Abstract
Abstract. Understanding and estimating the distribution and transport of microplastics in marine environments has been recognized as a major global research issue. Most of the existing research on transport modelling has focused on low-density particles floating in surface waters, using a 2-D Lagrangian approach and ignoring the vertical displacement of particles. In this work, we evaluate to what extent the vertical movement of particles within surface waters by mixing processes may affect the horizontal transport and fate of microplastics. The aim is to determine whether a 2-D approach is sufficient for the accurate modelling of neustic-microplastics transport or whether a 3-D approach is necessary. For this purpose, we compare visually and statistically the microplastics transport patterns of three simulations in a coastal system: one using a 2-D approach; and two using a 3-D approach with weak and strong vertical turbulence, respectively. The 2-D simulation roughly reproduced the transport and accumulation patterns, but accurate results required a 3-D approach. This was particularly important for strong vertical turbulence and regions characterized by strong vertical current shear. Moreover, a 2-D approach can lead to errors in the results even with negligible turbulence due to simplifications in the velocity field. A 3-D modelling approach is therefore key to an accurate estimation and prediction of microplastics distribution in coastal systems and consequently for planning mitigation and cleaning programmes.
Highlights
Marine plastic debris is of increasing concern because of its persistence, toxicological properties, and effects on marine ecosystems, wildlife, and humans (Lithner et al, 2011; Rochman et al, 2013)
Microplastics pollution has been documented throughout the world and marine habitats (Eriksen et al, 2014; Galgani et al, 2015), in the surface and subsurface water column, on the sea floor, along coastlines and in the polar regions
Numerous studies have used Lagrangian particle-tracking models to assess the sources, pathways and sinks of microplastics in marine environments, especially at ocean and regional scales (e.g. Wakata and Sugimori, 1990; Isobe et al, 2009; Ebbesmeyer et al, 2012; Lebreton et al, 2012; Critchell and Lambrechts, 2016; Carlson et al, 2017; Liubartseva et al, 2018). These models typically consider particles moving in surface waters and use a two-dimensional approach based on surface or vertically averaged current velocities
Summary
Marine plastic debris is of increasing concern because of its persistence, toxicological properties, and effects on marine ecosystems, wildlife, and humans (Lithner et al, 2011; Rochman et al, 2013). Understanding, estimating and predicting the distribution and transport of microplastics is a key step in addressing this global issue. This is a complex problem that requires in situ observations and numerical modelling. Wakata and Sugimori, 1990; Isobe et al, 2009; Ebbesmeyer et al, 2012; Lebreton et al, 2012; Critchell and Lambrechts, 2016; Carlson et al, 2017; Liubartseva et al, 2018) These models typically consider particles moving in surface waters and use a two-dimensional approach based on surface or vertically averaged current velocities.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
