Samples were collected at eight locations along Langseth Ridge, Arctic Ocean using a CTD and Multicorer (MUC). Water samples were extracted using the PowerWater® DNA Isolation Kit (Qiagen, Germany) and the MUC samples were extracted using the MoBio FastDNA™ Spin kit (MP Biomedicals, USA). Thereafter, DNA was subjected to Illumina Miseq library preparation and paired-end tag sequencing (2 x 300 bp), in triplicate, at the Centrum für Biotechnologie (CeBiTec University of Bielefeld, Bielefeld, Germany). We used multiple primers to target different regions of the 16S rRNA gene.