Seawater carbonate chemistry and its effects on properties and sinking velocity of aggregates of the coccolithophore Emiliania huxleyi, 2010, supplement to: Biermann, Antje; Engel, Anja (2010): Effect of CO2 on the properties and sinking velocity of aggregates of the coccolithophore Emiliania huxleyi. Biogeosciences, 7(3), 1017-1029

• Main Authors: Biermann, Antje, Engel, Anja
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2010
• Subjects: Biomass/Abundance/Elemental composition; Chromista; Containers and aquaria 20-1000 L or < 1 m**2; Emiliania huxleyi; Growth/Morphology; Haptophyta; Laboratory experiment; Laboratory strains; Not applicable; Other studied parameter or process; Pelagos; Phytoplankton; Single species; Experimental treatment; DATE/TIME; Experiment day; Salinity; Temperature, water; LightDark cycle; Radiation, photosynthetically active; pH; pH, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; Partial pressure of carbon dioxide water at sea surface temperature wet air; Carbon dioxide, partial pressure, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Particle volume concentration; Particle volume concentration, standard deviation; Carbon, total, particulate; Carbon, total, particulate, standard deviation; Carbon, organic, particulate; Carbon, organic, particulate, standard deviation; Carbon, inorganic, particulate; Carbon, inorganic, particulate, per volume, standard deviation; Nitrogen, total, particulate; Nitrogen, total, standard deviation; Bacteria, dry mass; Bacteria, dry mass, standard deviation; Bacteria; Bacteria, abundance, standard deviation; Sinking velocity; Sinking velocity, standard deviation; Cells equivalent spherical diameter; Cells equivalent spherical diameter, standard deviation; Density; Density, standard deviation; Porosity; Porosity, standard deviation; Particulate inorganic carbon/particulate organic carbon ratio; Particulate inorganic carbon/particulate organic carbon ratio, standard deviation; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Carbon, inorganic, dissolved; Aragonite saturation state; Conductivity meter WTW, Weilheim, Gemany; Conductivity and pH meter, pH/Cond 340i WTW, Weilheim; Alkalinity, Gran titration Gran, 1950; Calculated using CO2SYS; Element analyser CNS, EURO EA; Calculated; FACSCalibur flow-cytometer Becton Dicinson; see references; Calculated using seacarb after Nisumaa et al. 2010; European network of excellence for Ocean Ecosystems Analysis EUR-OCEANS; European Project on Ocean Acidification EPOCA; Ocean Acidification International Coordination Centre OA-ICC; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.778432; https://doi.pangaea.de/10.1594/PANGAEA.778432

Coccolithophores play an important role in organic matter export due to their production of the mineral calcite that can act as ballast. Recent studies indicated that calcification in coccolithophores may be affected by changes in seawater carbonate chemistry. We investigated the influence of CO2 on the aggregation and sinking behaviour of the coccolithophore Emiliania huxleyi (PML B92/11) during a laboratory experiment. The coccolithophores were grown under low (~180 µatm), medium (~380 µatm), and high (~750 µatm) CO2 conditions. Aggregation of the cells was promoted using roller tables. Size and settling velocity of aggregates were determined during the incubation using video image analysis. Our results indicate that aggregate properties are sensitive to changes in the degree of ballasting, as evoked by ocean acidification. Average sinking velocity was highest for low CO2 aggregates (~1292 m d-1) that also had the highest particulate inorganic to particulate organic carbon (PIC/POC) ratio. Lowest PIC/POC ratios and lowest sinking velocity (~366 m d-1) at comparable sizes were observed for aggregates of the high CO2 treatment. Aggregates of the high CO2 treatment showed a 4-fold lower excess density (~4.2*10**-4 g cm**-3) when compared to aggregates from the medium and low CO2 treatments (~1.7 g*10**-3 cm**-3). We also observed that more aggregates formed in the high CO2 treatment, and that those aggregates contained more bacteria than aggregates in the medium and low CO2 treatment. If applicable to the future ocean, our findings suggest that a CO2 induced reduction of the calcite content of aggregates could weaken the deep export of organic matter in the ocean, particularly in areas dominated by coccolithophores. : 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).