In:
Biogeosciences, Copernicus GmbH, Vol. 19, No. 8 ( 2022-04-20), p. 2101-2120
Abstract:
Abstract. Hydrothermal vents modify and displace subsurface
dissolved organic matter (DOM) into the ocean. Once in the ocean, this DOM
is transported together with elements, particles, dissolved gases and
biomass along with the neutrally buoyant plume layer. Considering the number
and extent of actively venting hydrothermal sites in the oceans, their
contribution to the oceanic DOM pool may be substantial. Here, we investigate
the dynamics of DOM in relation to hydrothermal venting and related
processes at the as yet unexplored Aurora hydrothermal vent field within the
ultraslow-spreading Gakkel Ridge in the Arctic Ocean at 82.9∘ N.
We examined the vertical distribution of DOM composition from sea ice to
deep waters at six hydrocast stations distal to the active vent and its
neutrally buoyant plume layer. In comparison to background seawater, we
found that the DOM in waters directly affected by the hydrothermal plume was
molecularly less diverse and 5 %–10 % lower in number of molecular formulas
associated with the molecular categories related to lipid and protein-like
compounds. On the other hand, samples that were not directly affected by the
plume were chemically more diverse and had a higher percentage of chemical
formulas associated with the carbohydrate-like category. Our results suggest
that hydrothermal processes at Aurora may influence the DOM distribution in
the bathypelagic ocean by spreading more thermally and/or chemically induced
compositions, while DOM compositions in epipelagic and mesopelagic layers
are mainly governed by the microbial carbon pump dynamics and surface-ocean–sea-ice interactions.
Type of Medium:
Online Resource
ISSN:
1726-4189
DOI:
10.5194/bg-19-2101-2022
DOI:
10.5194/bg-19-2101-2022-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2022
detail.hit.zdb_id:
2158181-2
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