Skip to main content
Research project

Supply of iron from shelf sediments to the ocean

Project overview

Iron is essential to all life forms in the ocean and can limit primary production when at very low concentrations. Of the sources of iron to the ocean, ocean shelf sediments have been suggested to represent the largest. However, we have very limited understanding of exactly how this iron may be released from sediments, how it can be transported into the ocean interior and what processes can impact the flux of this essential element.

In goal of this project was to quantify fluxes of iron from northwest European shelf seas into the adjacent North Atlantic Ocean. We utilised trace metal clean sampling techniques, with associated physical diffusion and advection measurements, to determine the supply of dissolved, colloidal and particulate forms of iron from sediments and their subsequent fate in shelf sea waters and during export to the North Atlantic Ocean. We used iron isotopes, physical-chemical iron species characterisation and geochemical tracers to quantify the iron supply, attenuation and export processes. This was the first study to follow the “iron footprint” from the sediment to the open ocean in such a comprehensive manner.

This project was conducted in collaboration with the University of Plymouth, the University of Edinburgh and CEFAS.


Lead researcher

Professor Rachael James

Professor of Geochemistry

Research interests

  • Enhanced rock weathering and other techniques for removing carbon dioxide from the atmosphere
  • Novel isotopic signatures of biogeochemical cycling, including iron, chromium, lithium and magnesium, and the response of biogeochemcal cycles to global environmental change

Connect with Rachael

Research outputs

Kechen Zhu,
Antony J. Birchill,
Angela Milne,
Simon Ussher,
Matthew P. Humphreys,
Nealy Carr,
Claire Mahaffey,
Maeve C. Lohan,
Eric P. Achterberg,
& Martha Gledhill
, 2021 , Marine Chemistry , 237
Type: article
Katrin Schmidt,
Antony Birchill,
Maeve Lohan,
Angela Milne,
Silvia Pardo,
Timothy Smyth,
Glen Tarran,
Claire E. Widdicombe,
E. Malcolm S. Woodward,
& S. Ussher
, 2020 , Global Change Biology , 26 (10) , 5574--5587
Type: article
Paul J. Worsfold,
Eric P. Achterberg,
Antony J. Birchill,
Robert Clough,
Ivo Leito,
Angela Milne,
& Simon J. Ussher
, 2019 , Frontiers in Marine Science , 5
Type: article
A.J. Birchill,
N.T. Hartner,
K. Kunde,
B. Siemering,
C. Daniels,
D. González-Santana,
A. Milne,
S.J. Ussher,
P.J. Worsfold,
K. Leopold,
S.C. Painter,
, 2019 , Scientific Reports , 9 (1) , 1--12
Type: article
D. Rusiecka,
M. Gledhill,
A. Milne,
E. P. Achterberg,
A. L. Annett,
S. Atkinson,
A. Birchill,
J. Karstensen,
C. Mariez,
R. Middag,
J. M. Rolison,
T. Tanhua,
S. Ussher,
& D. Connelly
, 2018 , Geophysical Research Letters , 45 (6) , 2734--2743
Type: article
Back to top