Concentrations of total dissolved iron and dissolved manganese measured for the four different mediums used for the experiment without Phaeocystis antarctica cells

Total dissolved Fe (dFe) and Mn (dMn) concentrations were determined in the culture medium (without cells). To this end, 100 mL of seawater were filtered through HCl-cleaned polycarbonate filters (0.2 μm pore size, EMD Millipore, Darmstadt, Germany) using a TMC filtration system and the filtrate collected in a HCl-cleaned polyethylene bottle, which was stored triple bagged at 2 ̊C for analysis. Concentrations of total dFe and dMn were determined on a SeaFast system (Elemental Scientific, Omaha, NE, USA; (Hathorne et al., 2012; Rapp et al., 2017)) coupled to an inductively coupled plasma mass spectrometer (ICP-MS, Element2, Thermo Fisher Scientific, resolution of 2000).