We conducted a multiple-stressor experiment to evaluate the response of the still poorly studied key Antarctic cryptophyte species Geminigera cryophila (CCMP 2564, isolated from the Southern Ocean and obtained from Matt Johnson's Laboratory of Protistan Ecology at the Woods Hole Oceanography Institute, United States) to warming in combination with ocean acidification and high irradiance. Based on the thermal growth response of G. cryophila, we grew the cryptophyte at suboptimal (2°C) and optimal (4°C) temperatures in combination with two light intensities (medium light: 100 μmol photons/m2/s and high light [HL]: 500 μmol photons/m2/s) under ambient (400 μatm pCO2) and high pCO2 (1000 μatm pCO2) conditions.

In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2022) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2024-01-26.