Global niche of marine anaerobic metabolisms expanded by particle microenvironments.

Bianchi, Daniele, Weber, Thomas S., Kiko, Rainer and Deutsch, Curtis (2018) Global niche of marine anaerobic metabolisms expanded by particle microenvironments. Nature Geoscience, 11 (4). pp. 263-268. DOI 10.1038/s41561-018-0081-0.

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Abstract

In ocean waters, anaerobic microbial respiration should be confined to the anoxic waters found in coastal regions and tropical oxygen minimum zones, where it is energetically favourable. However, recent molecular and geochemical evidence has pointed to a much broader distribution of denitrifying and sulfate-reducing microbes. Anaerobic metabolisms are thought to thrive in microenvironments that develop inside sinking organic aggregates, but the global distribution and geochemical significance of these microenvironments is poorly understood. Here, we develop a new size-resolved particle model to predict anaerobic respiration from aggregate properties and seawater chemistry. Constrained by observations of the size spectrum of sinking particles, the model predicts that denitrification and sulfate reduction can be sustained throughout vast, hypoxic expanses of the ocean, and could explain the trace metal enrichment observed in particles due to sulfide precipitation. Globally, the expansion of the anaerobic niche due to particle microenvironments doubles the rate of water column denitrification compared with estimates based on anoxic zones alone, and changes the sensitivity of the marine nitrogen cycle to deoxygenation in a warming climate.

Document Type: Article
Research affiliation: OceanRep > SFB 754
OceanRep > GEOMAR > FB3 Marine Ecology > FB3-EOE-B Experimental Ecology - Benthic Ecology
OceanRep > SFB 754 > B8
Refereed: Yes
Open Access Journal?: No
Publisher: Nature Research
Related URLs:
Projects: SFB754
Date Deposited: 16 Apr 2018 10:54
Last Modified: 08 Feb 2021 07:42
URI: https://oceanrep.geomar.de/id/eprint/42758

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