Please use this identifier to cite or link to this item:
Title: A call for refining the role of humic-like substances in the oceanic iron cycle
Authors: Whitby, Hannah
Planquette, Hélène
Cassar, Nicolas
Bucciarelli, Eva
Osburn, Christopher L.
Janssen, David J.
Cullen, Jay T.
González, Aridane G. 
Völker, Christoph
Sarthou, Géraldine
UNESCO Clasification: 251002 Oceanografía química
Issue Date: 2020
Journal: Scientific Reports 
Abstract: Primary production by phytoplankton represents a major pathway whereby atmospheric CO2 is sequestered in the ocean, but this requires iron, which is in scarce supply. As over 99% of iron is complexed to organic ligands, which increase iron solubility and microbial availability, understanding the processes governing ligand dynamics is of fundamental importance. Ligands within humic-like substances have long been considered important for iron complexation, but their role has never been explained in an oceanographically consistent manner. Here we show iron co-varying with electroactive humic substances at multiple open ocean sites, with the ratio of iron to humics increasing with depth. Our results agree with humic ligands composing a large fraction of the iron-binding ligand pool throughout the water column. We demonstrate how maximum dissolved iron concentrations could be limited by the concentration and binding capacity of humic ligands, and provide a summary of the key processes that could influence these parameters. If this relationship is globally representative, humics could impose a concentration threshold that buffers the deep ocean iron inventory. This study highlights the dearth of humic data, and the immediate need to measure electroactive humics, dissolved iron and iron-binding ligands simultaneously from surface to depth, across different ocean basins.
ISSN: 2045-2322
DOI: 10.1038/s41598-020-62266-7
Source: Scientific Reports [EISSN 2045-2322], v. 10 (1), (Diciembre 2020)
Appears in Collections:Artículos
Adobe PDF (1,91 MB)
Show full item record

Google ScholarTM




Export metadata

Items in accedaCRIS are protected by copyright, with all rights reserved, unless otherwise indicated.