Publication Date:
2024-05-27
Description:
The present study investigates the combined effect of phosphorous limitation, elevated partial pressure of CO2 (pCO2) and temperature on a calcifying strain of Emiliania huxleyi (PML B92/11) by means of a fully controlled continuous culture facility. Two levels of phosphorous limitation were consecutively applied by renewal of culture media (N:P = 26) at dilution rates (D) of 0.3 d- and 0.1 d-1. CO2 and temperature conditions were 300, 550 and 900 µatm pCO2 at 14 °C and 900 µatm pCO2 at 18 °C. In general, the steady state cell density and particulate organic carbon (POC) production increased with pCO2, yielding significantly higher concentrations in cultures grown at 900 µatm pCO2 compared to 300 and 550 µatm pCO2. At 900 µatm pCO2, elevation of temperature as expected for a greenhouse ocean, further increased cell densities and POC concentrations. In contrast to POC concentration, C-quotas (pmol C cell-1) were similar at D = 0.3 d-1 in all cultures. At D = 0.1 d-1, a reduction of C-quotas by up to 15% was observed in the 900 µatm pCO2 at 18 °C culture. As a result of growth rate reduction, POC:PON:POP ratios deviated strongly from the Redfield ratio, primarily due to an increase in POC. Ratios of particulate inorganic and organic carbon (PIC:POC) ranged from 0.14 to 0.18 at D = 0.3 d-1, and from 0.11 to 0.17 at D = 0.1 d-1, with variations primarily induced by the changes in POC. At D = 0.1 d-1, cell volume was reduced by up to 22% in cultures grown at 900 µatm pCO2. Our results indicate that changes in pCO2, temperature and phosphorus supply affect cell density, POC concentration and size of E. huxleyi (PML B92/11) to varying degrees, and will likely impact bloom development as well as biogeochemical cycling in a greenhouse ocean.
Keywords:
Alkalinity, total; Aragonite saturation state; Bicarbonate ion; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria (〈20 L); Calcite saturation state; Calculated, see reference(s); Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, organic, particulate; Carbon, organic, particulate, production per cell; Carbon, organic, particulate/Nitrogen, organic, particulate ratio; Carbon, organic, particulate/Phosphorus, organic, particulate ratio; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Chromista; Colorimetry; Element analyser CNS, EURO EA; Emiliania huxleyi; EPOCA; EUR-OCEANS; European network of excellence for Ocean Ecosystems Analysis; European Project on Ocean Acidification; Experimental treatment; Experiment day; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Haptophyta; Infrared gas analyzer (LI-COR LI-6252); Laboratory experiment; Laboratory strains; Light:Dark cycle; Macro-nutrients; Measured; Nitrate; Nitrogen, inorganic, dissolved; Nitrogen, organic; Nitrogen, organic, particulate/Phosphorus, organic, particulate ratio; Not applicable; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Particulate organic carbon, per cell; Particulate organic carbon production; Particulate organic nitrogen per cell; Particulate organic nitrogen production; Particulate organic phosphorus per cell; Particulate organic phosphorus production; Pelagos; pH; Phosphate; Phosphorus, inorganic; Phosphorus, organic, particulate; Phosphorus, organic, particulate, production per cell; Phytoplankton; Primary production/Photosynthesis; Production of particulate organic nitrogen; Radiation, photosynthetically active; Revelle factor; Salinity; Salinometer - Tropic Marin Sea Salt, Dr. Biener GmbH, Germany; Sample ID; Single species; Spectrophotometry; Temperature; Temperature, water; WTW 340i pH-analyzer and WTW SenTix 81-electrode
Type:
Dataset
Format:
text/tab-separated-values, 1068 data points
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