The Plastic Pirates published a new study in the journal Science of the Total Environment. The schoolchildren participating in the project have discovered rivers in which a lot of microplastics (plastic particles smaller than 5 mm) have been found. The investigation shows also shows that the citizen science approach with schoolchildren is very valuable to conduct these large-scale studies. The article is available as an open access publication here: https://www.sciencedirect.com/science/article/pii/S004896972102920X