Seafloor microplastic hotspots controlled by deep-sea currents
May 4, 2020
An international research project has revealed the highest levels of microplastic ever recorded on the ocean floor, with up to 1.9 million pieces in a thin layer covering just one square meter. Over 10 million tons of plastic waste enters the oceans each year. Floating plastic waste at sea has piqued the public interest, yet such accumulations account for less than one per cent of the plastic that enters the world’s oceans. The missing 99 per cent is instead thought to occur in the deep ocean, but until now it has been unclear where it actually ended up.
Now published in the journal Science, the research conducted by University of Manchester (UK), National Oceanography Centre (UK), University of Bremen (Germany), IFREMER (France) and Durham University (UK) showed how deep-sea currents act as conveyor belts, transporting tiny plastic fragments and fibers across the seafloor.
These currents can concentrate microplastics within huge sediment accumulations, which they termed ‘microplastic hotspots’. These hotspots appear to be the deep-sea equivalents of the so-called ‘garbage patches’ formed by currents on the ocean surface.
Ian A. Kane, Michael A. Clare, Elda Miramontes, Roy Wogelius, James J. Rothwell, Pierre Garreau, Florian Pohl: Seafloor microplastic hotspots controlled by deep-sea circulation. Science 2020. DOI: 10.1126/science.aba5899