show Abstracthide AbstractThe Arctic is currently experiencing climate-change related warming, which rapidly affects the environmental constraints on its microbial communities. Yet, our knowledge of the community structure and function of high Arctic freshwater microbes is still lacking, even though they play key roles in nutrient cycling. Here, using high-throughput sequencing, we show that sediment microbial communities in the High Arctic's largest lake by volume, Lake Hazen, are highly diverse and contain novel organisms which genomes we could reconstruct.