Introduction to Macroplastic Pollution Monitoring
About this Course
Plastic waste in rivers kills and injures animals and plants, damages vessels and infrastructure, and is the largest source of microplastics. Rivers do not simply carry plastic to the sea: much of it is retained along riverbanks, in vegetation such as water hyacinth, and in sediments, where it can stay for years. Reliable monitoring is therefore essential to establish baseline levels of pollution, identify hotspots, prioritise and evaluate interventions, and follow trends over time.
This course introduces the practical monitoring of macroplastic pollution in rivers. It gives an overview of the available methods – visual counting, net and riverbank sampling, drones, cameras and artificial intelligence, acoustic sensing and citizen science – with their advantages and limitations. Two low-cost, widely used methods are covered in detail: visual counting of floating plastic from bridges, and riverbank sampling. Examples from the Rhine and Meuse in Europe, the Saigon and Mekong rivers in Asia, and the Odaw river in Ghana show how these methods are applied in different settings.
The course combines lectures with hands-on work. In a tutorial, participants use real visual counting data from the Meuse (Netherlands), Odaw (Ghana) and Ciliwung (Indonesia) rivers to calculate plastic transport and compare observation-based estimates with a model of plastic emission. A field practical guides participants in collecting and analysing their own visual counting and riverbank data. In the final assignment, participants apply a step-by-step workflow, aligned with the UNEP plastic monitoring guidelines, to design a river plastic monitoring strategy for a Nile Basin country.
What you will learn
- Why river plastic monitoring matters, and the role of rivers as plastic reservoirs
- The main methods for monitoring floating and riverbank macroplastics, and how to choose between them
- How to carry out visual counting and riverbank sampling, and calculate plastic transport and riverbank plastic density from the observations
- How to compare observation-based and model-based estimates of plastic emission
- How to design a monitoring strategy based on goals, river characteristics and available resources
Course content
- Monitoring methods – lecture on visual counting and riverbank sampling
- Tutorial – calculating river plastic transport from visual counting data
- Fieldwork – practical instructions and datasheets for collecting and analysing field data
- Monitoring strategy design – designing a river plastic monitoring strategy for a Nile Basin country
Requirements
No prior knowledge of plastic monitoring is required. A general background in water resources or water quality is helpful. The tutorial and field practical use Microsoft Excel (or similar spreadsheet software), so basic spreadsheet skills are recommended.
Acknowledgements
The course material was developed by Tim H.M. van Emmerik and Louise Schreyers (Wageningen University, the Netherlands), Sabrina Kirschke (Museum für Naturkunde, Germany) and Christian Schmidt (UFZ, Leipzig, Germany).