The Ocean Is Contaminated by Trillions More Pieces of Plastic Than Thought
Somewhere between 15 trillion and 51 trillion pieces of plastic litter the world’s oceans, a new study has found. That’s three to 10 times more plastic than scientists had previously estimated.
The study, led by climate scientist Erik van Sebille at London’s Imperial College and coauthored by researchers at nonprofit group 5 Gyres, built on the findings of two papers published last year. The scientists tapped every data set on plastic pollution published since the 1970s and ran the numbers through three computer models
The total weight of small plastic pieces that accumulated in 2014 alone is estimated to be between 93,000 and 236,000 metric tons, “which is only approximately one percent of global plastic waste estimated to enter the ocean” annually, the researchers wrote. The study only focused on microplastics (those less than 200 millimeters in size) that could be captured by trawling nets pulled along the ocean surface. Thus, the researchers’ estimates do not count plastic waste that ends up sinking to the ocean floor or that is ingested by fish and other marine species.
Each American throws away as much as 185 pounds of plastic a year. In the last decade, the total weight of plastic products entering the market has risen from 225 million tons in 2004 to 311 million tons in 2014, according to industry group Plastics Europe.
“These estimates are larger than previous global estimates, but vary widely because the scarcity of data in most of the world ocean,” the researchers wrote. Studies estimate that large amounts of plastic go undetected because they sink to the ocean floor or are eaten by fish.
In one study, deep-sea fish in the North Pacific gyre were estimated to have ingested between 12,000 and 24,000 metric tons of microplastics annually.
According to the new study, the wide range in the estimated amount of plastic entering the world’s oceans every year “reveals a fundamental gap in understanding.”
But the data available shows that the North Pacific Ocean, often referred to as the “Great Pacific Garbage Patch,” has the highest density of plastic thanks in part to the region’s circular ocean currents and wind patterns.