Plastic waste taints the ocean floors

Billions of tiny plastic fragments are littering each square kilometre of the deep sea, an analysis of sea-floor sediments suggests1. Although the study sampled a small number of sites, the locations ranged from the subpolar Atlantic to the Indian Ocean, enabling researchers to design future studies that could determine where much of the plastic manufactured by humans ends up.

Plastic waste has long been recognized as a problem for the oceans: it pollutes beaches; accumulates in floating, nation-sized ‘garbage patches’; and is consumed by seabirds, fish and other creatures. In a study published last week2, scientists estimated that more than 250,000 tonnes of plastic litter the ocean’s surface.

Yet that is only a minuscule fraction of the plastic produced each year, says Richard Thompson, a marine biologist at Plymouth University, UK. Slightly less than half of the material ends up recycled or in landfills, according to some studies, and much of the rest goes ‘missing’, he notes (see ‘Fate of ocean plastic remains a mystery’).