Sediment chemical data, Lake Hazen, Nunavut, Canada, August 4th to 8th, 2016

• Main Authors: Matti Ruuskanen, Graham Colby, Kyra St. Pierre, Vincent St. Louis, Stéphane Aris-Brosou, Alexandre Poulain
• Format: Dataset
• Language: unknown
• Published: Arctic Data Center 2019
• Subjects: high arctic; lakes; sediments; Arctic; Nunavut; Canada; Arctic Lake; Lake Hazen; Snowgoose Bay; glacier*
• Online Access: https://doi.org/10.18739/A2X63B542

This data on porewater chemical concentrations of NH 4 + , NO 2 - /NO 3 - , SO 4 2- , TDP and Cl - , and microprobe data on O 2 , redox potential, and pH in the sediments of Lake Hazen in August 2016 was gathered for a metagenomic study on the structure and functional potential of the sediment microbial community. The title of the study is "High-Arctic lake sediments are enriched in novel Metagenome Assembled Genomes fit for low temperature and oligotrophy". Abstract of the study follows: The Arctic is currently warming at an unprecedented rate, which may affect environmental constraints on the freshwater microbial communities found there. Yet, our knowledge of the community structure and function of High Arctic freshwater microbes remains poor, even though they play key roles in nutrient cycling and other ecosystem services. Here, using high-throughput metagenomic sequencing and genome assembly, we show that sediment microbial communities in the High Arctic’s largest lake by volume, Lake Hazen, are highly diverse and contain novel organisms. These assembled genomes displayed a high prevalence of pathways involved in lipid chemistry, and a low prevalence of nutrient uptake pathways, which might represent adaptations to the specific, extremely oligotrophic conditions in Lake Hazen. A third of the reconstructed genomes were distantly related to known reference genomes, and analysis of marker genes indicated that these novel genomes play key roles in fixing atmospheric nitrogen and assimilating it into organic forms. Furthermore, we observed that the nitrogen and sulfur cycles are catalyzed by a diverse microbial community in these sediments. Increasing nutrient delivery from melting glaciers might lead to disappearance of oligotrophic niches in the sediment and alterations in the microbial community, which might have unforeseen consequences on water quality in northern regions.