Editorial: Contributions to river plastic monitoring across scales, volume II

Abstract

Plastic pollution in aquatic environments has emerged as a critical global issue, with rivers playing a significant role in transporting plastic debris from land to sea. The complexity of riverine plastic transport is influenced by various factors, including the physical properties of plastics such as type, size, shape, and density, which affect their spatiotemporal distribution in flowing waters (Range et al., 2023). Rivers, however, not only act as conduits for plastic debris but also serve as temporary or perpetual sinks, particularly in tidal zones or compounded stretches, also contributing to the formation of localized accumulation zones (van Emmerik et al., 2022; Liro et al., 2022). These riverine plastic hotspots, while smaller in scale compared to oceanic counterparts, exhibit significantly higher concentrations of plastic, posing risks to ecosystem functioning and human health (e.g., Liro et al., 2022; Tasseron et al., 2024).

Monitoring and quantifying plastic transport in rivers is essential for understanding the dynamics of plastic emissions and validating global estimates (Vriend et al., 2020). Despite advancements in detection technologies, such as deep learning and acoustic methods, challenges remain in achieving continuous and accurate monitoring data and in method harmonization (van Emmerik et al., 2023). New techniques like using the Acoustic Doppler Current Profiler (ADCP) for macroplastic detection (Boon et al.) and instance segmentation models using deep learning architectures like YOLOv8 (e.g., Ahmed et al., 2023; Fan et al., 2024; Kataoka et al.) are being developed to enhance detection capabilities and provide more reliable data. An important step was made towards harmonization of data evaluation and determination of plastic transport (Pessenlehner et al.). These innovations are important in order to create simplified application possibilities and thus improve global datasets and their interpretation. The urgency of addressing plastic pollution is underscored by its detrimental impacts on ecosystems and human health, necessitating comprehensive research and effective policy measures. Plastic debris can lead to ingestion, entanglement, and suffocation of marine life, and its presence in the food chain poses severe health risks to humans, including exposure to toxic chemicals (e.g., Issac and Kandasubramanian, 2021). Global efforts, including the UN’s push for a legally binding treaty (March et al., 2024; UNEP, 2024) and the EU’s ban on single-use plastics, highlight the need for coordinated action to mitigate these impacts (European Commission, 2022; IISD, 2022).