News

A new study published in Frontiers in Marine Science estimates that there is more than 14 million metric tons of microplastics on the ocean floor. Microplastics are tiny fragments of plastic, smaller than five millimeters (0.19 inches), that result when plastic trash in the sea deteriorates and breaks down.

The authors of the study, from Australia’s national science agency CSIRO, used a robotic submarine to collect samples of sediments up to 10,000 feet deep from half a dozen sites in the Great Australian Bight, between 180 and 220 miles off the southern coastline of mainland Australia. The researchers found an average of 1.26 pieces of microplastic per gram of sediment from 51 samples. The data was then scaled up to obtain a global estimate of 14.4 million metric tons. Given that the sampling location is remote and far from urban population centers, the researchers say that’s a conservative estimate.

The number pales in comparison to the amount of plastic that scientists believe is now floating in our oceans—some 150 million metric tons. The World Economic Forum has estimated that around eight million tons of plastics enter our oceans every year.