Seafloor microplastic hotspots controlled by deep-sea circulation
|Author(s)||Kane Ian A.1, Clare Michael A.2, Miramontes Elda3, 4, Wogelius Roy1, Rothwell James J.5, Garreau Pierre6, Pohl Florian7|
|Affiliation(s)||1 : School of Earth and Environmental Sciences, University of Manchester, Manchester M13 9PL, UK.
2 : National Oceanography Centre, University of Southampton Waterfront Campus, Southampton SO14 3ZH, UK.
3 : Faculty of Geosciences, University of Bremen, 28359 Bremen, Germany.
4 : MARUM-Center for Marine Environmental Sciences, University of Bremen, 28359 Bremen, Germany.
5 : Department of Geography, University of Manchester, Manchester M13 9PL, UK.
6 : IFREMER, Univ. Brest, CNRS UMR 6523, IRD, Laboratoire d’Océanographie Physique et Spatiale (LOPS), IUEM, 29280, Plouzané, France.
7 : Department of Earth Sciences, Durham University, Durham DH1 3LE, UK.
|Source||Science (0036-8075) (American Association for the Advancement of Science (AAAS)), 2020-06 , Vol. 368 , N. 6495 , P. 1140-1145|
|WOS© Times Cited||289|
Although microplastics are known to pervade the global seafloor, the processes that control their dispersal and concentration in the deep sea remain largely unknown. Here, we show that thermohaline-driven currents, which build extensive seafloor sediment accumulations, can control the distribution of microplastics and create hotspots with the highest concentrations reported for any seafloor setting (190 pieces per 50 grams). Previous studies propose that microplastics are transported to the seafloor by vertical settling from surface accumulations; here, we demonstrate that the spatial distribution and ultimate fate of microplastics are strongly controlled by near-bed thermohaline currents (bottom currents). These currents are known to supply oxygen and nutrients to deep-sea benthos, suggesting that deep-sea biodiversity hotspots are also likely to be microplastic hotspots.