ESR3 will investigate the abundance and sources of MP in the Aarhus area, a densely populated area, and model its fate. For this purpose, the ESR will design and conduct a sampling campaign covering potential MP sources (urban infrastructures like sewage systems with combined and separate discharges, WWTPs, industry parks, runoff from roads and agricultural areas, recreation areas) and sinks (harbours, barrages). The identified hotspots and sources will be investigated in a second campaign on a smaller spatial and temporal scale to take a closer look at the complex dispersal patterns. To generate comparable data sets, harmonised methods for the sampling, processing, analysis, and data reporting will be developed with the other involved participants. Biota samples will represent relevant key species (in consultation with limnologists). MP will be extracted from the samples, identified and quantified. Based on the results, sources, and sinks of MP will be identified in the Aarhus area.