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Titel |
The vertical distribution of buoyant plastics at sea: an observational study in the North Atlantic Gyre |
VerfasserIn |
J. Reisser, B. Slat, K. Noble, K. du Plessis, M. Epp, M. Proietti, J. de Sonneville, T. Becker, C. Pattiaratchi |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1726-4170
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Digitales Dokument |
URL |
Erschienen |
In: Biogeosciences ; 12, no. 4 ; Nr. 12, no. 4 (2015-02-26), S.1249-1256 |
Datensatznummer |
250117834
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Publikation (Nr.) |
copernicus.org/bg-12-1249-2015.pdf |
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Zusammenfassung |
Millimetre-sized plastics are numerically abundant and widespread across the
world's ocean surface. These buoyant macroscopic particles can be mixed
within the upper water column by turbulent transport. Models indicate
that the largest decrease in their concentration occurs within the first few
metres of water, where in situ observations are very scarce. In order to
investigate the depth profile and physical properties of buoyant plastic
debris, we used a new type of multi-level trawl at 12 sites within the North
Atlantic subtropical gyre to sample from the air–seawater interface to a
depth of 5 m, at 0.5 m intervals. Our results show that plastic
concentrations drop exponentially with water depth, and decay rates decrease
with increasing Beaufort number. Furthermore, smaller pieces presented lower
rise velocities and were more susceptible to vertical transport. This
resulted in higher depth decays of plastic mass concentration (milligrams m−3) than numerical concentration (pieces m−3). Further multi-level
sampling of plastics will improve our ability to predict at-sea plastic load,
size distribution, drifting pattern, and impact on marine species and
habitats. |
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