Seawater carbonate chemistry and processes during experiments with Emiliania huxleyi (PML B93/11A), supplement to: Riebesell, Ulf; Zondervan, Ingrid; Rost, Bjoern; Tortell, Philippe Daniel; Zeebe, Richard E; Morel, Francois M M (2000): Reduced calcification of marine plankton in response to increased atmospheric CO2. Nature, 407, 364-367

• Main Authors: Riebesell, Ulf, Zondervan, Ingrid, Rost, Bjoern, Tortell, Philippe Daniel, Zeebe, Richard E, Morel, Francois M M
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2000
• Subjects: Bottles or small containers/Aquaria <20 L; Calcification/Dissolution; Chromista; Entire community; Growth/Morphology; Haptophyta; Laboratory experiment; Laboratory strains; Light; Not applicable; Open ocean; Other studied parameter or process; Pelagos; Phytoplankton; Primary production/Photosynthesis; Single species; Temperate; Identification; LightDark cycle; Radiation, photosynthetically active; Salinity; Temperature, water; Carbonate system computation flag; pH; Carbon dioxide, total; Carbon dioxide; Partial pressure of carbon dioxide water at sea surface temperature wet air; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Carbon, inorganic, dissolved; Alkalinity, total; Aragonite saturation state; Calcite saturation state; Carbon, organic, particulate, per cell; Production of particulate organic carbon per cell; Carbon, inorganic, particulate, per cell; Particulate inorganic carbon production per cell; Carbon organic/inorganic ratio; Growth rate; Growth rate, carbon-specific, per cell; δ13C, dissolved inorganic carbon; δ13C, carbon dioxide, atmospheric; δ13C, particulate organic carbon; δ13C, particulate inorganic carbon; Isotopic fractionation, during photosynthis; Experiment; Calculated using seacarb after Nisumaa et al. 2010; pH meter, WTW, pH 3000; UIC 5012 coulometer; Calculated; Colorimetry; Alkalinity, Gran titration Gran, 1950; Mass spectrometer ANCA-SL 20-20 Europa Scientific; Mass spectrometer Finnigan MAT 252; Calculated, see references; Calculated after Freeman & Hayes 1992; European network of excellence for Ocean Ecosystems Analysis EUR-OCEANS; European Project on Ocean Acidification EPOCA; Ocean Acidification International Coordination Centre OA-ICC; Hayes; Pacific; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.726883; https://doi.pangaea.de/10.1594/PANGAEA.726883

The formation of calcareous skeletons by marine planktonic organisms and their subsequent sinking to depth generates a continuous rain of calcium carbonate to the deep ocean and underlying sediments. This is important in regulating marine carbon cycling and ocean-atmosphere CO2 exchange. The present rise in atmospheric CO2 levels causes significant changes in surface ocean pH and carbonate chemistry. Such changes have been shown to slow down calcification in corals and coralline macroalgae, but the majority of marine calcification occurs in planktonic organisms. Here we report reduced calcite production at increased CO2 concentrations in monospecific cultures of two dominant marine calcifying phytoplankton species, the coccolithophorids Emiliania huxleyi and Gephyrocapsa oceanica . This was accompanied by an increased proportion of malformed coccoliths and incomplete coccospheres. Diminished calcification led to a reduction in the ratio of calcite precipitation to organic matter production. Similar results were obtained in incubations of natural plankton assemblages from the north Pacific ocean when exposed to experimentally elevated CO2 levels. We suggest that the progressive increase in atmospheric CO2 concentrations may therefore slow down the production of calcium carbonate in the surface ocean. As the process of calcification releases CO2 to the atmosphere, the response observed here could potentially act as a negative feedback on atmospheric CO2 levels. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Lavigne and Gattuso, 2011) 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).