Rapid Assessment of Floating Macroplastic Transport in the Rhine

Paul Vriend,Remco Pikaar,Tim Van Emmerik,Caroline Van Calcar,Harm Landman,Merel Kooi

doi:10.3389/fmars.2020.00010

Abstract

Most marine litter pollution is assumed to originate from land-based sources, entering the marine environment through rivers. To better understand and quantify the risk that plastic pollution poses on aquatic ecosystems, and to develop effective prevention and mitigation methods, a better understanding of riverine plastic transport is needed. To achieve this, quantification of riverine plastic transport is crucial. Here, we demonstrate how established methods can be combined to provide a rapid and cost-effective characterization and quantification of floating macroplastic transport in the River Rhine We combine visual observations with passive sampling to arrive at a first-order estimate of macroplastic transport, both in number (10 - 75 items per hour) and mass per unit of time (1.3 – 9.7 kg per day). Additionally, our assessment gives insight in the most abundant macroplastic polymer types the downstream reach of the River Rhine. Furthermore, we explore the spatial and temporal variation of plastic transport within the river, and discuss the benefits and drawbacks of current sampling methods. Finally, we present an outlook for future monitoring of major rivers, including several suggestions on how to expand the rapid assessment presented in this paper.

Highlights

Global plastic production has increased exponentially over the last decades and is expected to further increase (Thompson et al, 2004; Geyer et al, 2017)
We present a rapid assessment of macroplastics in rivers, which combines passive sampling and visual observations
We collected plastic data through visual observations and passive sampling, which will be discussed in more detail

Summary

Introduction

Global plastic production has increased exponentially over the last decades and is expected to further increase (Thompson et al, 2004; Geyer et al, 2017). Besides ethical and esthetic concerns, plastic potentially has negative effects on human livelihood and organisms in aquatic environments (Derraik, 2002; Gall and Thompson, 2015; Wilcox et al, 2015; Koelmans et al, 2017; O Conchubhair et al, 2019). Recent modeling efforts suggest that 1.15– 2.41 million tonnes of plastic waste enters the oceans via rivers annually (Lebreton et al, 2017). Improving such modeling estimates requires field data for calibration, but data on macroplastic transport remains scarce

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Conclusion