This dataset contains dissolved iron concentrations (Fe(II) + Fe(III), µmol/l) acquired between July 2011 and March 2012 (n=1780) using the CHEMINI Fe, a CHEmical MINIaturized analyser (samples taken every 12 hours, without in situ calibration using a 25 µmol/l iron standard, Vuillemin et al., 2009). The sample inlet was positioned on the mussel bed at the base of the Tour Eiffel edifice of the Lucky Strike hydrothermal vent (1695 depth).