The project aims to reduce the amount of plastic litter entering the Baltic Sea through rivers and to investigate methods to reuse or recycle the collected litter. The core activities include the development and testing of a monitoring system to record the pollution status of different river compartments, as well as the assessment of the main types of litter, temporal trends, and the pathways by which they enter the rivers. A spatial analysis will identify the main sources of pollution. Based on these findings, effective strategies and best practice examples will be developed together with stakeholders and end users to reduce plastic waste pollution.The project is funded with more than 2 million euros in total by Interreg South Baltic with funds from the European Regional Development Fund, aiming to unlock the potentials of the South Baltic’s blue and green growth through cross-border cooperation between local and regional actors from Denmark, Germany, Lithuania, Poland and Sweden.