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Distinct iron cycling in a Southern Ocean eddy


Ellwood, MJ and Strzepek, RF and Strutton, PG and Trull, TW and Fourquez, M and Boyd, PW, Distinct iron cycling in a Southern Ocean eddy, Nature Communications, 11, (1) Article 825. ISSN 2041-1723 (2020) [Refereed Article]


Copyright Statement

The Author(s) 2020. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0)

DOI: doi:10.1038/s41467-020-14464-0


Mesoscale eddies are ubiquitous in the iron-limited Southern Ocean, controlling ocean-atmosphere exchange processes, however their influence on phytoplankton productivity remains unknown. Here we probed the biogeochemical cycling of iron (Fe) in a cold-core eddy. In-eddy surface dissolved Fe (dFe) concentrations and phytoplankton productivity were exceedingly low relative to external waters. In-eddy phytoplankton Fe-to-carbon uptake ratios were elevated 26 fold, indicating upregulated intracellular Fe acquisition resulting in a dFe residence time of ~1 day. Heavy dFe isotope values were measured for in-eddy surface waters highlighting extensive trafficking of dFe by cells. Below the euphotic zone, dFe isotope values were lighter and coincident with peaks in recycled nutrients and cell abundance, indicating enhanced microbially-mediated Fe recycling. Our measurements show that the isolated nature of Southern Ocean eddies can produce distinctly different Fe biogeochemistry compared to surrounding waters with cells upregulating iron uptake and using recycling processes to sustain themselves.

Item Details

Item Type:Refereed Article
Keywords:iron, Southern Ocean, biogeochemistry, eddy
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Biological oceanography
Objective Division:Environmental Policy, Climate Change and Natural Hazards
Objective Group:Mitigation of climate change
Objective Field:Climate change mitigation strategies
UTAS Author:Strzepek, RF (Dr Robert Strzepek)
UTAS Author:Strutton, PG (Professor Peter Strutton)
UTAS Author:Fourquez, M (Dr Marion Fourquez)
UTAS Author:Boyd, PW (Professor Philip Boyd)
ID Code:137719
Year Published:2020
Web of Science® Times Cited:8
Deposited By:Oceans and Cryosphere
Deposited On:2020-02-28
Last Modified:2020-12-07
Downloads:4 View Download Statistics

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