Seawater carbonate chemistry and photosynthesis and dark respiration of Thalassiosira weissflogii (diatom), supplement to: Li, Futian; Fan, Jiale; Hu, Lili; Beardall, John; Xu, Juntian (2019): Physiological and biochemical responses of Thalassiosira weissflogii (diatom) to seawater acidification and alkalization. ICES Journal of Marine Science

• Main Authors: Li, Futian, Fan, Jiale, Hu, Lili, Beardall, John, Xu, Juntian
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2019
• Subjects: Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria <20 L; Chromista; Growth/Morphology; Laboratory experiment; Laboratory strains; Not applicable; Pelagos; Phytoplankton; Primary production/Photosynthesis; Respiration; Single species; Thalassiosira weissflogii; Type; Species; Registration number of species; Uniform resource locator/link to reference; Treatment; Replicate; Growth rate; Chlorophyll a per cell; Biogenic silica, per cell; Change; Net oxygen evolution, per cell; Respiration rate, oxygen, dark per cell; Cell biovolume; Surface area; Cell surface area/cell volume ratio; Biogenic silica per surface area; Temperature, water; Salinity; pH; Alkalinity, total; Carbon, inorganic, dissolved; Bicarbonate ion; Carbon dioxide; Carbonate system computation flag; Fugacity of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide water at sea surface temperature wet air; Carbonate ion; Aragonite saturation state; Calcite saturation state; Calculated using seacarb after Nisumaa et al. 2010; Ocean Acidification International Coordination Centre OA-ICC; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.907928; https://doi.pangaea.de/10.1594/PANGAEA.907928

Increasing atmospheric pCO2 leads to seawater acidification, which has attracted considerable attention due to its potential impact on the marine biological carbon pump and function of marine ecosystems. Alternatively, phytoplankton cells living in coastal waters might experience increased pH/decreased pCO2 (seawater alkalization) caused by metabolic activities of other photoautotrophs, or after microalgal blooms. Here we grew Thalassiosira weissflogii (diatom) at seven pCO2 levels, including habitat-related lowered levels (25, 50, 100, and 200 µatm) as well as present-day (400 µatm) and elevated (800 and 1600 µatm) levels. Effects of seawater acidification and alkalization on growth, photosynthesis, dark respiration, cell geometry, and biogenic silica content of T. weissflogii were investigated. Elevated pCO2 and associated seawater acidification had no detectable effects. However, the lowered pCO2 levels (25-100 µatm), which might be experienced by coastal diatoms in post-bloom scenarios, significantly limited growth and photosynthesis of this species. In addition, seawater alkalization resulted in more silicified cells with higher dark respiration rates. Thus, a negative correlation of biogenic silica content and growth rate was evident over the pCO2 range tested here. Taken together, seawater alkalization, rather than acidification, could have stronger effects on the ballasting efficiency and carbon export of T. weissflogii. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2019) 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). The date of carbonate chemistry calculation by seacarb is 2019-10-24.