Researchers were able to pinpoint the sources of ocean "garbage patches" made up of plastic and other floating debris.
Researchers created a "roadmap" for developing ocean-scale solutions for the trash that has been carried into all five of the world's major ocean gyres, the University of California- Santa Barbara reported.
The study found that between 4.8 million and 12.7 million metric tons of plastic waste is dumped into the ocean every year. This is one to three orders of magnitude greater than how much plastic has been reported to be present in the oceans. This study is the first time scientists have quantified the worldwide amount entering the ocean from land.
"Using the average density of uncompacted plastic waste, 8 million metric tons - the midpoint of our estimate - would cover an area 34 times the size of Manhattan ankle-deep in plastic waste," said co-author Roland Geyer, an associate professor at UCSB's Bren School of Environmental Science & Management. "Eight million metric tons is a vast amount of material by any measure. It is how much plastic was produced worldwide in 1961."
The study showed all countries with coastal borders (192 in all) release plastic into the world's oceans, but the 20 top contributors accounted for a whopping 83 percent of the waste. The researchers noted that by reducing the release of this waste by 50 percent these countries could decrease inputs of plastic into the ocean by 40 percent.
"Large-scale removal of plastic marine debris is not going to be cost-effective and quite likely simply unfeasible," Geyer said. "This means that we need to prevent plastic from entering the oceans in the first place through better waste management, more reuse and recycling, better product design and material substitution."
The researchers suggested a number of "achievable solutions" to the global oceanic waste problem such as waste reduction and "downstream" waste management strategies including expanded recovery systems.
"Industrialized countries can take immediate action by reducing waste and curbing the growth of single-use plastic," the researchers stated.
The findings were published in a recent edition of the journal Science.
