Pelagic and ice-associated microalgae under elevated light and pCO2: Contrasting physiological strategies in two Arctic diatoms

Laboratory experiment on acclimated physiological responses of the Arctic diatoms Thalassiosira hyalina and Melosira arctica towards elevated irradiance (50 vs 300 µmol photons m-2 s-1) and CO2 partial pressures (380 vs. 1000 μatm). Next to growth, elemental composition and biomass production, we assessed detailed photophysiological responses through fluorometry and gas-flux measurements, including respiration and carbon acquisition. Both algal cultures were isolated from the field within 2 years before the experiment, T.hyalina in Kongsjorden, Svalbard, and M.arctica in the Fram Strait close to Svalbard.