Microbial eukaryotes in an arctic marine ecosystem: who are they, where are they and how do they interact with their environment?

Arctic ecosystems are changing, and the urgency to understand the biodiversity and functional links of todays? ecosystems is apparent. The freshening of the Arctic Ocean has already led to a shift in the microbial communities, potentially altering the who le arctic food web from microbes to whales. Marine microbes represent a plethora of divergent evolutionary lineages from all three domains of life (Archaea, Bacteria and Eukaryota). Although their diversity in various marine habitats has been investigated throughout the last decade using molecular tools (metagenomics), their function and importance in the marine ecosystem is to a large degree unknown. The aim of this project is to identify the key species, investigate their seasonality and biogeography, a nd determine the environmental parameters that govern their existence in different systems (e.g. fjords, open water, sea ice) with special emphasis on polar night ecology.