Publication Date:
2024-03-15
Description:
Despite the fact that ocean acidification is considered to be especially pronounced in the Southern Ocean, little is known about CO2-dependent physiological processes and the interactions of Antarctic phytoplankton key species. We therefore studied the effects of CO2 partial pressure (PCO2) (16.2, 39.5, and 101.3 Pa) on growth and photosynthetic carbon acquisition in the bloom-forming species Chaetoceros debilis, Pseudo-nitzschia subcurvata, Fragilariopsis kerguelensis, and Phaeocystis antarctica. Using membrane-inlet mass spectrometry, photosynthetic O2 evolution and inorganic carbon (Ci) fluxes were determined as a function of CO2 concentration. Only the growth of C. debilis was enhanced under high PCO2. Analysis of the carbon concentrating mechanism (CCM) revealed the operation of very efficient CCMs (i.e., high Ci affinities) in all species, but there were species-specific differences in CO2-dependent regulation of individual CCM components (i.e., CO2 and uptake kinetics, carbonic anhydrase activities). Gross CO2 uptake rates appear to increase with the cell surface area to volume ratios. Species competition experiments with C. debilis and P. subcurvata under different PCO2 levels confirmed the CO2-stimulated growth of C. debilis observed in monospecific incubations, also in the presence of P. subcurvata. Independent of PCO2, high initial cell abundances of P. subcurvata led to reduced growth rates of C. debilis. For a better understanding of future changes in phytoplankton communities, CO2-sensitive physiological processes need to be identified, but also species interactions must be taken into account because their interplay determines the success of a species.
Keywords:
Alkalinity, total; Alkalinity, total, standard deviation; Antarctic; Aragonite saturation state; Bicarbonate ion; Bicarbonate ion, reciprocal of photosynthetic affinity value; Bicarbonate ion, reciprocal of photosynthetic affinity value, standard deviation; Bicarbonate uptake/net fixation ratio; Bicarbonate uptake/net fixation ratio, standard deviation; Bicarbonate uptake per chlorophyll a, maximum velocity, standard deviation; Bicarbonate uptake rate, per chlorophyll a, maximum velocity; Bottles or small containers/Aquaria (〈20 L); Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, reciprocal of photosynthetic affinity value; Carbon dioxide, reciprocal of photosynthetic affinity value, standard deviation; Carbon dioxide, standard deviation; Cell surface area/cell volume, standard deviation; Cell surface area/cell volume ratio; Chaetoceros debilis; Chaetoceros debilis/Pseudo-nitzschia subcurvata ratio; Chaetoceros debilis/Pseudo-nitzschia subcurvata ratio, standard deviation; Chromista; Description; Extracellular carbonic anhydrase activity; Extracellular carbonic anhydrase activity, standard deviation; Fragilariopsis kerguelensis; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gross carbon dioxide uptake, half saturation concentration; Gross carbon dioxide uptake, half saturation concentration, standard deviation; Gross carbon dioxide uptake/net fixation ratio; Gross carbon dioxide uptake/net fixation ratio, standard deviation; Gross carbon dioxide uptake per chlorophyll a, maximum velocity, standard deviation; Gross carbon dioxide uptake rate, per chlorophyll a, maximum velocity; Growth/Morphology; Growth rate; Growth rate, standard deviation; Identification; Laboratory experiment; Laboratory strains; Measured by loss of 18O (Silverman, 1982); Net carbon dioxide uptake, half saturation concentration; Net carbon dioxide uptake, half saturation concentration, standard deviation; Net carbon dioxide uptake per chlorophyll a, maximum velocity, standard deviation; Net carbon dioxide uptake rate, per chlorophyll a, maximum velocity; Nitrate; OA-ICC; Ocean Acidification International Coordination Centre; Ochrophyta; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; pH, standard deviation; Phaeocystis antarctica; Phosphate; Photosynthesis carbon dioxide uptake, maximum velocity, standard deviation; Photosynthesis carbon dioxide uptake rate, maximum velocity; Phytoplankton; Potentiometric; Potentiometric titration; Primary production/Photosynthesis; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; Pseudo-nitzschia subcurvata; Salinity; Silicate; Single species; Species; Species interaction; SPP1158; Temperature, water; Treatment
Type:
Dataset
Format:
text/tab-separated-values, 1753 data points
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