In this study, we provided an overview of macro- and mesoplastic concentrations, categories, ages, and origin over several years in the water column of the river Waal, in the Netherlands. The most dominant macro- and mesoplastic categories were ‘Miscellaneous plastic waste’, including “Plastic film 2.5 - 50 cm (soft)” and “Plastic film 0 - 2.5 cm (soft)” as main 29 categories. Macro- and mesoplastic categories were found to show limited variability during several years of monitoring. The mean macroplastic concentration (± SD) ranged between 2.2 × 10-3 30 ± 0.001 and 7.4 × 10-3 ± 0.003 particles.m-3 31 for October 2020 and November 2018, respectively. The origin of the plastics (e.g., countries) also showed little variability during monitoring. The consistency of several characteristics of the collected plastic suggests that the same sources were responsible for the macro- and mesoplastic input into the river Waal during low discharges and over multiple years. We present the first temporal assessment of macro- and mesoplastic concentrations and composition in the water column of the river Waal.

Date Submitted: 2023-03-18

Issued: 2021-04-30