Effects of hydrodynamics on the cross‐sectional distribution and transport of plastic in an urban coastal river

Abstract

The mechanisms of plastic transport in rivers remain an important knowledge gap in global plastic pollution research and management. We investigated how river flows and plastics' properties affect transport with a five‐point cross‐sectional field study in the Hillsborough River in Tampa (Florida, USA) using a 500‐µm Neuston net and an Acoustic Doppler Current Profiler. We conducted in‐depth analysis of water velocity profiles as well as plastics' concentrations and properties, determining advective, vertical, and lateral transport fluxes. Under calm flow conditions, advective fluxes were two orders of magnitude higher than lateral and vertical fluxes. Under turbulent conditions, enhanced particle exchange in the cross‐section resulted in a three to tenfold increase in lateral and vertical plastic fluxes. The impact of turbulence on plastic particles depended on properties such as size, shape, and composition. This study presents a unique assessment of flow conditions driving plastic pollution in an urban coastal river setting. Practitioners points Multipoint, cross‐sectional sampling and onsite flow profile collection should be adopted as a common practice for plastic field data collection to reduce uncertainty. Varying flow conditions affect the drivers of plastic transport in rivers. Advective surface fluxes govern plastic transport under calm flow conditions, while turbulent flow conditions enhance cross‐sectional mixing and particle exchange. Larger and more irregular‐shaped plastics are more affected by turbulence.

Effects of Urban Hydrology on Plastic Transport in a Subtropical River

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Microplastic and microfiber fluxes in the Seine River: Flood events versus dry periods

“…For this reason, high water levels may significantly increase the plastic load in freshwater. (2018), but are one or two orders of magnitude higher than other estimations (Haberstroh et al, 2021;Kataoka et al, 2019). These estimations may indicate significant plastic inputs from the Greater Paris region.…”

A Field Guide for Monitoring Riverine Macroplastic Entrapment in Water Hyacinths

“…Given that flow velocity and tidal dynamics could also influence macroplastic flux and plastic cross-sectional concentrations (Haberstroh et al, 2021;van Calcar and van Emmerik, 2019), these were also characterized during the field campaign. Ultimately, flow velocity is a key metric to understand transport dynamics in rivers, including plastic debris movements.…”