Polar and Climate
The polar and high mountains are the planet’s barometers, telling us a great deal about the present and future effects of climate change.
Plastic pollution in the world’s oceans has become of increasing global concern, including in the Arctic Ocean. The primary contributor to this pollution is considered to be land-based sources. While coastal and the marine contributions have been widely studied and quantified, assessments from inland populations through riverine systems have not gained the same attention. Plastic pollution in freshwater systems can be directly linked to human activity, with river-borne plastic closely tied to factors such as population density, urbanisation and industrialisation in catchment areas. Plastic may enter river systems directly through dumping, or enter rivers from the land through natural processes such as wind and rainfall-induced runoff.
The Arctic Ocean constitutes just over 1% of the global ocean volume but receives about 10% of the global river discharge. The majority of rivers flowing into the Arctic Ocean have their headwaters south of the Arctic Circle. The four rivers with the largest yearly runoff to the Arctic Ocean are the Yenisei, Lena, Ob, and Mackenzie rivers, all of which have their headwaters in sub-Arctic regions. Approximately 4 million people live in the Arctic, with the Barents and Russian Arctic region being the most populated. There are at least an additional 50 million people situated within the catchment areas of the rivers flowing into the Arctic.
To address the knowledge gap of Arctic rivers as a source of plastic pollution to the Arctic Ocean, a map was created to provide an overview of rivers connecting population hotspots outside of the Arctic to the Arctic Ocean. River catchments with significant human activity have the potential to act as pathways of plastic pollution into the Arctic Ocean. The highest risk for transport of plastic pollution occurs in summer when river discharge peaks due to snow and ice melt. Currently, our understanding of the transportation and fate of river-borne plastic pollution in the Arctic remains limited. Evidence suggests that only a fraction of land-based plastic pollution reaches the ocean through rivers, and is rather retained in or around waterways. Nevertheless, the Severnaya Dvina river plays a major role in microplastic transport to the White Sea, and reports indicate that Siberia’s Ob, Lena, and Tom (tributary of Ob) rivers contain microplastic. Their river discharge is identified as the second largest source of microplastic, behind Atlantic water input to the Eurasian Basin, one of the two main basins in the Arctic Ocean.
Type: Brochures and Briefs
Author: Eirin Husabø
Year of publication: 2023
Place of publication: GRID-Arendal