This case study of Kongsfjorden, western coastal Svalbard, provides insights on how freshwater runoff from marine- and land-terminating glaciers influences the biogeochemical cycles and distribution patterns of carbon, nutrients, and trace elements in an Arctic fjord system. We collected samples from the water column at stations along the fjord axis and proglacial river catchments, and analyzed concentrations of dissolved trace elements, together with dissolved nutrients, as well as alkalinity and dissolved inorganic carbon. Statistical tools were applied to identify and quantify biogeochemical processes within the fjord that govern the constituent distributions. Our results suggest that the glacier type affects nutrient availability and, therefore, primary production. Glacial discharge from both marine-terminating glaciers and riverine discharge from land-terminating glaciers are important sources of dissolved trace elements (dAl, dMn, dCo, dNi, dCu, and dPb) that are involved in biological and scavenging processes within marine systems. We identified benthic fluxes across the sediment-water interface to supply fjord waters with silicate, dFe, dCu, and dZn. Our data show that intensive carbonate weathering in proglacial catchments supplies fjord waters with additional dissolved carbonates and, therefore, attenuates reduced buffering capacities caused by glacial runoff. Our study provides valuable insight into biogeochemical processes and carbon cycling within a climate-sensitive, high-latitude fjord region, which may help predict Arctic ecosystem changes in the future.
Key Points
- Nutrient, trace element, and carbon species distributions are influenced by glacial discharge of land- and marine-terminating glaciers
- Discharge of marine- and land-terminating glaciers is an important source of bio-essential trace elements
- Progressive glacier retreat will likely impact biotic and abiotic carbon uptake in the future
Plain Language Summary
Arctic regions are particularly vulnerable to climate change and are considerably influenced by anthropogenic impacts. However, the scientific community currently lacks sufficient information on the mechanisms and drivers of these environmental changes, and the consequences that may arise for Arctic ecosystems. Our study provides insights into the distribution patterns of carbon, nutrients, and trace elements in fjord systems influenced by freshwater supply from melting glaciers. We collected water samples from the water column of Kongsfjorden (Svalbard, Norway) and from glacier-fed rivers draining into the fjord. Our results show that freshwater from glaciers is an important source of nutrients, and trace elements that are involved in biological processes within coastal areas. In the future, we predict Arctic fjords will become less productive ecosystems, as a result of the progressive melting and glacier retreat. Ultimately, this has the potential to alter the circulation of water masses and consequently change the redistribution of nutrients and essential trace elements in the water column.
Schmidt C. E., Pröfrock D., Steinhoefel G., Stichel T., Mears C., Wehrmann L. M. & Thomas H., 2025. The contrasting role of marine‐and land‐terminating glaciers on biogeochemical cycles in Kongsfjorden, Svalbard. Global Biogeochemical Cycles 39(1): e2023GB008087. doi: 10.1029/2023GB008087. Article.
