Abstract
The Arctic Ocean is experiencing significant global warming, leading to reduced sea-ice cover, submarine permafrost thawing, and increased river discharge. The East Siberian Sea (ESS) undergoes more significant terrestrial inflow from coastal erosion and river runoff than other Arctic seas. Despite extensive research on environmental changes, microbial communities and their functions in the ESS, which are closely related to environmental conditions, remain largely unexplored. Here, we investigated microbial communities in ESS surface sediments spanning latitudes from 73°N to 77°N using 16S rRNA amplicon sequencing, and reconstructed 211 metagenome-assembled genomes (MAGs) using shotgun metagenome sequencing. Taxonomic analysis identified 209 bacterial MAGs, with the predominant phyla Pseudomonadota (n = 82), Actinobacteriota (n = 38), Desulfobacterota (n = 23), along with 2 archaeal MAGs of Thermoproteota. Notably, 86% of the MAGs (n = 183) could not be classified into known species, indicating the potential presence of novel and unidentified microorganisms in the ESS. This dataset provides invaluable information on the microbial diversity and ecological functions in the rapidly changing ESS.