Small Arctic rivers transport legacy contaminants from thawing catchments to coastal areas in Kongsfjorden, Svalbard

Decades of atmospheric and oceanic long-range transport from lower latitudes have resulted in deposition and storage of persistent organic pollutants (POPs) in Arctic regions. With increased temperatures, melting glaciers and thawing permafrost may serve as a secondary source of these stored POPs to freshwater and marine eco-systems. Here, we present concentrations and composition of legacy POPs in glacier-and permafrost-influenced rivers and coastal waters in the high Arctic Svalbard fjord Kongsfjorden. Targeted contaminants include poly-chlorinated biphenyls (PCBs), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), hexa-chlorocyclohexanes (HCHs) and chlordane pesticides. Dissolved (defined as fraction filtered through 0.7 mu m GF/ F filter) and particulate samples were collected from rivers and near-shore fjord stations along a gradient from the heavily glaciated inner fjord to the tundra-dominated catchments at the outer fjord. There were no differ-ences in contaminant concentration or pattern between glacier and tundra-dominated catchments, and the general contaminant pattern reflected snow melt with some evidence of pesticides released with glacial melt-water. Rivers were a small source of chlordane pesticides, DDTs and particulate HCB to the marine system and the particle-rich glacial meltwater contained higher concentrations of particle associated contaminants compared to the fjord. This study provides rare insight into the role of small Arctic rivers as in transporting legacy con-taminants from thawing catchments to coastal areas. Results indicate that the spring thaw is a source of con-taminants to Kongsfjorden, and that expected increases in runoff on Svalbard and elsewhere in the Arctic could have implications for the contamination of Arctic coastal food-webs.

Automated summary

Decades of long-range transport from lower latitudes have led to the deposition and storage of persistent organic pollutants in Arctic regions. This study focuses on the concentrations and composition of legacy pollutants in rivers and coastal waters influenced by glaciers and permafrost. Results show that these small Arctic rivers play an important role in transporting contaminants to coastal areas, and the spring thaw is a significant source of pollution in Kongsfjorden.