Seawater carbonate chemistry, stable carbon isotope fractionation and growth rate during experiments with marine phytoplankton community, 1999, supplement to: Burkhardt, Steffen; Riebesell, Ulf; Zondervan, Ingrid (1999): Stable carbon isotope fractionation by marine phytoplankton in response to daylength, growth rate, and CO2 availability. Marine Ecology Progress Series, 194, 31-41

• Main Authors: Burkhardt, Steffen, Riebesell, Ulf, Zondervan, Ingrid
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 1999
• Subjects: Asterionella glacialis; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria <20 L; Chromista; Growth/Morphology; Laboratory experiment; Laboratory strains; Light; Myzozoa; Not applicable; Ochrophyta; Pelagos; Phaedactylum tricornutum; Phytoplankton; Scrippsiella trochoidea; Single species; Skeletonema costatum; Thalassiosira punctigera; Thalassiosira weissflogii; Species; Experimental treatment; Carbonate system computation flag; Salinity; Temperature, water; Radiation, photosynthetically active; LightDark cycle; pH; 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; Silicate; Phosphate; Nitrate; δ13C, carbon dioxide, aquatic; δ13C, particulate organic carbon; Isotopic fractionation, during photosynthis; Growth rate; Experiment; Calculated using seacarb after Nisumaa et al. 2010; Measured; Coulometric titration; Alkalinity, Gran titration Gran, 1950; Calculated; Mass spectrometer Finnigan Delta-S; Mass spectrometer ANCA-SL 20-20 Europa Scientific; 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; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.718103; https://doi.pangaea.de/10.1594/PANGAEA.718103

Stable carbon isotope fractionation (%) of 7 marine phytoplankton species grown in different irradiance cycles was measured under nutrient-replete conditions at a high light intensity in batch cultures. Compared to experiments under continuous light, all species exhibited a significantly higher instantaneous growth rate (pi), defined as the rate of carbon fixation during the photo period, when cultivated at 12:12 h. 16:8 h, or 186 h light:dark (L/D) cycles. Isotopic fractionation by the diatoms Skeletonema costatum, Asterionella glacialis, Thalassiosira punctigera, and Coscinodiscus wailesii (Group I) was 4 to 6% lower in a 16:8 h L/D cycle than under continuous light, which we attribute to differences in pi. In contrast, E, in Phaeodactylum tn'cornutum, Thalassiosira weissflogii, and in the dinoflagellate Scrippsiella trochoidea (Group 11) was largely insensitive to day length-related differences in instantaneous growth rate. Since other studies have reported growth-rate dependent fractionation under N-limited conditions in P. tricornutum, pi-related effects on fractionation apparently depend on the factor controlling growth rate. We suggest that a general relationship between E, and pi/[C02,,,] may not exist. For 1 species of each group we tested the effect of variable CO2 concentration, [COz,,,], on isotopic fractionation. A decrease in [CO2,,,] from ca 26 to 3 pm01 kg-' caused a decrease in E, by less than 3%0 This indicates that variation in h in response to changes in day length has a similar or even greater effect on isotopic fractionation than [COz,,,] m some of the species tested. In both groups E, tended to be higher in smaller species at comparable growth rates. In 24 and 48 h time series the algal cells became progressively enriched in 13C during the day and the first hours of the dark period, followed by l3C depletion in the 2 h before beginning of the following Light period. The daily amplitude of the algal isotopic composition (613C), however, was <1.5%0, which demonstrates that diurnal variation in Fl3C is relatively small. : 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).