AUTHOR=Kerpen Nils B. , Schlurmann Torsten , Schendel Alexander , Gundlach Jannek , Marquard Daniel , Hüpgen Markus 

TITLE=Wave-Induced Distribution of Microplastic in the Surf Zone

JOURNAL=Frontiers in Marine Science

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2020.590565

DOI=10.3389/fmars.2020.590565

ISSN=2296-7745

ABSTRACT=<p>In this study, the wave-induced distribution of 13 microplastic (MP) samples of different size, shape, and density was investigated in a wave flume with a sandy mobile beach bed profile. The particle parameter were chosen based on an occurrence probability investigated from the field. MP abundances were analyzed in cross-shore and vertical direction of the test area after over 40,000 regular waves. It was found, that MP particles accumulated in more shallow waters with increasing size and density. Particles with high density (<inline-formula><mml:math id="M1" xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>ρ</mml:mi></mml:mrow><mml:mrow><mml:mi>s</mml:mi></mml:mrow></mml:msub><mml:mo>&gt;</mml:mo><mml:mn>1</mml:mn><mml:mo>.</mml:mo><mml:mn>25</mml:mn><mml:mtext> </mml:mtext><mml:mi>g</mml:mi><mml:mo>/</mml:mo><mml:mi>c</mml:mi><mml:msup><mml:mrow><mml:mi>m</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msup></mml:math></inline-formula>) have been partly confined into deeper layers of the sloping beach during the formation of the bed profile. Particles with a density lower than that of water used in the experiments floated constantly in the surf zone or deposited on the beach caused by wave run-up. A correlation was found between the settling velocity of the MP particles and the flow velocity at the accumulation point and a power function equation developed. The obtained results were critically discussed with findings from the field and further laboratory studies.</p>