“…Although local sources and pathways, e.g., rivers [177,57,197], wastewater effluents [132,64,186,79], garbage dumping sites [65], and industries [68,128] may contribute significantly to marine plastic pollution in the Arctic we have little knowledge about the quantity and quality of plastic pollution originating from them. One approach to distinguishing different sources can be to measure typical signatures of MPs in a given water mass [127,135]. MP compositions have been observed to differ between water masses, sediment types and environmental matrices where, e.g., sea ice contains more fragments [150,102,186] than seawater, which is often dominated by fibres [127,186,120,159].…”