According to a scientific estimate, almost 80,000 metric tons of plastic has built up in an area often referred to as the "Great Pacific Garbage Patch." That figure is up to 16 times higher than previously reported, researchers said.
The study, carried out by an international team of scientists alongside The Ocean Cleanup Foundation, utilized two aircraft surveys and 30 vessels to cross the debris field. The three-year mapping effort showed plastic pollution in the world's oceans is "increasing exponentially" since measurements began in 1970.
"We were surprised by the amount of large plastic objects we encountered," Julia Reisser, chief scientist of the study, said in a statement. "We used to think most of the debris consists of small fragments, but this new analysis shines a new light on the scope of the debris."
The patch is not a solid mass of plastic. Nonetheless, it includes 1.8 trillion pieces of plastic and its weight is thought to be the equivalent of 500 jumbo jets.
Of the estimated 1.8 trillion pieces of plastic, microplastics — small plastic pieces less than 5 millimeters long — accounted for about 8 percent of the total trash afloat an area of 1.6 million square kilometers.
The study's use of boats and aerial surveys could help to explain why the latest estimates are much higher than in the past. Nonetheless, rapidly increasing levels of plastic pollution in recent years is also likely to be a significant factor.
On Wednesday, the Foresight Future of the Sea Report forecast the amount of plastic in the world's oceans could be set to triple over the next decade unless litter is curbed.