Soluble and colloidal iron in the oligotrophic North Atlantic and North Pacific

J. Wu, E. Boyle, W. Sunda, L. S. Wen

Research output: Contribution to journalArticle

322 Scopus citations

Abstract

In the oligotrophic North Atlantic and North Pacific, ultrafiltration studies show that concentrations of soluble iron and soluble iron-binding organic ligands are much lower than previously presumed "dissolved" concentrations, which were operationally defined as that passing through a 0.4-micrometer pore filter. Our studies indicate that substantial portions of the previously presumed "dissolved" iron (and probably also iron-binding ligands) are present in colloidal size range. The soluble iron and iron-binding organic ligands are depleted at the surface and enriched at depth, similar to distributions of major nutrients. By contrast, colloidal iron shows a maximum at the surface and a minimum in the upper nutricline. Our results suggest that "dissolved" iron may be less bioavailable to phytoplankton than previously thought and that iron removal through colloid aggregation and settling should be considered in models of the oceanic iron cycle.

Original languageEnglish (US)
Pages (from-to)847-849
Number of pages3
JournalScience
Volume293
Issue number5531
DOIs
StatePublished - Aug 3 2001

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Soluble and colloidal iron in the oligotrophic North Atlantic and North Pacific'. Together they form a unique fingerprint.

  • Cite this