Seawater, bulk sediment, and sediment fractions from Isfjorden, Svalbard 2021-2023

Sediment and seawater (SW) samples were collected on five sampling campaigns (December 2021, April 2022, June 2022, January 2023, April 2023) in Isfjorden, Svalbard. We fractionated the sediment microbial community into cells in the pore water (PW), cells loosely attached to the grains (LA), and cells firmly attached to the grains (FA). We extracted DNA from the seawater, bulk sediment, and sediment fractions and amplified the V3-V4 region of the 16S rRNA gene using previously described primers (Herlemann et al., 2011). The amplicons were sequenced on a MiSeq (2x300 bp; Illumina Inc., CA, USA) For the January and April 2023 amplicons, additional sequences were obtained via a NextSeq (2x300 bp; Illumina Inc., CA, USA). April 2022 amplicon sequences are available under ENA acession number PRJEB67636.