0
Article Tier 2 Detection Methods Human Health Effects Marine & Wildlife Sign in to save

Microplastics Transport and Mixing Mechanisms in the Nearshore Region

Coastal Engineering Proceedings 2020 26 citations

AI summary Read the abstract

This study investigated how waves and nearshore currents mix and transport microplastics in coastal zones, finding that physical oceanographic processes strongly control where microplastics accumulate along shorelines. Understanding nearshore microplastic transport is important for predicting contamination hotspots and designing effective beach cleanup strategies.

Polymers

Microplastics (MP) are emerging pollutants in the marine environment with potential ecotoxicological effects on littoral and coastal ecosystems. A dominate contributing source of microplastic particles is the fragmentation of macroplastics from manufactured goods, alongside laundered synthetic material, abrasion of vehicle tyres and personal care products. The indiscriminate use of plastic and poor management of plastic waste pose serious threat to ecosystem functionality and resilience. Understanding the key underlying transport and mixing mechanisms which influence the behavior of microplastics and their environmental fate are crucial for identify potential microplastic fate-transport pathways from source to sink. This is fundamental for evaluating microplastic interactions and impact on ecosystems. This paper presents laboratory-based tracer measurements for solute and polyethylene (PE) microplastics in the presence of waves. The tests were undertaken in a wave tank equipped with an active absorption paddle-type wave-maker. Fluorescent dye was used to stain the PE particles using a novel staining technique. Rhodamine dye was used as a proxy for the transport of solute pollutants. The temporal and spatial behavior of both microplastics and solute across the nearshore zone was measured using submersible fiber optic fluorometers. Hydrodynamic conditions were designed to create monochromatic waves with a range of wave steepness Sop = 2 - 5 percent. Tracer measurements were conducted at three locations, seaward of the breaker region, breaker region and inner surf zone to provide a comprehensive understanding of mixing across the nearshore. The dispersion coefficients were determined for both solute and PE particles. The results indicate the dominant role of surface and bed generated turbulence in determining mixing and dispersion influenced by wave breaker type and width of the surf zone. The comparison of tracer data suggests that PE particles, with similar density to water, and the solute tracer have a similar transport and mixing behavior under the influence of waves.

More Papers Like This

Article Tier 2

Numerical modelling of the transport of microplastics in a wind-wave flume

AI summary Read the abstract

A combination of wave flume experiments and numerical modeling was used to track how microplastics move through nearshore waters under wave and wind conditions. The study found that wave-driven processes significantly affect the transport and deposition of microplastics in coastal zones, which act as both sources and sinks for ocean plastic. Improved models incorporating wave dynamics are needed to accurately predict where coastal microplastics end up.

Article Tier 2

Experimental investigation on the nearshore transport of buoyant microplastic particles

AI summary Read the abstract

Researchers measured nearshore transport of buoyant microplastic particles and found they travel at near-fluid velocity before wave breaking but accelerate in the surf zone, with lighter particles transported faster, and developed an empirical formula for predicting cross-shore microplastic transport velocities.

Article Tier 2

A laboratory experiment on the effect of waves on the transport and dispersion of macro, meso, and microplastics in the surf zone

AI summary Read the abstract

This laboratory wave tank experiment examined how waves in the surf zone transport and spread macro-, meso-, and microplastics. Waves caused rapid horizontal and vertical mixing of plastic particles, suggesting that coastal wave action significantly influences where plastic debris concentrates along shorelines.

Article Tier 2

Selective accumulation of plastic debris at the breaking wave area of coastal waters

AI summary Read the abstract

Plastic debris was found to selectively accumulate in the breaking wave zone at the coastline, rather than being evenly distributed across nearshore water. This wave-driven concentration effect has implications for beach cleanup strategies and for understanding how plastic enters and exits nearshore environments.

Article Tier 2

Short-term buoyant microplastic transport patterns driven by wave evolution, breaking, and orbital motion in coast

AI summary Read the abstract

This study used laboratory wave-tank experiments to examine short-term buoyant microplastic transport driven by wave evolution, breaking, and orbital motion in coastal zones, finding that wave dynamics play a significant role in nearshore microplastic distribution.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper