The chemical speciation of iron in the north-east Atlantic Ocean

• Published in: Deep Sea Research Part I: Oceanographic Research Papers
• Main Authors: Boye, Marie, Aldrich, Annette, Berg, Constant M.G. van den, Jong, Jeroen T.M. de, Nirmaier, Hans, Veldhuis, Marcel, Timmermans, Klaas R., Baar, Hein J.W. de
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2006
• Subjects: Atlantic Ocean; Iron speciation; Organic ligands; Iron; North East Atlantic
• Online Access: https://hdl.handle.net/11370/c5b8ecfe-5ca5-4394-90e0-fc148642f28c; https://research.rug.nl/en/publications/c5b8ecfe-5ca5-4394-90e0-fc148642f28c; https://doi.org/10.1016/j.dsr.2005.12.015; https://pure.rug.nl/ws/files/2876907/2006DeepSeaRes1Boye.pdf

The distribution of dissolved iron and its chemical speciation (organic complexation and redox speciation) were studied in the northeastern Atlantic Ocean along 23°W between 37 and 42°N at depths between 0 and 2000 m, and in the upper-water column (upper 200 m) at two stations further east at 45°N10°W and 40°N17°W in the early spring of 1998. The iron speciation data are here combined with phytoplankton data to suggest cyanobacteria as a possible source for the iron binding ligands. The organic Fe-binding ligand concentrations were greater than that of dissolved iron by a factor of 1.5–5, thus maintaining iron in solution at levels well above it solubility. The water column distribution of the organic ligand indicates in-situ production of organic ligands by the plankton (consisting mainly of the cyanobacteria Synechococcus sp.) in the euphotic layer and a remineralisation from sinking biogenic particles in deeper waters. Fe(II) concentrations varied from below the detection limit (