Seawater carbonate chemistry and photo-physiological fitness, growth and carbon production of the Antarctic cryptophyte Geminigera cryophila

• Main Authors: Trimborn, Scarlett, Thoms, Silke, Karitter, Pascal, Bischof, Kai
• Format: Dataset
• Language: English
• Published: PANGAEA 2020
• Subjects: Alkalinity; total; Aragonite saturation state; Bicarbonate ion; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria (<20 L); Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; standard deviation; organic; particulate; per cell; production per cell; Carbon/Nitrogen ratio; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Chromista; Connectivity between photosystem II; Cryptophyta; Electron transport rate; absolute; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Functional absorption cross sections of photosystem II reaction centers; Functional photosystem II reaction centers; Antarc*; Antarctic; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.914289; https://doi.org/10.1594/PANGAEA.914289

Ecophysiological studies on Antarctic cryptophytes to assess whether climatic changes such as ocean acidification and enhanced stratification affect their growth in Antarctic coastal waters in the future are lacking so far. This is the first study that investigates the combined effects of the increasing availability of pCO2 (400 and 1000 μatm) and irradiance (20, 200 and 500 μmol photons m-2 s-1) on growth, elemental composition and photo-physiology of the Antarctic cryptophyte Geminigera cryophila. Under ambient pCO2, this species was characterized by a pronounced sensitivity to increasing irradiance with complete growth inhibition at the highest light intensity. Interestingly, when grown under high pCO2 this negative light effect vanished, and it reached the highest rates of growth and particulate organic carbon production at the highest irradiance compared to the other tested experimental conditions. Our results for G. cryophila reveal beneficial effects of ocean acidification in conjunction with enhanced irradiance on growth and photosynthesis. Hence, cryptophytes such as G. cryophila may be potential winners of climate change, potentially thriving better in more stratified and acidic coastal waters and contributing in higher abundance to future phytoplankton assemblages of coastal Antarctic waters.