Seawater carbonate chemistry and benthic foraminifera Ammonia sp. uranium incorporation during experiments, 2013

• Main Authors: Keul, Nina, Langer, Gerald, de Nooijer, Lennart Jan, Nehrke, Gernot, Reichart, Gert-Jan, Bijma, Jelle
• Format: Dataset
• Language: English
• Published: PANGAEA 2013
• Subjects: Alkalinity; total; Ammonia sp.; Aragonite saturation state; Benthos; Bicarbonate ion; BIOACID; Biological Impacts of Ocean Acidification; Biological sample; Biomass/Abundance/Elemental composition; BIOS; Bottles or small containers/Aquaria (<20 L); Calcite saturation state; Calculated; see reference(s); Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Chromista; Coast and continental shelf; Coefficient; Conductivity and pH meter; pH/Cond 340i (WTW; Weilheim); EPOCA; European Project on Ocean Acidification; Experimental treatment; Foraminifera; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Heterotrophic prokaryotes; Keul-2011-Ammonia; Laboratory experiment; Mediterranean Sea Acidification in a Changing Climate; MedSeA; North Atlantic; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Photometrically using autoanalyzer QUAATRO; Salinity; Single species; Temperate; Temperature; water; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.821210; https://doi.org/10.1594/PANGAEA.821210

The chemical and isotopic composition of foraminiferal shells (so-called proxies) reflects the physico-chemical properties of the seawater. In current day paleoclimate research, the reconstruction of past seawater carbonate system to infer atmospheric CO2 concentrations is one of the most pressing challenges and a variety of proxies have been investigated, such as foraminiferal U/Ca. Since in natural seawater and traditional CO2 perturbation experiments, the carbonate system parameters co-vary, it is not possible to determine the parameter of the carbonate system causing e.g. changes in U/Ca, complicating the use of the latter as a carbonate system proxy. We overcome this problem, by culturing the benthic foraminifer Ammonia sp. at a range of carbonate chemistry manipulation treatments. Shell U/Ca values were determined to test sensitivity of U incorporation to various parameters of the carbonate system. We argue that CO3 is the parameter affecting the U/Ca ratio and consequently, the partitioning coefficient for U in Ammonia sp DU. We can confirm the strong potential of foraminiferal U/Ca as a CO3 proxy.