmental groups need to work together to keep plastics from reaching the world's oceans in the first place, from incentivized recovery programs that treat plastic as the valuable material it is to designing products and packaging for easier recovery.
“Disposable design is just not working for the world,” he said. “[The new information] puts the onus on the industry to be more careful and begin to be more proactive. The industry needs to prepare for what's going to come down the pipeline in terms of legislation and public opinion as more and more scientists agree that microplastics are hazardous waste.”
Plastics industry groups say their members are well aware of marine debris problems and support various efforts already underway aimed at keeping plastics out of the oceans.
“America's plastics makers wholeheartedly agree that littered plastics of any kind do not belong in the marine environment,” said the American Chemistry Council in a statement. “Even after plastics have fulfilled their initial purpose, these materials should be treated as valuable resources and recycled whenever possible or recovered for their energy value when they cannot.”
ACC cited efforts supported by plastics companies addressing marine litter around the world, from the Curbside Value Partnership promoting community recycling programs to support for legislation in New Jersey and Illinois to phase out microbeads in personal care products and placing hundreds of recycling bins on California's beaches through the “Plastics. Too Valuable to Waste. Recycle” initiative
“As responsible plastics manufacturing professionals, SPI and its members are firmly committed to addressing marine litter issues with sound solutions that achieve our goal of pursuing zero waste,” said Society of the Plastics Industry Inc. President and CEO Bill Carteaux in a statement. “Operation Clean Sweep, an international product stewardship program launched by SPI in 1994 and currently administered in conjunction with the American Chemistry Council, is credited with reducing the concentration of pellets in the waterways by 80 percent.”
SPI and ACC two of the 60 association signatories from 34 countries to the 2011 Declaration of the Global Plastics Associations for Solutions on Marine Litter, a public commitment to address plastics in the marine environment, both groups noted.
