Publication Date:
2024-03-15
Description:
The invasion of anthropogenic carbon dioxide into the surface ocean is altering seawater carbonate speciation, a process commonly called ocean acidification. The high latitude waters of the Southern Ocean are one of the primary and most severely affected regions. Coccolithophores are an important phytoplankton group, responsible for the majority of pelagic calcium carbonate production in the world's oceans, with a distribution that ranges from tropical to polar waters. Emiliania huxleyi is numerically the most abundant coccolithophore species and appears in several different ecotypes. We tested the effects of ocean acidification on 3 carefully selected E. huxleyi ecotypes isolated from the Southern Ocean. Their responses were measured in terms of growth, photosynthesis, calcification, cellular geometry, and stoichiometry. The 3 ecotypes exhibited differing sensitivities in regards to seawater carbonate chemistry when cultured at the same temperature (14°C) and continuous light (110 µmol photons/m2/s). Under future ocean acidification scenarios, particulate inorganic to organic carbon ratios (PIC:POC) decreased by 38-44, 47-51 and 71-98% in morphotype A 'over-calcified' (A o/c), A and B/C, respectively. All ecotypes reduced their rate of calcification, but the cold-water adapted ecotype (morphotype B/C) was by far the most sensitive, and almost ceased calcification at partial pressure of carbon dioxide ( pCO2) levels above 1000 µatm. We recommend that future surveys for E. huxleyi cells in the Southern Ocean should include the capability of recognising 'naked cells' by molecular and microscopic tools. The distinct differences in the physiological responses of these 3 dominant Southern Ocean coccolithophore ecotypes are likely to have consequences for future coccolithophore community structures and thereby the Southern Ocean carbon cycle.
Keywords:
Alkalinity, total; Alkalinity, total, standard deviation; Aragonite saturation state; Bicarbonate ion; Bicarbonate ion, standard deviation; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria (〈20 L); Calcification/Dissolution; Calcite saturation state; Calcite saturation state, standard deviation; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbon, inorganic, particulate, per cell; Carbon, organic, particulate, per cell; Carbon, organic, particulate/Nitrogen, organic, particulate ratio; Carbon, organic, particulate/Nitrogen, organic, particulate ratio, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard deviation; Cell, diameter; Cell, diameter, standard deviation; Cell biovolume; Cell biovolume, standard deviation; Chromista; Coccoliths, diameter; Coccoliths, diameter, standard deviation; Coccoliths, volume; Coccoliths, volume, standard deviation; Emiliania huxleyi; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Growth rate; Growth rate, standard deviation; Haptophyta; Laboratory experiment; Laboratory strains; Not applicable; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Particulate inorganic carbon, production, standard deviation; Particulate inorganic carbon/particulate organic carbon ratio; Particulate inorganic carbon/particulate organic carbon ratio, standard deviation; Particulate inorganic carbon per cell, standard deviation; Particulate inorganic carbon production per cell; Particulate organic carbon, production, standard deviation; Particulate organic carbon content per cell, standard deviation; Particulate organic carbon production per cell; Particulate organic nitrogen per cell; Particulate organic nitrogen per cell, standard deviation; Particulate organic nitrogen production, standard deviation; Pelagos; pH; pH, standard deviation; Phytoplankton; Potentiometric titration; Primary production/Photosynthesis; Production of particulate organic nitrogen; Registration number of species; Salinity; Single species; Species; Strain; Temperature, water; Type; Uniform resource locator/link to reference
Type:
Dataset
Format:
text/tab-separated-values, 2082 data points
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