Molecules to marinescapes: the characterization of microbial life in the Arctic Ocean

Abstract

Microbes are the base of all marine food webs and comprise >90% of all living biomass in the world’s oceans. Microbial life and functioning in high-latitude seas is characterized by the predominance of unknown species that encode uncharacterized genes, replenish nutrients, and modulate ecosystem health by interfacing with disease processes. This research elucidates eukaryotic microbial diversity and functionality in Arctic and sub-Arctic marine environments by describing the culturable and genetic diversity of eukaryotic microbes and the life histories of marine fungi belonging to the Chytridiomycota. This work includes the description of two new mesomycetozoean species, the assembled and annotated genome of Sphaeroforma sirkka, the first description of a cryptic carbon cycle (the mycoloop) mediated by fungi from any marine environment, and the description of large-scale eukaryotic microbial diversity patterns driven by temperature and latitude in the eastern Bering Sea. These results help establish a valuable baseline of microbial diversity in high latitude seas.