Microplastics in the water column of the Rhine River near Basel: 22 months of sampling
Description
Data generated for the publication titled "Microplastics in the water column of the Rhine River near Basel: 22 months of sampling". Abstract Measured microplastic concentrations in river surface waters fluctuate greatly. This variability is affected by season, and is co-driven by factors, such as sampling methodologies, sampling site, or sampling position within site. Unfortunately, most studies comprise single-instance measurements, whereas extended sampling periods are better suited to assess the relevance of such factors. Moreover, microplastic concentrations in riverine water column remain underexplored. Similar to the oceans however, this compartment likely holds significant amounts of microplastics. By representatively sampling the entire Rhine River cross-section near Basel through five sampling points over 22 months, we show that microplastic (50–3000 µm) concentration in the water column was not well explained by river discharge. This suggests a chemodynamic export regime, in which occasional high discharge events, as observed here, can nonetheless over short time periods lead to peak microplastic concentrations (highest = 1.23 × 102 n m-3, median = 4.48 n m-3). These are perhaps re-suspended particles from the bed load, or stem from shores as diffuse input. This study addresses a gap in research by examining time-resolved microplastic pollution in a major European river. It offers data on microplastic levels in the water column and in suspended particulate matter.