Plastic waste has long been a visible — and growing — problem in oceans around the world, with refuse littering the shorelines of once-pristine beaches, stretching out across a wide expanse of sea in the Great Pacific Garbage Patch, and threatening sea life that ingest it.
A new report offers a glimpse of one of the impacts below the surface of the ocean: the scale of microplastics building up on the ocean floor. In what researchers called the first such global estimate, Australia’s national science agency says that 9.25 million to 15.87 million tons of microplastics — fragments measuring between five millimeters and one micrometer — are embedded on the sea floor.
That is far more than on the ocean’s surface and it is the equivalent of 18 to 24 shopping bags full of small plastic fragments for every foot of coastline on every continent except for Antarctica.
It is an issue that activists have long warned about even as the fight to clean up the ocean has focused largely on the eradication of single-use plastic products like shopping bags.
The findings were published on Monday in a new study by the Commonwealth Scientific and Industrial Research Organization, or C.S.I.R.O.
“It really points to the ubiquity of the problem. It is really everywhere all the time and increasing,” Britta Denise Hardesty, a principal scientist for C.S.I.R.O. and an author of the study, said in a phone interview on Wednesday.
Microplastics are not confined to the ocean. They are also found in air particles and can be spread by wind. A variety of microplastics was even detected in the human gut.
While cities have banned plastic bags and straws, the use of