Summer sea ice melt and wastewater are important local sources of microlitter to Svalbard waters

[Display omitted] •Arctic sea ice releases sequestered anthropogenic microlitter upon summer melting.•The release coincides with the ice-edge bloom, suggesting high bioavailability.•Microlitter likely originating from a wastewater outlet is detected in a fjord.•Local point- and diffuse sources of microlitter are not negligible in the Arctic.•A multivariate analytical approach is suggested beneficial in microlitter research. Human activities leave traces of marine litter around the globe. The Arctic is, despite its remoteness, emerging as an area of no exception to this environmental issue. Arctic sea ice has previously been found to constitute a temporal sink of microplastics, but the potential release and subsequent fate of microplastics in the marine environment are yet unknown. Furthermore, the relative importance of local sources of microplastics in the Arctic marine environment is under discussion. In this study, the concentration and distribution of anthropogenic microparticles (AMPs,