Plastic is the most pervasive pollutant in the ocean today. But researchers have struggled to estimate just how much of the 6 billion tons of plastic that has been manufactured since the mid-20th century ultimately winds up in the ocean.
Now a carefully vetted estimate of our oceans’ plastic burden shows that the answer is not pretty. Based on the calculations, at least 5.25 trillion pieces of plastic—weighing nearly 269,000 tons—are currently bobbing around in the ocean. A team of researchers from six countries reported the finding today in PLOS ONE.