Microplastics (MP) including tire wear particles (TWP) are omnipresent in marine environments. Mass-based data, transport and effects in the marine air/sea interface, covering also the sea surface microlayer (SML), are rarely investigated. The SML is an ubiquitously occurring, mainly organic film thinner than 1 mm suspected to accumulate MP. Air, SML and underlying water (ULW, 1 m depth) were sampled simultaneously with a remote-controlled research catamaran in areas with varying anthropogenic impact (urban, industrial and rural). MP identification and quantification were conducted with pyrolysis-gas chromatography-mass spectrometry based on polymer specific backbone-related clusters, indicated by the prefix "C" including amongst others polyethylene-terephthalate (C-PET), polymethyl methacrylate (C-PMMA) and TWP. All air and water samples contained MP. C-PET and clusters of polycarbonate (C-PC) were dominant in the air (max. 50 ng MP m^-3). Water samples (max. 11 µg MP L^-1) showed mainly C-PMMA, TWP and C-PET. Clusters of polyethylene, polypropylene, C-PET and TWP accumulated in the SML, while C-PMMA and C-PC dominated the ULW.  MP occurrences were related to anthropogenic influence. Mass loads in urban and industrial areas exceeded the rural ones. No evident enrichment of MP in the SML was observed. Vertical distribution in the air/sea interface was based on both density and polymer sources. The main entry of TWP into the marine environment probably occurs via surface runoff, while C-PET is entrained through atmospheric transport. Ship traffic might contribute to C-PMMA pollution.

Primary Presenter: Isabel Goßmann, Carl von Ossietzky University of Oldenburg (isabel.gossmann@uni-oldenburg.de)

Authors:

Isabel Goßmann, University of Oldenburg, Institute for Chemistry and Biology of the Marine Environment (ICBM)  (isabel.gossmann@uni-oldenburg.de)

Karin Mattsson, University of Gothenburg, Department of Marine Sciences  (karin.mattsson@gu.se)

Martin Hassellöv, University of Gothenburg, Department of Marine Sciences  (martin.hassellov@gu.se)

Claudio Crazzolara, Technische Universität Berlin, Chair of Environmental Chemistry and Air Research  (crazzolara@campus.tu-berlin.de)

Andreas Held, Technische Universität Berlin, Chair of Environmental Chemistry and Air Research  (held@tu-berlin.de)

Tiera-Brandy Robinson, GEOMAR Helmholtz Center for Ocean Research  (brobinson@geomar.de)

Oliver Wurl, University of Oldenburg, Center for Marine Sensors, Institute for Chemistry and Biology of the Marine Environment (ICBM)  (oliver.wurl@uni-oldenburg.de)

Barbara Scholz-Böttcher, University of Oldenburg, Institute for Chemistry and Biology of the Marine Environment (ICBM)  (bsb@icbm.de)