Nitrogen Fixation Potential in Bathypelagic Sediment of the Ice-Covered Arctic Ocean Revealed Through Long-Term Stable Isotope Incubations.

ABSTRACT: Due to climate change, sea ice more commonly retreats over the shelf breaks in the Arctic Ocean, impacting sea ice-pelagic-benthic coupling in the deeper basins. Nitrogen fixation (the reduction of dinitrogen gas to bioavailable ammonia by microorganisms called diazotrophs) is reported from Arctic shelf sediments but is unknown from the Arctic deep sea. We sampled five locations of deep-sea (900-1500 m) surface sediments in the central ice-covered Arctic Ocean to measure potential nitrogen fixation through long-term (> 280 days) stable-isotope (¹⁵N₂) incubations and to study diazotroph community composition through amplicon sequencing of the functional marker gene nifH. We measured low but detectable nitrogen fixation rates at the Lomonosov Ridge (0.6 pmol N g^-1<

SUBMITTER: von Friesen LW 

PROVIDER: S-EPMC12410090 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature