Seawater carbonate chemistry and photosynthesis and calcification of the coccolithophore Emiliania huxleyi

• Main Authors: Zhang, Yong, Gao, Kunshan
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2021
• Subjects: Bottles or small containers/Aquaria <20 L; Calcification/Dissolution; Chromista; Emiliania huxleyi; Haptophyta; Laboratory experiment; Laboratory strains; Light; Macro-nutrients; Not applicable; Pelagos; Phytoplankton; Primary production/Photosynthesis; Single species; Type; Species; Registration number of species; Uniform resource locator/link to reference; Treatment; Irradiance; Chlorophyll a per cell; Chlorophyll a, standard deviation; Carotenoids per cell; Carotenoids; Carotenoids/Chlorophyll a ratio; Carotenoids/Chlorophyll a ratio, standard deviation; Maximal electron transport rate, relative; Maximal electron transport rate, relative, standard deviation; Light use efficiency; Light use efficiency, standard deviation; Light saturation point; Light saturation point, standard deviation; Effective photochemical quantum yield; Effective photochemical quantum yield, standard deviation; Net photosynthesis rate per cell; Net photosynthesis rate, standard deviation; Calcification rate of carbon per cell; Calcification rate, standard deviation; Calcification rate/Photosynthesis rate, ratio; Calcification rate/Photosynthesis rate, ratio, standard deviation; Ratio; Ratio, standard deviation; Non photochemical quenching; Non photochemical quenching, standard deviation; Experiment duration; Cell density, natural logarithm; Cell density, natural logarithm, standard deviation; Electron transport rate, relative; Electron transport rate, relative, standard deviation; Salinity; Temperature, water; Partial pressure of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide, standard deviation; pH; pH, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Bicarbonate ion; Bicarbonate ion, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Carbon dioxide; Carbon dioxide, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Carbonate system computation flag; Fugacity of carbon dioxide water at sea surface temperature wet air; Aragonite saturation state; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.932293; https://doi.pangaea.de/10.1594/PANGAEA.932293

Photophysiological responses of phytoplankton to changing multiple environmental drivers are essential in understanding and predicting ecological consequences of ocean climate changes. In this study, we investigated the combined effects of two CO2 levels (410 and 925 μatm) and five light intensities (80 to 480 μmol photons/m**2/s) on cellular pigments contents, photosynthesis and calcification of the coccolithophore Emiliania huxleyi grown under nutrient replete and limited conditions, respectively. Our results showed that high light intensity, high CO2 level and nitrate limitation acted synergistically to reduce cellular chlorophyll a and carotenoid contents. Nitrate limitation predominantly enhanced calcification rate; phosphate limitation predominantly reduced photosynthetic carbon fixation rate, with larger extent of the reduction under higher levels of CO2 and light. Reduced availability of both nitrate and phosphate under the elevated CO2 concentration decreased saturating light levels for the cells to achieve the maximal relative electron transport rate (rETRmax). Light-saturating levels for rETRmax were lower than that for photosynthetic and calcification rates under the nutrient limitation. Regardless of the culture conditions, rETR under growth light levels correlated linearly and positively with measured photosynthetic and calcification rates. Our findings imply that E. huxleyi cells acclimated to macro-nutrient limitation and elevated CO2 concentration decreased their light requirement to achieve the maximal electron transport, photosynthetic and calcification rates, indicating a photophysiological strategy to cope with CO2 rise/pH drop in shoaled upper mixing layer above the thermocline where the microalgal cells are exposed to increased levels of light and decreased levels of nutrients. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2021) 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 2021-05-31.