A new study, reported in the journal Science, has found that more than 4.8 million metric tons of plastic waste enters the oceans from land each year, and that figure may be as high as 12.7 million metric tons.
Scientists calculated that 275 million metric tons of plastic waste was generated in 192 coastal countries in 2010, with 4.8 to 12.7 million metric tons entering the ocean. This map shows the estimated mass of mismanaged plastic waste from each coastal country; the darker the color, the larger the amount; countries shaded in white were not included. Image credit: University of California, Santa Barbara.
“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 study co-author Dr Roland Geyer of the University of California, Santa Barbara.
“8 million metric tons is a vast amount of material by any measure. It is how much plastic was produced worldwide in 1961.”
Previous studies have documented the impact of plastic debris on more than 660 marine species – from the smallest of zooplankton to the largest whales, including fish destined for the seafood market – but none have quantified the worldwide amount entering the ocean from land.
“This is the first time people have connected the dots in a quantifiable way,” said Jenna Jambeck, the lead author on the study and an environmental engineer at the University of Georgia.
The scientists found that 4.8 to 12.7 million metric tons of plastic entered the ocean in 2010 from people living within 50 km of the coastline.
That year, a total of 275 million metric tons of plastic waste was generated in those 192 coastal countries.
“For the first time, we’re estimating the amount of plastic that enters the oceans in a given year. Nobody has had a good sense of the size of that problem until now,” said study co-author Prof Kara Lavender Law from the Massachusetts-based Sea Education Association.
Knowing how much plastic is going into the ocean is just one part of the puzzle.
Millions of metric tons reach the oceans, yet researchers are finding between 6,350 and 245,000 metric tons floating on the surface – a mere fraction of the total.
This discrepancy is the subject of ongoing research.
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Jenna R. Jambeck et al. 2015. Plastic waste inputs from land into the ocean. Science, vol. 347, no. 6223, pp. 768-771; doi: 10.1126/science.1260352
