Millions of Tonnes of Nanoplastics Are Polluting the Ocean

Researchers have discovered 27 million tonnes of nanoplastics distributed across just the top layer of the temperate to subtropical North Atlantic Ocean. The team sampled water at three depths across 12 locations during a November 2020 research cruise, finding average concentrations of 18 milligrams per cubic meter of three plastic types: polyethylene terephthalate, polystyrene and polyvinylchloride.

These particles, smaller than one micrometer in diameter, behave differently from larger microplastics by remaining suspended throughout the water column rather than settling to the ocean floor. The nanoplastics can pass through cell walls and enter the marine food web through phytoplankton, said Tony Walker, an environmental scientist at Dalhousie University. The world’s oceans contain an estimated 3 million tonnes of floating plastic pollution when excluding nanoplastics.