Abstract
The Greenland Ice Sheet is melting at an unprecedented rate, and as a result, the fjords and continental shelves around Greenland are exposed to an increasing freshwater runoff. These coastal ecosystems sustain a high marine productivity and harbour economically important fisheries. Yet, a detailed understanding of how the melting of the Greenland Ice Sheet impacts the coastal ecology and biogeochemistry is currently lacking. Better insights are urgently needed to predict how the natural marine ecosystem functioning will respond and how fisheries will be affected by ongoing climate change. Here, we hypothesize that large marine-terminating glaciers are crucial to sustain the high productivity in Greenland fjords. Upwelling induced by subglacial freshwater discharge and mixing by icebergs play an important role in the supply of nutrients to the surface waters, thus substantially stimulating biological production. These upwelling mechanisms are lacking in fjords with land-terminating glaciers, which hence show a lower productivity. To investigate this hypothesis, we will conduct hydrographic surveys and install state-of-the-art autonomous moorings in multiple Greenlandic fjords. Novel data analysis methods and comparison of observational data with numerical modelling will allow to quantify the impact of melting glaciers on the various factors (vertical mixing, light and nutrients) that govern primary production. This way, this project will increase our fundamental understanding of how glaciers influence marine productivity and how high-latitude marine ecosystems will be affected by climate change.
Netherlands