A call for refining the role of humic-like substances in the oceanic iron cycle.

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

SUBMITTER: Whitby H 

PROVIDER: S-EPMC7145848 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature