Rhine pours toxic litter into North Sea, study finds

Researchers, assisted by citizen scientists, report the Rhine carries up to 4,700 tonnes of macrolitter a year into the North Sea and that many items contain heavy metals, microplastics or chemical additives; the team says further research is needed.

Researchers at the University of Bonn report that large amounts of litter move down the Rhine and into the North Sea. The team worked with citizen scientists to collect and log rubbish between November 2022 and November 2023. They focused on macrolitter, defined in the study as pieces larger than 25 mm, and monitored material captured by a floating trap anchored in Cologne. The study notes some items contain heavy metals, microplastics and other chemical additives that can affect ecosystems. Key findings: - The research estimates the Rhine carries up to 4,700 tonnes of macrolitter into the North Sea each year. - The monitoring period ran from November 2022 to November 2023 and relied on citizen scientists to collect, transport and record litter data. - A floating trap in Cologne collected almost 2,000 kg of material; 15% of that captured material was plastic and 28% was food- or drink-related. - The report highlights that items such as tyres and treated wood can contain heavy metals or other additives that may affect aquatic life and infrastructure. Summary: The study identifies the Rhine as a significant pathway for macrolitter entering the North Sea and notes the composition is similar to findings from other European rivers. The authors say the findings point to potential environmental and infrastructure effects and call for further research to clarify the full extent and implications.