Glacier releases of heavy metals in Kongsfjorden: What are the ecosystem impacts?

Abstract

While climate change is of global concern, its impacts are especially rapid and pronounced in Arctic ecosystems. Arctic glaciers have been particularly impacted, with increasing melt and retreat in conjunction with shifts in riverine freshwater and sediment discharge. Arctic fjords are the ultimate recipients of glacial discharge and a plethora of heavy metals released from glacial environments. However, there is currently very poor understanding of the fate and bioavailability of heavy metals in downstream ecosystems, undergoing rapid change. The METALLICA (MEltwater release of heavy meTALs from gLacIer to ocean in a Changing Arctic) project provides interdisciplinary and integrated understanding of the glacial drivers, transport pathways and impacts of heavy metals on the marine ecosystem of Kongsfjorden, Svalbard, a well-recognized Climate Change Natural Laboratory. The METALLICA project aims to trace heavy metal bioavailability to and cycling in the fjord ecosystem using an end-to-end approach (i.e., from phytoplankton to zooplankton, fish, benthos and seabirds). To do so, an extensive biological sampling program was performed between April and September 2024, including two fjord transects during the spring freshet (June) and peak run-off (July/August) periods. Overall, the METALLICA project aims to deliver ground-breaking mechanistic understanding of the cycling, export and ecosystem impact of heavy metals released from Arctic glaciers to fjords, ultimately developing a novel conceptual framework to support the future prediction and management of toxicity impacts on critical fjord ecosystem goods and services