Beach scene with swirling winds and waves depositing plastic debris.

Vanishing Coastlines: Can We Win the Fight Against Plastic Pollution?

Kai Mendoza in Climate & Environment August 2025 • 4 min read.

"A New Model Reveals the Complex Dance Between Wind, Tides, and Trash on Our Beaches"

Our oceans are drowning in plastic. From the deepest trenches to the most remote shorelines, plastic pollution has become an undeniable crisis. Macroplastics and microplastics are now ubiquitous, threatening biodiversity and ecosystems worldwide. While the problem is global, the solutions must often be local, starting with understanding how plastic accumulates on our beaches.

For years, scientists have studied the sources, fate, and impact of marine plastics. The Marine Strategy Framework Directive (MSFD) in Europe has pushed Member States to monitor marine litter, including plastics. But despite these efforts, the actual mechanics of litter deposition and transport on our shores remain murky. What truly drives the accumulation—or erosion—of plastic on our beaches?

Now, a new study published in Marine Pollution Bulletin sheds light on this critical question. Instead of relying on broad statistical correlations, researcher W.R. Turrell developed a simple, hypothesis-driven model to simulate how floating marine plastic litter is blown onto a beach and then redistributed by wind and tides. The findings offer valuable insights into beach survey design, litter accumulation rates, and the setting of effective targets to combat plastic pollution.

Unraveling the VaWWL Effect: Wind and Water's Impact on Beach Litter

Beach scene with swirling winds and waves depositing plastic debris.

Turrell's model focuses on the "variable wind and water level effect," or VaWWL. It posits that the interplay between variable wind and water levels is a primary driver of plastic deposition on beaches. The model was configured for a typical "windward" beach—Aberdeen beach in Scotland—characterized by a macro-tidal environment and exposure to the North Sea's dynamic weather patterns. This beach, extending approximately 22 km, faces the prevailing winds.

The model operates with a constant time step, incorporating hourly data for water level, wind speed, and wind direction. These inputs drive the core equation, which calculates the amount of litter blown onto the beach:

Nlitter(t) = Nconstant|(W(t)/Wmax)|sin(Θ(t))

Here, Nlitter(t) represents the amount of litter deposited at time t, Nconstant relates to the background concentration of floating litter, W(t) is the average wind speed, Wmax is the maximum onshore wind speed, and Θ(t) is the angle of wind incidence to the beach. The model further divides the beach into discrete vertical compartments to simulate the rising and falling tides. When winds blow onshore, new litter is deposited in the compartment corresponding to the current water level. Rising water levels sweep up litter from lower compartments, while falling levels leave litter behind. Offshore winds, above a critical speed, remove litter from wet compartments, mimicking the "self-cleaning" effect observed on many beaches.

A Call to Action: Understanding and Combating Beach Litter

Turrell's model, while simple, offers valuable insights into the complex dynamics of beach litter. It highlights the importance of considering the VaWWL effect when designing beach surveys, estimating accumulation rates, and setting realistic targets for litter reduction. By understanding how wind and water interact to deposit and redistribute plastic on our beaches, we can develop more effective strategies to combat this pervasive form of pollution and protect our coastlines for future generations.

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This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1016/j.marpolbul.2018.10.024, Alternate LINK

Title: A Simple Model Of Wind-Blown Tidal Strandlines: How Marine Litter Is Deposited On A Mid-Latitude, Macro-Tidal Shelf Sea Beach

Subject: Pollution

Journal: Marine Pollution Bulletin

Publisher: Elsevier BV

Authors: W.R. Turrell

Published: 2018-12-01

Everything You Need To Know

What is the primary focus of the study regarding plastic pollution on beaches?

The study primarily focuses on understanding the mechanics of litter deposition and transport on beaches. It introduces a model to simulate how floating marine plastic litter is blown onto a beach and then redistributed by wind and tides, emphasizing the importance of understanding these dynamics to combat plastic pollution effectively.

How does the 'variable wind and water level effect' (VaWWL) influence plastic deposition on beaches?

The 'variable wind and water level effect,' or VaWWL, suggests that the interplay between variable wind and water levels is a key driver of plastic deposition on beaches. Onshore winds deposit new litter at the current water level. Rising tides sweep up litter from lower compartments, while falling tides leave litter behind. Offshore winds, if strong enough, can remove litter from wet compartments, creating a self-cleaning effect. This interaction significantly impacts how plastic accumulates and redistributes on shores.

What are the key components used in the model to simulate litter deposition on Aberdeen beach?

The model uses hourly data for water level, wind speed, and wind direction as inputs. It calculates the amount of litter deposited using the equation Nlitter(t) = Nconstant|(W(t)/Wmax)|sin(Θ(t)), where Nlitter(t) is the amount of litter deposited at time t, Nconstant relates to the background concentration of floating litter, W(t) is the average wind speed, Wmax is the maximum onshore wind speed, and Θ(t) is the angle of wind incidence to the beach. It also divides the beach into discrete vertical compartments to simulate the rising and falling tides.

What implications does the model have for designing effective beach surveys and setting targets for litter reduction?

The model highlights the importance of considering the 'variable wind and water level effect' (VaWWL) when designing beach surveys. Understanding how wind and water interact to deposit and redistribute plastic helps in estimating accumulation rates more accurately. This understanding is crucial for setting realistic and effective targets for litter reduction, as it provides insights into the dynamics that influence litter presence on beaches. Factoring in VaWWL leads to more informed and effective strategies in combating plastic pollution.

How might the insights from this study, particularly the 'variable wind and water level effect' (VaWWL), inform broader strategies for combating marine plastic pollution beyond beach cleanups?

Understanding the 'variable wind and water level effect' (VaWWL) allows for a more targeted approach to marine plastic pollution. Knowing how wind and tides influence litter deposition can inform the strategic placement of collection devices in areas where plastic accumulates most. Additionally, the model can help predict seasonal variations in litter deposition, enabling proactive measures. This localized insight, combined with broader initiatives like reducing plastic production and improving waste management, can contribute to a more comprehensive strategy against marine plastic pollution. The Marine Strategy Framework Directive (MSFD) can benefit from incorporating VaWWL insights for more effective monitoring and mitigation efforts.