This session welcomes contributions from field, laboratory and modelling studies that aim to advance our understanding of river network and catchment-scale plastic transport and accumulation processes. We are soliciting studies dedicated to all plastic sizes (macro, micro, nano) and across all geographic settings. We are especially encouraging studies that can link plastic accumulation and transport to catchment-wide hydrological, ecological or geomorphological processes that we can better understand where, when and why plastics accumulation takes place in aquatic-terrestrial environments.
In this session, we explore the current state of knowledge and activities on macro-, micro- and nanoplastics in freshwater systems, focusing on aspects such as:
• Transport processes of plastics at catchment scale;
• Source to sink investigations, considering quantities and distribution across environmental matrices (water and sediment) and compartments (water surface layer, water column, ice, riverbed, and riverbanks);
• Plastic in rivers, lakes, urban water systems, floodplains, estuaries, freshwater biota;
• Effects of hydrological extremes, e.g. accumulation of plastics during droughts, and short-term export during floods in the catchment;
• Modelling approaches for global river output estimations;
• Legislative/regulatory efforts, such as monitoring programs and measures against plastic pollution in freshwater systems.
Anthropogenic macrolitter (ML) in rivers affects ecosystems and human health. A custom-built, interception-based litter trap (LT) passively collected ML in the Rhine River, one of Europe’s largest river watersheds, continuously, over a one year-long sampling period. The LT, anchored in Cologne, captures floating ML >4.24 cm without disturbing shipping traffic. This location covers 90% of the rivers total length, including the rivers tributaries. By systematically covering the discharge range of an entire year that did not included extreme floods, the dataset, with information on ML composition and sources, was correlated with five environmental factors. Plastics made up the largest share of ML among all 10 monitored material types, which may affect water quality. The detailed monitoring revealed 145 EU Marine Strategy Framework Directive ML list (MSFD list) categories in the Rhine. Untraceable items account for 36.0% of the total ML, with fragments making up 30.6%. The sources of 64.0% of ML were identified, with private consumers responsible for the largest share (56.0%) of land-based ML. Single-use items contribute 40.4%. Based on the continuous data, discharge and precipitation affect riverine ML numbers. A linear extrapolation scenario estimates that around 53,000 ML items are transported in the Rhine at Cologne every day.
How to cite: Höreth, K., Gnann, N., Schweigert, N., Evers, M., Ternes, T. A., and Hamann, L.: A Continuous Approach to Macrolitter Monitoring in Large River Systems: Identifying Sources, Drivers, and Quantities, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13102, https://doi.org/10.5194/egusphere-egu25-13102, 2025.
Pollution of the marine environment by plastic is an ever-growing problem. One mayor source of coceanic plastic are rivers and other waterways, and their pollution has an influence on riverine and marine environments.
The Ocean Cleanup aims to reduce this harm by, among other things, closing the tap. To be able to tackle this task, it is important to know when and where the plastic is entering the oceans, so that targeted and efficient action can be taken. A crucial step therefore is understanding the drivers of riverine plastic transport on a global scale. We approach this problem with a global probabilistic river model.
Previous iterations relied on discharge to scale the in-river transport. Studies have since indicated that discharge might not be a good predictor of plastic transport for a wide range of rivers. Thus, the latest version now includes the influence of velocity by using terrain slope as a proxy, which allows us to investigate its influence on a global and local scale.
First results show that including slope in the formulation impacts the seasonal variation of the calculated plastic transport. The most interesting difference, however, is how different types of rivers contribute to the total emissions. So is the relative influence of large and shallow catchments decreased compared to results of the previous model, while the relative contribution of steep catchments increased.
This tool will later be finetuned by comparing it to the analysis of a large-scale drifter field study along the Amazon, Mekong and Motagua Rivers. With this we strive to gain more detailed insight into this complex topic.
How to cite: Ebner, R., Mani, T., and Lebreton, L.: The influence of velocity on plastic transport in rivers – Improving a global river model to map riverine plastic emissions into the marine environment , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17210, https://doi.org/10.5194/egusphere-egu25-17210, 2025.
The world’s future is threatened by a triple planetary crisis of climate change, biodiversity loss and pollution. Plastic pollution is linked to various consequences for biota and is a major concern for policy makers. Since the 1970s the widespread presence of industrial plastic pellets, with dimensions between 25 and 50 mm, have been observed in surface waters and beaches all over the world, raising concerns about the potential environmental impacts of plastic pellets .
We present a case study along the Scheldt estuary, encompassing the port of Antwerp, a large polymer hub for production, handling and distribution of plastic pellets. Beginning decades ago, pellets are being unintentionally released into the environment and find their way to the Scheldt river, where plastic transportation and accumulation on the riverbanks are determined by the physicochemical properties of the pellets (polymer type, density, size, shape, …) as well as hydrological processes and other factors, e.g. surface morphology, vegetation,… . Efforts have been made to quantify plastic pollution in the Scheldt estuary. However there is a paucity of data to evaluate plastic pellet pollution in particular and there is no harmonized sampling methodology that is suitable for measuring pellet concentrations on the estuary’s riverbanks, with its great spatial and temporal diversity in occurrence and heterogeneity in landscape.
To elucidate transport and accumulation patterns of the released plastic pellets, we set up an extensive monitoring campaign. Pellets were manually sampled on 28 locations along the Scheldt riverbank between Vlissingen and Melle, using a 50 by 50 cm quadrat. To capture the spatial heterogeneity of the pellet concentration, at each location 9 replicates were taken in a standardized manner. The surface materials within the quadrats were collected and air dried before pellets were separated manually and counted.
The spatial distribution of the number of pellets on the riverbanks revealed that most pellets were found in the Antwerp port area (3,352 pellets per m²). Upstream from the port (314 pellets per m²) more pellets were found compared to the locations downstream from the port (110 pellets per m²). Significantly more pellets were found on locations close to a physical barrier (e.g. a bridge, a quay, an unnatural bulge, …), located in the outer bend or on a straight part of the river, oriented in Southern, Western or Southwestern wind direction, with a surface other than flat sandy and on locations with high or very high vegetation.
Fourier-transform infrared spectroscopy was used to determine the polymer type of the pellets, revealing that most pellets consisted of polyethylene and polypropylene. The images obtained by stereomicroscopy, confocal microscopy and scanning electron microscopy revealed changes in colour and breakdown of the surface of pellets.
Insights into the magnitude and spatial distribution of plastic pellet pollution on the Scheldt riverbanks provide an estimate of the transportation patterns of the port of Antwerp’s plastic pellets. The easy sampling methodology provides opportunities to scale up or standardize monitoring campaigns, also in a non-marine environment, which could improve the knowledge about plastic pellet occurrence and its potential ecological risk worldwide.
How to cite: Diels, H., Town, R. M., and Blust, R.: Transport and Accumulation of Plastic Pellets along the Scheldt Estuary between Vlissingen (Netherlands) and Melle (Belgium), EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10667, https://doi.org/10.5194/egusphere-egu25-10667, 2025.
Plastic litter accumulating in riverine riparian habitats is a global concern. Macrolitter items are highly visible (items > 0.5 cm) and threaten river and riparian biodiversity and ecosystem services. Although scientific interest in plastic entrapment along river corridors is growing, large-scale studies and predictive models assessing drivers and patterns in riverine plastic accumulation are still lacking. Given those gaps, this study investigates plastic entrapment by riparian vegetation at different spatial scales and ecological gradients across European rivers. We focused on six river basins across Europe, covering the biogeographic regions boreal (Sweden), continental (Germany), alpine (Trento, Italy), Mediterranean (Rome, Italy), and Atlantic (Northern Spain, Northern Portugal) climatic regions as part of the European Biodiversa+ RIPARIANET project. By surveying macrolitter across six European basins, we aim to unveil differences in riverine macrolitter accumulation in riparian areas across a large biogeographic and land-use gradient. We found that riparian vegetation acts as a sink for macrolitter across European rivers, with the highest trapping value in the Tiber catchment (Italy) and the lowest in the Sävar River basin (Sweden), following a clear latitudinal gradient. Among predictors, urbanization, land use, river discharge, sinuosity, and vegetation structure are crucial factors driving macroplastic accumulation. Our findings shed light on how macroplastics accumulate in riparian zones across Europe, with both ecological and societal consequences, and could guide management efforts for their active removal. Given the potential impacts on biodiversity and ecosystem resilience, our results may help prioritize monitoring and clean-up activities of plastics to protect and restore riparian ecosystems.
How to cite: Gallitelli, L., Bruno, M. C., Barquin, J., Concostrina Zubiri, L., Jonsson, M., Hughes, M., Larsen, S., Laux, M., Pace, G., Scalici, M., and Schulz, R.: Plastic entrapment by riparian vegetation across ecological gradients in European rivers: First insights from the RIPARIANET Project , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1025, https://doi.org/10.5194/egusphere-egu25-1025, 2025.
The late 20th century witnessed a sharp proliferation in the construction of dams and in-stream barriers to address the rising global demands for urban supply, energy, and food production. Nowadays, around 16% of all global annual river discharge is regulated by approximately 58,700 large dams (>3 hm3 storage capacity) with a global storage capacity of 7,000-8,300 km3. While essential for food security and socioeconomic development, dams impose significant trade-offs by fragmenting river systems, disrupting fluvial regimes, trapping sediments and altering water quality in impounded areas. In the last decade, plastic pollution in freshwater and marine environments has garnered growing scientific attention. While extensive research has been conducted in riverine and marine environments, studies on plastic contamination in reservoir-dam systems remains scarce due to the logistical and hydrological complexities involved in the study of these systems. This work aims to provide insights into the influence of reservoir-dam systems and their operational regime on the fate of plastic pollution. We propose a conceptual model of the dynamics and hydrosedimentary processes of micro- and macroplastics within hydropower, water supply and flood control reservoirs. This is complemented with a comprehensive review of 43 research articles focused on microplastic pollution in reservoirs published between 2015 and 2024 covering up to 62 large reservoir-dam systems worldwide with an average storage capacity of 3.2 hm3, of which 62% belong to cascading dam schemes. The meta-analysis evidenced the pervasiveness of plastic pollution. Microplastics were detected in water and sediments from all studies, including the impounded regions and the upstream and downstream sections of the reservoirs. Microplastics concentration within the set of reservoirs exhibits considerable heterogeneity, with preliminary values ranging from very low to highly polluted levels (3 to 87,000 MPs/m³ in water and 20-20,070 MPs/kg in sediments). Such values are highly conditioned by land use, topography, seasonal rainfall patterns and sampling periods and the different settling rates of microplastics among others. The concentration of plastics decreases by several orders of magnitude downstream of dams in a significant proportion of case studies (65%), particularly in cascading dam systems, suggesting that reservoirs act primarily as key sinks for plastics due to their low-energy hydrodynamics. This is highly relevant for the formulation of transport models estimating plastic input to the ocean. However, growing evidence indicates that water management operations can significantly accelerate the transport of plastics towards downstream regions. Water discharge and sediment flushing operations can release substantial quantities of low-density plastics and microfibers downstream, thereby accelerating their flux to estuaries. Similarly, reservoirs that convey water directly to purification plants, irrigation canals or pumping stations can contribute to the removal of plastics from the fluvial system. These findings are particularly important for understanding the role of reservoir regulation in mediating plastic transport from inland water systems to the ocean, as well as for developing more effective strategies to mitigate microplastic contamination.
How to cite: Vélez-Nicolás, M., van Emmerik, T., Sánchez-Guerrero-Hernández, M. J., and Stibora, M.: The role of dams as sources and sinks of plastics in global rivers, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16251, https://doi.org/10.5194/egusphere-egu25-16251, 2025.
Plastic contamination has been receiving considerable attention during the last few decades (Siegfried et al., 2017). In the present study, the authors extended process-based eco-hydrology models, NICE (National Integrated Catchment-based Eco-hydrology) and NICE-BGC (BioGeochemical Cycle) (Nakayama, 2017), to link them with plastic debris model (Nakayama and Osako, 2023a, 2023b), and applied to all of the 109 first-class (class A) river basins throughout Japan. The model included advection, dispersion, diffusion, settling, dissolution and deterioration due to light and temperature, interaction with suspended matter (heteroaggregation), resuspension, and biofouling. These processes could help to evaluate effect of mismanaged plastic waste (MPW) and point sources (tyres, personal care products, dust, and laundry) on spatio-temporal dynamics of macro- and micro-plastics there. The result clarified the finer resolution slightly decreased the flux of macro-plastics, particularly in the urban regions. The model also revealed that the amount of micro-plastic flux calculated by accumulating point information at sewage treatment plants could be replaced by analysis using grid data categorized for treatment methods (sewage, septic tank, untreated) in each grid instead of global data of per capita emission and treatment rates (Jones et al., 2021). The result also clarified that the plastic cycle, particularly micro-plastic, in rivers flowing through urban areas has been significantly altered (Wagner et al., 2019). Finaly, the author evaluated the method to improve plastic cycle in urban regions towards understanding of urban plastic cycle with fewer inventory data (Strokal et al., 2021). These results help to quantify impacts of plastic waste on biosphere in urban systems, and may aid development of solutions and measures to reduce plastic input to the ocean.
References
Jones, E.R., et al. 2021. Earth System Science Data, 13, 237-254, doi:10.5194/essd-13-237-2021.
Nakayama, T. 2017. Journal of Geophysical Research: Biogeosciences, 122, 966-988, doi:10.1002/2016JG003743.
Nakayama, T., Osako, M. 2023a. Ecological Modelling, 476, 110243, doi:10.1016/j.ecolmodel.2022.110243.
Nakayama, T., Osako, M. 2023b. Global and Planetary Change, 221, 104037, doi:10.1016/j.gloplacha.2023.104037.
Siegfried, M., et al. 2017. Water Research, 127, 249-257, doi:10.1016/j.watres.2017.10.011.
Strokal, M., et al. 2021. Urban Sustainability, 1, 24, doi:10.1038/s42949-021-00026-w.
Wagner, S., et al. 2019. Environmental Science & Technology, 53, 10082-10091, doi:10.1021/acs.est.9b03048.
How to cite: Nakayama, T.: Towards improving the accuracy of plastic cycle in urban regions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7481, https://doi.org/10.5194/egusphere-egu25-7481, 2025.
Rivers play an important role in the global distribution of plastic pollution. Plastics are both retained within river systems, and emitted into the ocean. The net transport of plastic from rivers into the sea is determined by the transport processes within the estuary, which connect the freshwater and marine environments. Estuarine plastic transport and retention dynamics are the combined effect of tidal dynamics, freshwater discharge, and river morphology. Despite its crucial position within the global plastic budget, the effect of estuaries on plastic transport from rivers into the ocean remain unresolved. In this presentation, we provide an overview of estuarine plastic transport and retention dynamics across rivers in Europe and Asia. We extended a simple method [1] to estimate the net transport per tidal cycle, based on surface plastic observations, plastic concentration measurements, and modelled river discharge. Net plastic transport varies strongly with considered time scale, ranging from a single tidal cycle to a full year. Furthermore, we show net transport is impacted by the strength of the tidal dynamics, freshwater discharge, level of plastic pollution, and other river characteristics. Our results demonstrate across timescales, only a limited portion of river plastic pollution may exported into the ocean. The remainder is hypothesized to accumulate on riverbanks, in vegetation, and at other elements within the riverscape [2]. During spring tides and limited freshwater discharge, the net plastic export can be negative, transporting more items from the sea into the estuary. These findings are in line with recent observational evidence of high plastic retention in rivers, and limited net transport from rivers into the sea [3]. This presentation aims to contribute to a better understanding of the global plastic flows from land to sea. Through better understanding the effect of estuaries on river plastic transport, we aim to contribute to improved monitoring, quantifying, and reduction of plastic pollution in the environment.
References
[1] Schreyers, L.J., et al. "River plastic transport affected by tidal dynamics." Hydrology and Earth System Sciences 28.3 (2024): 589-610.
[2] van Emmerik, T.H.M., et al. "Rivers as plastic reservoirs." Frontiers in Water 3 (2022): 786936.
[3] Lotcheris, R.A., et al. "Plastic does not simply flow into the sea: River transport dynamics affected by tides and floating plants." Environmental Pollution 345 (2024): 123524.
How to cite: van Emmerik, T., Zweers, E., González-Fernández, D., and Tas, S.: The effect of estuaries on plastic transport from river into the sea, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11917, https://doi.org/10.5194/egusphere-egu25-11917, 2025.
Background: Microplastic contamination in freshwater lakes has grown up to a main concern in recent years. While there is no knowledge about the global distribution and loads of microplastics in the lacustrine environment. Methods: We commence to solve this matter based on trawl net method investigations in freshwater lakes. Through redundant analysis (RDA) and structural equation model (SEM), we first identify the main influencing factors that affect the microplastic concentrations in freshwater lakes. Then, we use Machine Learning and number to mass transformation tactics to fill in gaps and reach a global prediction (Fig. 1). Findings: (1) We found cropland plays a similar positive effect with population density on microplastic concentration, while vegetation has the opposite effect. The findings highlight the importance of these land use types in the lake basin for the first time. (2) Totally, we demonstrate an average microplastic concentration of 0.57 items/m3 in lakes and reservoirs around the world. The accumulated microplastic load in the upper 20 m of lakes and reservoirs is 10,167 tons, which is equal to 508 million plastic bottles. (3) The concentration hotspots of lacustrine microplastics gather in east and southeast Asia, India, north back of Black Sea and Nile Delta. North America, Africa and Asia are continents with highest microplastic loads (Fig. 2), but with different causation (concentration-dependent and/or area-dependent, shape composition affected). The giant lakes around world contribute highest microplastic loads. Significance: The findings of this study provide a feasible approach to estimate the microplastic loads of global lakes, and assist to make reasonable policies to mitigate the microplastic pollution in freshwaters.
Fig. 1 Research framework of how to make global estimation of microplastic loads in lakes/reservoirs.
Fig. 2 The predicted microplastic loads in lakes worldwide (lake area>100 km2). The red dotted lines are boundary lines of continents in the present study.
How to cite: Dong, H., Wang, X., zhang, R., Gong, P., Zeng, J., Niu, X., and Yin, Q.: Microplastic Loads in Freshwater Lakes: Prioritized Regions and Management Strategies, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4182, https://doi.org/10.5194/egusphere-egu25-4182, 2025.
Plastic pollution is considered a global environmental challenge, prompting international regulation efforts such as the UN plastic treaty, a global initiative aimed at addressing the escalating plastic pollution crisis. Rivers with high connectivity to urban areas are particularly exposed to macroplastic pollution. Floods amplify macroplastic abundance in rivers by mobilizing previously deposited, and introducing new macroplastics. Recent observations suggest most of the flood-driven macroplastic transport is either exported downstream or stored within rivers. Yet, a comprehensive understanding of the fate of these mobilised macroplastics remains unresolved.
We assessed flood impact on macroplastic deposition along river floodplains, using data from fifteen events — five floods and ten non-flood conditions — across two Dutch rivers (the IJssel and Meuse). We quantified riverbank macroplastic concentrations under both non-flood and flood conditions, and floodplain macroplastic concentrations under flood conditions. Non-flood conditions were defined as events with return periods below bankfull discharge, while floods exceeded this threshold (1.5-year return period). We estimated riverbank macroplastic concentrations following five floods of varying magnitudes, with return periods ranging from 2 to 100 years. We attributed macroplastic concentrations to the main drivers of macroplastic deposition, using a parsimonious modelling approach. We considered ten factors, including river and floodplain characteristics, and proximity to potential macroplastic sources. Similar to sediment and large wood deposition, the longitudinal distribution of macroplastic along floodplains is likely influenced by the balance between supply and deposition factors, which determines floodplain capacity in storing macroplastics.
We found that higher flood return periods increased macroplastic deposition, with the two largest floods depositing two to three times more macroplastic than non-flood conditions. In addition, deposition mechanisms varied by flood type. Obstruction-based deposition dominated during an extreme summer flood (summer 2021 in the Meuse), when macroplastics mainly accumulated in inundated trees. Low-energy deposition prevailed during a long winter flood (winter 2024 in the IJssel), with high macroplastic concentrations found in wide floodplain sections where flow velocities decreased.
The identified typologies in floodplain macroplastic deposition patterns suggest varying spatial distribution patterns within the floodplains. These can help to develop interventions to reduce the floodplain macroplastic legacy. Due to its parsimonious nature, our modeling approach can be applied to other rivers and flood events. We anticipate that this may contribute to better understanding of the impact of floods on plastic pollution.
How to cite: Schreyers, L., Hauk, R., Wallerstein, N., Teuling, A. J., Uijlenhoet, R., van der Ploeg, M., and van Emmerik, T.: Flood type drives river-scale macroplastic deposition, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18363, https://doi.org/10.5194/egusphere-egu25-18363, 2025.
Recent studies have investigated the effects of hydrological conditions on the dynamics of microplastics (MPs) in rivers. However, no clear correlation is consistently observed. In addition, these studies focus on sampling before and after the event, neglecting the dynamics of MPs over the course of the event. Given the increased intensity of extreme events related to climate change, an understanding of fine temporal MP dynamics in rivers is required to better estimate the fluxes and their contribution to downstream contamination. To address this gap and enhance understanding of the impact of hydrological conditions on MP contamination, an intensive sampling campaign was conducted throughout hurricane Kirk. This event caused an extreme flood in October 2024 at the outlet of a small peri-urban catchment (Avenelles, 45 km², 70 km east of Paris). Sampling was performed using a plastic-free in-situ filtration pumping system coupled with in series filtration (300 and 10 µm). Analyses were carried out using Fourier transform infrared µ-spectroscopy (automated imaging and data processing with SiMPle software), enabling the characterization of MP particles down to 25 µm. In addition, total suspended solids (TSS) were characterized alongside the sampling campaign to investigate their potential role in the transport and dynamics of MPs. Throughout this campaign, 18 samples were collected throughout the 6-day flood event, including pre-event conditions, the increasing and decreasing water levels, and post-event base flow. The MP concentrations and flux increased twofold from pre-flood (669 MPs m-3 and 398 MPs s-1) to flood peak (10804 MPs m-3 and 56181 MPs s-1). Four days after the flood peak, the concentration and flux returned to levels similar to those observed pre-flood (977 MPs m-3 and 479 MPs s-1). In addition, the concentrations of MPs and TSS exhibited a similar trend, with a correlation coefficient of 0.66. These results highlight the limitations of interpreting hydrological effects based on data limited to pre- and post-flood sampling, underscoring the importance of studying the full progression of flood dynamics.
How to cite: Friceau, L., Calabro Souza, G., Blanchouin, A., Hénine, H., Tassin, B., and Dris, R.: Microplastic dynamics along an extreme flood event in a peri-urban stream , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10593, https://doi.org/10.5194/egusphere-egu25-10593, 2025.
The rapid growth in plastic production and mismanagement of plastic waste streams have raised environmental concerns, with microplastics (MPs) emerging as pervasive pollutants. This study quantifies stormwater MP exports from urban areas by examining five stormwater management ponds (SWPs) and their representative catchments in Kitchener, Ontario, Canada, using field sampling, laboratory extraction, and modeling approaches. Using Laser Direct Infrared (LDIR) spectroscopy, MP concentrations were determined for different MP shapes and polymer compositions, enabling the calculation of both particle- and mass-based fluxes. A hydrology model coupled with a mass balance approach was employed to estimate MP emission factors (i.e. export coefficients) and retention efficiencies in both particle- and mass-based units. Land use impacts were examined by classifying stormwater catchments through machine learning-aided analysis of aerial imagery. Sediment emissions were also quantified through surveys and samplings to explore potential correlations with MP exports. Industrial catchments showed the highest MP emission factor at 8.7×1011 particles ha-1 year-1 (19.6 kg ha-1 year-1), whereas residential areas exhibited the lowest emissions at 1.7×1011 particles ha-1 year-1 (2.3 kg ha-1 year-1). Fibrous MPs accounted for 2–6% of particle-based emissions but 10–24% by mass, highlighting differences in composition across land use types. Parking lots and traffic were key contributors to MP pollution, consistent with polymer composition analysis. SWP retention efficiencies ranged from 73–97% for total loads but varied for specific polymers, from minimal to complete retention. Retention performance was influenced by SWP design features such as inlet and outlet configurations, catchment wash-off dynamics, and hydraulic residence time. These findings emphasize the critical role of land use and SWP design in urban stormwater MP mitigation, with industrial and high-traffic areas contributing significantly to pollution. Understanding these dynamics provides actionable insights for mitigating MP emissions and optimizing SWP retention performance to protect aquatic ecosystems.
How to cite: Reshadi, M. A. M., Rezanezhad, F., Kaykhosravi, S., Nguyen, T. H., Slowinski, S., Shahvaran, A. R., Alcott, L., Puopolo, M., and Van Cappellen, P.: Microplastic Emissions and Retention in Urban Catchments and Stormwater Ponds, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4437, https://doi.org/10.5194/egusphere-egu25-4437, 2025.
Microplastics are increasingly recognized as potential tracers of anthropogenic activities and sediment transport. Due to their irregular shapes and low densities, these particles exhibit transport behaviours that differ significantly from naturally occurring sediments. However, analysing their distribution and characteristics can help identify microplastic sources and sinks, offering insights into their transport dynamics within the environment. This study focuses on the Thayatal/Podyjí National Park, situated along the border of Lower Austria (Austria, AT) and Southern Moravia (Czech Republic, CZ), where plastic pollution has not previously been monitored. Water samples (approximately 5 m³ each) were collected in triplicate from five locations along and across a hydrologically disconnected section of the Thaya/Podyjí River, spanning from Vranov (CZ) to Hnanice (CZ). Sampling was conducted using a 30 cm in diameter plankton net with a mesh size of 150 μm in early November 2024. Flow velocity was measured across the width of the channel using MF Pro flowmeter. Between each sampling phase, the net was cleaned three times using pressurized filtered (40 µm) water at 3-4 bars. To assess the influence of tributaries and their connectivity to the main river channel, samples were also taken from three tributaries: Klaperův Creek (CZ), Kaja Creek (AT), and the Fugnitz River (AT). Additional samples were collected along the Fugnitz River, a medium-sized agricultural stream (catchment area 131 km2) that has been the focus of connectivity research over the past decade. This study is conducted alongside ongoing research on microplastic transport at the catchment scale, with a particular emphasis on lateral connectivity in the Fugnitz catchment. The overarching aim of this research is to evaluate the potential of microplastics as tracers of geomorphological connectivity and to improve understanding of their behaviour in comparison to natural sediments. This analysis is supported by erosion modelling and grain size analysis. Geomorphological features of the Thaya/Podyjí River, along with anthropogenic factors influencing connectivity, are being analysed using remote sensing and GIS tools. In the sedimentology laboratory, water samples from the Thaya/Podyjí section undergo organic matter reduction using Fenton’s reagent (H₂O₂ with an Fe²⁺ catalyst) and density separation with potassium formate (HCO2K; density 1.45 g/cm³). Microplastic particles are then analysed with an ATR-FTIR Lumos II microscope, with manual identification performed on 25% of the filter area. Ongoing protocol validation includes blank tests and recovery rate analyses to ensure methodological reliability. As of now, results from 3 locations along the main channel were produced. From upstream to downstream, location 1 had 6.4±1.31 particles per m3, location 2 had 10.2±0.8 particles per m3 and location 3 had 10±3.39 particles per m3. In the upcoming spring, additional fieldwork may be performed to evaluate seasonality of discharge as well as other sampling parameters affecting the discharge i.e. depth and time of sampling.
How to cite: Roudbar, S., Young, R., Pöppl, R., Le Heron, D., and Wagreich, M.: A transboundary case of investigating longitudinal water and sediment connectivity using microplastics in the Thayatal/Podyji National Park, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6718, https://doi.org/10.5194/egusphere-egu25-6718, 2025.
The Seine River basin, home to a quarter of the French population, faces the generation of around one million tons of plastic waste each year in the Paris region. Despite efficient plastic waste management, some of it escapes the systems and ends up in the Seine River, contributing to its pollution. Recent studies show that plastic debris remains in the river due to tides. This promotes the accumulation of plastic debris on the riverbanks, particularly during floods, creating historical accumulation zones in some areas. In this way, these plastics along with their chemical substances, pollute all environmental compartments. The aim of the TEDiPLAST project is to better understand the sources, stocks, fluxes, and dynamics of plastic debris in historical accumulation zones. How they build up and what do they become? First, innovative clean-up techniques will be tested to ensure effective collection of plastic debris, including those as small as preproduction industrial pellets. Second, adapted sampling and treatment protocols will be implemented to obtain representative results along a size class continuum, from macroplastics to coarse microplastics (> 500 µm), while considering their respective characteristics. Third, macroplastics will be sorted according to the OSPAR/TSG ML, whereas smaller plastic debris will be analysed by ATR-FTIR. Additionally, all data related to tracing debris sources and their lifespan in the environment will be recorded (dates, brand names, logos, etc.). One of the challenges consists in combining analytical techniques and sampling protocols to cover a large continuum of plastic sizes, while remaining representative of extensive and heterogeneous accumulation zones where up to 4 kg of plastic per square meter accumulates. Furthermore, preproduction industrial pellets will also be a focus, as they are one of the main plastic wastes found in these zones due to the vicinity of some producers and converters along the Seine River. At the end, remediation scenarios will be suggested to support mitigation policies and strategies.
How to cite: Vadaine, C., Tassin, B., Dris, R., and Tramoy, R.: From historical plastic pollution to environmental remediation scenarios. A case study in the Seine estuary , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7379, https://doi.org/10.5194/egusphere-egu25-7379, 2025.
Global plastic production in 2023 reached 400.3 million metric tons (MMT)1. After being released into the environment, plastics degrade into secondary plastic – a major source of microplastics due to environmental factors. Microplastics (MPs), defined as plastic particles smaller than 5 mm, are ubiquitous across marine, freshwater and atmospheric environments2. Given their widespread dissemination and persistence, MPs have emerged as a notable environmental threat. Vietnam would rank 4th of the top 20 countries most polluted by plastic waste, with approximately 3.1 MMT of mismanaged plastic waste discharged in 20223. Despite this, research on MPs within the Association of Southeast Asian Nations (ASEAN) remains limited, accounting for only 5% of global studies, with Vietnam’s contribution of just 0.6%3.
This work aimed to examine the occurrence of MPs in superficial sediment samples collected at the 3 largest Vietnamese rivers from downstream parts to the sea: the Red River (RR, n=25 sampling points), Saigon River (SG, n=16), and Mekong River (MK, n=13) during the rainy season 2024. The analytical procedure involved digestion by hydroperoxide 20% (v/v), flotation by potassium carbonate (d=1.5 g.cm-3), and filtration (pore size 13 to 5000 µm). The filters were analyzed by µ-FTIR to determine the abundances and composition.
The results showed the concentrations of MPs in sediments ranged from 653 to 8069 items.kg in RR, from 2978 to 32151items.kg-1 in SG, and from 3173 to 15216 items.kg-1 dry weight in MK. The results underlined the previously observed link between MP input and vicinity to urban/densely populated areas since the highest concentrations were found close to the urban areas along the three rivers (i.e. Hanoi, Ho Chi Minh City, and Can Tho City). As expected, the trend showed MP dilution at the rivers’ mouths. The particle size of 13–200 µm represented the major size class, accounting for 72.4%, 90.7%, and 85.1% in RR, SG, and MK, respectively. Polyethylene, polypropylene, polyethylene terephthalate, and polyvinyl chloride (PVC) were the major polymers, accounting for a total of 82.4%, 78.3%, and 87.5% in RR, SG, and MK, respectively. The risk was assessed and represented high degrees of pollution load index, hazard index, and potential ecological risk index. High ecological risks were primarily linked to polymer hazards, particularly PVC, rather than pollution load. All the stations presenting a high polymeric risk also posed a high potential ecotoxicological risk. However, the station containing a large number of MPs does not necessarily present the highest potential ecological risk. This must be carefully considered in future regulations. The outcomes of this study will contribute todocumenting the quality status of the aquatic environment and support improved management and conservation of aquatic resources not only in Vietnam but also in ASEAN countries, where plastic production, consumption, and recycling activities are rapidly increasing.
References
[1] PlasticsEurope, 2023
[2] Sambandam et al., 2022, https://doi.org/10.1016/j.chemosphere.2022.135135
[3] Gabisa et al., 2022, https://doi.org/10.1016/j.marpolbul.2022.114118
How to cite: Nguyen, T. T., Bui, V. H., Fauvelle, V., Ouillon, S., Wong-Wah-Chung, P., and Malleret, L.: Abundances and characteristics of sedimentary microplastics in the three main Vietnamese Rivers, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9806, https://doi.org/10.5194/egusphere-egu25-9806, 2025.
Rivers store and transport large amounts of macroplastic and other macrolitter, and floods potentially drive their transport and deposition processes. Floods can have a major impact on the mobilization of plastic, yet factors determining the deposition remain unresolved. In this study, we sampled floodplains along two major Dutch rivers, following two flood events of different magnitude: the July 2021 extreme flood along the Meuse (> 100 year return period) and the January 2024 winter flood along the IJssel (3 year return period). Post-flood macroplastic and other macrolitter is found to locally accumulate in vegetation elements and debris piles, however it is not clear what this looks like at a river scale. We therefore decided to sample floodplains very detailed to analyze these deposition dynamics. We documented the specific location on the floodplain, and the element, e.g. debris pile or type of vegetation, in which each macrolitter item was found. Overall macrolitter accumulated mainly in vegetation elements along the Meuse river and within debris piles along the IJssel river. The average macrolitter concentration was lowest in grass (0.12 - 0.13 items/m²) and highest in debris piles (5.67 – 12.70 items/m²) for both rivers. There seem to be two ways macrolitter items are generally deposited on inundated riverbanks, above ground, and on the ground. Above ground, they can encounter an obstruction in their transport path and get entangled, e.g. in inundated tree branches, on the ground, they can be deposited where water and land surface meet, e.g. be left behind at the highest floodline. Macrolitter items deposited above ground in shrubs and trees, were larger compared to items deposited on the ground and in ground-covering vegetation. Macrolitter deposition following the flood in the Meuse showed distinct obstruction based deposition where the flood was most severe. Overall, along the Meuse, the items had a higher average mass and a higher mass concentration with 3.49 g/m², compared to the IJssel with 1.72 g/m². Deposition along the IJssel was debris pile dominated, with 69% of items deposited in debris < 2.5 cm. Debris piles along the IJssel constituted 2.2% of the sampled area but contained 58.3% of found macrolitter items and 32.3% of macrolitter mass. Identifying such hotspots and understanding how different floods drive the transport and deposition of macrolitter can contribute to guide improvements on monitoring and post-flood clean-up strategies, as well as prevention strategies, and impact assessment.
How to cite: Hauk, R., Schreyers, L. J., van der Ploeg, M., Teuling, A. J., Wallerstein, N., and van Emmerik, T. H. M.: Post-flood macroplastic deposition in riparian vegetation and floodplains, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9892, https://doi.org/10.5194/egusphere-egu25-9892, 2025.
A novel transport model of macro-plastics in rivers is applied to the River Meuse (Netherlands) to estimate yearly outflow quantities towards the North Sea, and to predict locations where waste accumulations along the banks and in the floodplain are likely to occur. The model has been calibrated to measurements of plastic concentrations in the flow, thereby giving a realistic indicative value of yearly plastic budgets. A comparison to aerial images of plastic waste hotspots observed after a recent flood event shows that the model is capable of predicting approximate waste accumulation sites. We explain how the model could be applied to other river cases around the world and, next, argue how the model can be used to make monitoring campaigns more effective, and how it can help in the design of effective clean-up strategies.
How to cite: Huthoff, F., De Lange, S., and Gensen, M.: Modelling yearly accumulation and outflow budgets of macro-plastics on a river basin scale, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10640, https://doi.org/10.5194/egusphere-egu25-10640, 2025.
Plastics are part of our daily life. As a result, macro- and microplastics are found in many rivers and seas worldwide. Microplastics often originate in water systems from personal care products, household dust, laundry, and car tire wear. Macroplastics such as bottles, litter, and plastic bags are not often managed properly, resulting in water systems. Macroplastics can also be the secondary source of microplastics in waters, which may even increase pollution levels. It becomes more difficult to stop the use of plastics in our activities despite some promising efforts (e.g., the increased availability of reusable products). In addition, with ongoing urbanization, more plastics are expected in the waters. Furthermore, plastics have connections to more than five Sustainable Development Goals (SDGs) such as food security (SDG2; e.g., plastic mulching as a pollution source), sustainable sanitation (SDG6; e.g., better treatment leading to less microplastics in waters from sewage), sustainable cities (SDG11; e.g., more microplastics from car tire wear and sewage), responsible consumptions (SDG12; e.g. control waste generation) and climate change (SDG13; e.g., more floods leading to more plastics in waters), etc. This opens opportunities to explore sustainable strategies to reduce plastics in rivers and seas to increase the benefits for other SDGs. In this study, we model the effects of sustainable strategies on reducing future macro- and microplastics in rivers and seas in the 21st century under the urbanization trends. For this, we use the MARINA-Plastics model, developed and evaluated in our earlier studies1-3. Here, we integrate insights on the effects of the combined sewage connections and treatment and their individual effects on microplastic reductions in rivers up to 2100 worldwide1-2. For seas, we utilize the insights of the sustainable strategies for both macro- and microplastics in the future3. For rivers, our results for microplastic reduction differ over time worldwide. By 2030, the model suggests that controlling waste generation (e.g., less use of microplastics in personal care products) may be more effective in reducing microplastics than better sanitation (more sewage connections plus better wastewater treatment). In contrast, better sanitation seems more effective in reducing microplastic pollution by 2100. For seas globally, microplastics are expected to double by 2100 in an unsustainable scenario with increased urbanization. This pollution is projected to be reduced to below the level of 2010 when assuming the implementation of sustainable strategies such as better treatment. For macroplastics, increases are somewhat projected between 2010 and 2100 in an unsustainable scenario whereas large reductions are projected in a sustainable scenario by 2100. In all our scenarios, many European, North American, and Asian rivers were pollution hotspots in 2010, mainly due to microplastics. In an urbanizing future, many African rivers may become new plastic pollution hotspots mainly as a result of both microplastics (from urbanization activities) and macroplastics (from increasing waste production). Sustainable strategies for these hotspots should be combined to reduce plastic pollution. These insights could support SDGs.
1: Ayeri et al., (2024) 10.1021/acs.est.4c07730
2: Guo et al., (2024) 10.1002/sd.3279
3: Micella et al., (2024) 10.1029/2024EF004712
How to cite: Strokal, M., Bak, M. P., Guo, Y., Ayeri, T., and Micella, I.: Plastics in an urbanizing world: sustainable strategies for rivers and seas, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12102, https://doi.org/10.5194/egusphere-egu25-12102, 2025.
Rivers play a key role in the transport and accumulation of plastic waste in the environment. Given the durability of plastic waste and the continuation of plastic production, the accumulation of plastic in rivers is predicted to continue to increase. The goal of our research is to establish a baseline for micro- and macroplastic pollution in European rivers. To do this, we have developed a new modelling framework to simulate a European, high resolution (3 arc second), spatially probabilistic model for micro- and macroplastic transport.
While previous plastic transport models focus on quantifying plastic export to sea, we hypothesise that most plastic pollution does not reach the river outlet in the short term. This work, therefore, focuses specifically at shifting the emphasis on modelling plastic export to providing a novel outlook on the accumulation of micro- and macroplastic pollution on riverbanks and in the riverbed sediment. Our model uses the latest insights on plastic transport processes, accounting separately for both micro- and macroplastics. The model uses meteorological variables (wind and surface runoff) and land-use variables (land friction and slope) to estimate the transport of plastic from its on-land source to the river system. We use discharge, river width, riverbank friction and the presence of artificial structures, to simulate the transport of plastic in the river. An increase in the availability of plastic measurements in European rivers, allows us to provide a European specific plastic transport model for micro- and macroplastic pollution. Observed micro- and macroplastic export values, including those collected by the European RIMMEL project for floating macroplastic, were used to calibrate the model (González-Fernández et al., 2021). By accounting for the accumulated and transported plastic pollution, our model will provide a revised estimation of the spatial distribution of plastic litter in all European rivers, facilitating the implementation of tailored mitigation measures.
Reference:
González-Fernández, D., Cózar, A., Hanke, G., Viejo, J., Morales-Caselles, C., Bakiu, R., Barceló, D., Bessa, F., Bruge, A., & Cabrera, M. (2021). Floating macrolitter leaked from Europe into the ocean. Nature Sustainability, 4(6), 474-483.
How to cite: Stibora, M., van Emmerik, T. H. M., Waldschläger, K., González-Fernández, D., and Weerts, A.: Establishing a European baseline for plastic accumulation and transport in rivers, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15263, https://doi.org/10.5194/egusphere-egu25-15263, 2025.
Urban areas discharge significant quantities of microplastics (MPs) into the environment. In rivers the flux of MPs is poorly estimated due to metrological and analytical limitations as well as a poor assessment of the hydrodynamic role. These limitations are mainly related to the sampling devices (e.g, net or pumping samplers) which do not allow to produce representative data in spatial and temporal scales, as, the sampling is executed at one specific location in the water column and for short duration. To address these issues, this project proposes to improve current methods for quantifying MPs and understand their dynamics across various river spatio-temporal scales. A passive sampler was adapted for MP studies and the first experiment to be carried out is focusing on assessing spatio-temporal variability in a river located upstream of the Paris metropolitan area. The device will be placed within the water column of the Seine river (France) at different distances from the shore. The samples will a pre-treatment protocol: organic matter digestion and density separation. Analysis will be executed using micro Fourrier Transform Infra-Red. Specially for this project, the uncertainties will be accessed by comparing two different analytical devices (Nicolet - Thermo-Fischer and Spotlight 4000 - Perkin Elmer). In parallel we will quantify and characterise the total suspended solids for all samples. These approaches will give insights in MP dynamics within the water column over a year allowing to provide a fine temporal variation of the MPs flux in the Seine river and its associated uncertainties. Additionally, the aim would be to establish whether total suspended solids could be used as a reliable proxy for following MPs dynamics.
How to cite: Diop, K., Calabro Souza, G., Gasperi, J., Tassin, B., and Dris, R.: Methodological investigations and understanding of the transfer dynamics of microplastics in the River Seine, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16965, https://doi.org/10.5194/egusphere-egu25-16965, 2025.
The transport of objects by water flows, particularly in rivers, plays a critical role in natural and environmental disasters, from the movement of vehicles and large objects during floods to the pervasive distribution of pollutants such as macroplastics or microplastics. Recent studies highlight alarming concentrations of microplastics in freshwater systems and even domestic water sources, posing a significant threat to public health due to potential ingestion and associated health risks for humans and animals. Understanding and mitigating these hazards require advanced mathematical modeling and computational solutions capable of capturing the complexity of transport dynamics and environmental interactions.
This work presents the development and integration of a Lagrangian model to study the spatial and temporal evolution of microplastics transport in water flows. Material elements representing microplastic particles are modeled as discrete entities, whose transport is driven by hydrodynamic forces computed using physical coefficients, i.e. a kinematic approach. The model is driven by an Eulerian framework based on the nonlinear Shallow Water Equations (SWE), which govern the fluid flow dynamics. This approach offers a robust basis to compute flow evolution while providing detailed insights into particle transport mechanisms.
The new Lagrangian Particle Tracking module (LPT) is integrated into the SERGHEI (Simulation Environment for Geomorphology, Hydrodynamics and Ecohydrology in Integrated form) model. SERGHEI facilitates comprehensive investigations into particle dynamics by accounting for key processes such as advection and dispersion, and those unique to microplastic transport such as deposition, flotation, degradation, and biofouling. The microplastic model provides valuable information on the behavior of microplastics in rivers and hydrological regions, which facilitates the identification of possible solutions to reduce their concentrations. The use of a 2D hydrodynamic model offers greater computational efficiency compared to other models based on 3D hydrodynamic approaches. This efficiency is enhanced by the implementation of both microplastic and hydrodynamic models in a high-performance computing (HPC) framework, allowing realistic simulations of complex scenarios. Moreover, the integration of processes specific to microplastic transport ensures realistic time evolution of particle positions. However, further experiments are essential to validate, refine and improve the accuracy of the model. Future work will extend the model to simulate larger debris, including vehicles, waste containers, and boulders, thus broadening its applicability for environmental risk assessment.
How to cite: Vallés, P., Morales-Hernández, M., Caviedes-Voullième, D., Roeber, V., and García-Navarro, P.: A Lagrangian model for microplastics transport in SERGHEI, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17050, https://doi.org/10.5194/egusphere-egu25-17050, 2025.
Estuaries account for 88% of the global coastline and act as filters for water, sediments and particles (Dürr et al. 2011) and may act as important pathways of plastic pollution. Recent studies suggested that rivers can contribute between 1.15 – 2.41 million tons of plastic per year globally (Lebreton et al. 2017) or 307 and 925 million items per year from Europe alone (Gonzalez-Fernández et al. 2021). However, the processes of transport and retention at rivers, estuaries and beaches are still poorly understood. Recent results from Schernewski et al. (2024) showed that floating plastics released at a city harbor at the beginning of the Warnow estuary (Germany) were trapped in reeds or beaches within 6 days, with only 0.4% transported to the Baltic Sea (11 km) during storms, while sinking plastics accumulated near the source during calm winds (7 m/s) but were resuspended and transported up to 4 km away during storms (< 20 m/s). However, this study considered only one emission location and there is still a knowledge gap regarding the role of item size and density, as well as the emission locations from multiple litter sources, and thereby the retention potential at coastlines and seafloor.
In this study, we investigate the emission, transport and retention of plastics in the Warnow estuary, Germany, an exemplary estuary exposed to urban areas, harbor activities, tourism and other land-uses, using a highly resolved 3D hydrodynamic model of 20 m and a Lagrangian particle tracking approach using the Ocean Parcels framework. Emission source locations were defined with GIS. First simulations considered the emission of particles from the tourism and recreation sector over 10-days, with 1000 particles released per point. The results showed for emission sources closer to the estuary opening and the beach, 68% of particles were retained, whereas for particles released at the harbor and urban area (beginning of the estuary), 92% were trapped on beaches or reed belts, with the majority beaching within the first 2 days only 3.5 km away from the source. These results already indicate that the emission of plastics may be overestimated since few studies take into account emission location and retention dynamics.
Building upon these learnings we aim to i) provide a detailed emission budget for different sources of plastics at the Warnow estuary and ii) assess the influence of item size and density in the transport and retention of particles. This high resolution model together with the emission approach shall provide a more comprehensive assessment of emission, transport and accumulation of plastics and contribute to the understanding of the plastic budget at other estuaries as well as for the elaboration of effective mitigation strategies based on specific accumulation hotspots and emission sources.
How to cite: Escobar-Sánchez, G., de Ramos, B., Lange, X., Piehl, S., Haseler, M., and Schernewski, G.: Plastics in estuaries: estimating an emission budget, transport and fate of plastics through high resolution model simulations, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18892, https://doi.org/10.5194/egusphere-egu25-18892, 2025.
The INSPIRE Horizon Europe project aims to combat plastic pollution in rivers by deploying 20 scalable technologies designed to prevent and remove litter. These innovative solutions will be demonstrated across six rivers in Europe. A key component of the project involves monitoring plastic pollution in the rivers and on their banks to establish a baseline and assess the effectiveness of the implemented technologies.
One of the monitoring solutions introduced is a camera- and drone-based system for tracking plastic flux in the rivers and measuring macroplastic densities on riverbanks. The fixed camera system utilizes a series of Commercial Off-The-Shelf (COTS) surveillance cameras, equipped with protective housing and real-time data links. These autonomous cameras covering the full width of the river, continuously upload data to the cloud, providing uninterrupted monitoring. In addition, the drone data in collected along the riverbanks using high-resolution RGB - camera.
Robust machine learning models, including convolutional neural networks (CNNs) and advanced pre-trained foundation models like Segment Anything, are employed for litter detection and characterization. Furthermore, innovative approaches are being explored to transform camera-based plastic detections into plastic flux measurements. These methods leverage feature detection techniques such as Faster R-CNN, pretrained on ImageNet and further fine-tuned for this purpose, combined with feature matching algorithms like ResNet and auxiliary data integration.
The presentation will cover preliminary findings from fixed camera systems installed on Belgium’s Temse Bridge, as well as drone data collected along the Scheldt riverbank (BE) and in the Londenhaven area of the Port of Rotterdam (NL).
How to cite: De Keukelaere, L., Moelans, R., and Van Overloop, A.: Large-scale remote monitoring of riverine litter using drones and bridge-mounted cameras. , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19776, https://doi.org/10.5194/egusphere-egu25-19776, 2025.
Today rivers are known as the primary transport routes for plastic from continental to marine ecosystems. Although plastic pollution in aquatic environments poses a significant environmental threat, impacting both human health and ecosystems, knowledge about the distribution patterns, sources, and transport mechanisms of plastic in rivers remains limited. Through a collaboration between Albanian and Austrian research institutions, significant steps were taken to investigate the origins and pathways of floating and untethered macroplastics in the Ishëm River — one of the most polluted rivers in Europe — and to highlight the extent of plastic pollution in Albanian rivers.
The project’s objectives included implementing a combined measurement approach, utilizing both net-sampling and particle counting, to establish a data-based macroplastic transport assessment and identify major sources of plastic pollution. Additionally, the project focuses on building knowledge for sustainable river cleanup, providing globally relevant insights, and addressing the critical pollution levels in the Ishëm River.
Massive amounts of macroplastics pollute the Ishëm River delta and are carried as far as the Italian coast (over 150 km), as evidenced by labeled debris. Repeated cleanup campaigns by Albanian scientists and numerous stakeholders, collecting up to 400 bags of waste per action, have shown only temporary success, as plastic returns related to active waste disposal into rivers and mobilization after hydrological events. Preventing plastic from entering the river and intercepting it earlier in its course are urgent priorities. The project identified poorly functioning waste management systems and widespread misconceptions — such as the belief that rivers naturally dispose of waste — as key contributors to the pollution. To address these issues, the project developed strategies for long-term improvement, including establishing a lasting cooperation network, capacity-building initiatives, awareness-raising campaigns. Generating scientific data, furthermore, is essential to quantify pollution levels and identify responsibilities by assessing main sources of plastic waste. These efforts contribute to the creation of sustainable recycling programs and set the foundation for transforming the Ishëm River from one of Europe’s most polluted waterways into a restored ecosystem.
How to cite: Pessenlehner, S., Gjyli, L., Selamaj, S., Miri, F., Kolitari, J., Fortuzi, S., and Liedermann, M.: Macroplastics in the Ishëm River: Causes, Impacts, and Strategies for Transforming One of Europe’s Most Polluted Rivers, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21764, https://doi.org/10.5194/egusphere-egu25-21764, 2025.
