Seawater carbonate chemistry and carbon and oxygen isotopes during experiments with planktonic foraminifera Orbulina universa and Globigerina bulloides, 1997, supplement to: Spero, Howard J; Bijma, Jelle; Lea, David W; Bemis, E B (1997): Effect of seawater carbonate concentration on foraminiferal carbon and oxygen isotopes. Nature, 390(6659), 497-500

• Main Authors: Spero, Howard J, Bijma, Jelle, Lea, David W, Bemis, E B
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 1997
• Subjects: Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria <20 L; Chromista; Coast and continental shelf; Foraminifera; Globigerina bulloides; Heterotrophic prokaryotes; Laboratory experiment; North Pacific; Orbulina universa; Pelagos; Single species; Temperate; Experimental treatment; Sample ID; Salinity; Temperature, water; Carbonate system computation flag; pH; Alkalinity, total; Carbon, inorganic, dissolved; Carbonate ion; Carbon dioxide; Bicarbonate ion; Partial pressure of carbon dioxide water at sea surface temperature wet air; Fugacity of carbon dioxide water at sea surface temperature wet air; Aragonite saturation state; Calcite saturation state; Foraminifera, planktic δ13C; Foraminifera, planktic δ18O; Experiment; Calculated using seacarb after Nisumaa et al. 2010; Titration potentiometric; Calculated; Isotope ratio mass spectrometry; European network of excellence for Ocean Ecosystems Analysis EUR-OCEANS; European Project on Ocean Acidification EPOCA; Ocean Acidification International Coordination Centre OA-ICC; South Atlantic in Late Quaternary Reconstruction of Budget and Currents SFB261; Pacific; Shackleton; Ocean acidification; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.721923; https://doi.pangaea.de/10.1594/PANGAEA.721923

Stable oxygen and carbon isotope measurements on biogenic calcite and aragonite have become standard tools for reconstructing past oceanographic and climatic change. In aquatic organisms, 18O/16O ratios in the shell carbonate are a function of the ratio in the sea water and the calcification temperature (Epstein et al., 1953). In contrast, 13C/12C ratios are controlled by the ratio of dissolved inorganic carbon in sea water and physiological processes such as respiration and symbiont photosynthesis (Spero et al., 1991, doi:10.1029/91PA02022). These geochemical proxies have been used with analyses of foraminifera shells to reconstruct global ice volumes (Shackleton and Opdyke, 1973, doi:10.1016/0033-5894(73)90052-5), surface and deep ocean temperatures (Broecker, 1986, doi:10.1016/0033-5894(86)90087-6; Labeyrie et al., 1987, doi:10.1038/327477a0), ocean circulation changes (Duplessy et al., 1988, doi:10.1029/PA003i003p00343) and glacial-interglacial exchange between the terrestrial and oceanic carbon pools (Sackleton, 1977). Here, we report experimental measurements on living symbiotic and non-symbiotic plankton foraminifera (Orbulina universa and Globigerina bulloides respectively) showing that the 13C/12C and 18O/16O ratios of the calcite shells decrease with increasing seawater [CO3 2-]. Because glacial-period oceans had higher pH and [CO3 2-] than today (Sanyal et al., 1995, doi:10.1038/373234a0), these new relationships confound the standard interpretation of glacial foraminiferal stable-isotope data. In particular, the hypothesis that the glacial-interglacial shift in the 13C/12C ratio was due to a transfer of terrestrial carbon into the ocean(Shackleton ,1977) can be explained alternatively by an increase in ocean alkalinity (Lea et al., 1996). A carbonate-concentration effect could also help explain some of the extreme stable-isotope variations during the Proterozoic and Phanerozoic aeons (Kaufman et al., 1993, doi:10.1016/0012-821X(93)90254-7). : 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).