Assessing the impact of different carbonate system parameters on benthic foraminifera from controlled growth experiments

• Published in: Chemical Geology
• Main Authors: Mojtahid, M., Depuydt, P., Mouret, A., Le Houedec, S., Fiorini, S., Chollet, S., Massol, F., Dohou, F., Filipsson, H.L., Boer, W., Reichart, G.-J., Barras, C.
• Other Authors: Laboratoire de Planétologie et Géosciences UMR_C 6112 (LPG), Le Mans Université (UM)-Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), Université de Genève = University of Geneva (UNIGE), CEREEP-Ecotron Ile de France (UMS 3194), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Skane University Hospital Lund, Royal Netherlands Institute for Sea Research (NIOZ), Department of Earth Sciences, Faculty of Geosciences, Utrecht University, CNRS-INSU-LEFE-IMAGO-CYBER program (STING project)Region Pays de Loire programs (Rising Star project TANDEM)Ecotron Ile De France incentive research projects (ECOFOR project)French Ministry of Higher Education and ResearchSwedish Research Council VR (2017-04190)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: Ocean acidification; Biomineralisation; Carbonate system; Culture experiment; Sr/Ca; Benthic foraminifera; [SDU]Sciences of the Universe [physics]; [CHIM]Chemical Sciences; [SDV]Life Sciences [q-bio]
• Online Access: https://hal.science/hal-04015882; https://hal.science/hal-04015882/document; https://hal.science/hal-04015882/file/Mojtahid_et_al_2023_version_auteur.pdf; https://doi.org/10.1016/j.chemgeo.2023.121396

International audience Insights into past marine carbon cycling and water mass properties can be obtained by means of geochemical proxies calibrated through controlled laboratory experiments with accurate seawater carbonate system (C-system) manipulations. Here, we explored the use of strontium/calcium ratio (Sr/Ca) of the calcite shells of benthic foraminifera as a potential seawater C-system proxy through a controlled growth experiment with two deep-sea species (Bulimina marginata and Cassidulina laevigata) and one intertidal species (Ammonia T6). To this aim, we used two experimental setups to decouple as much as possible the individual components of the carbonate system, i.e., changing pH at constant dissolved inorganic carbon (DIC) and changing DIC at constant pH. Four climatic chambers were used with different controlled concentrations of atmospheric pCO2 (180 ppm, 410 ppm, 1000 ppm, 1500 ppm). Our results demonstrated that pH did not influence the survival and growth of the three species. However, low DIC conditions (879 µmol kg-1) negatively affected B. marginata and C. laevigata through reduced growth, whereas no effect was observed for Ammonia T6. Our results also showed that Sr/Ca was positively correlated with total Alkalinity (TA), DIC and bicarbonate ion concentration ([HCO3-]) for Ammonia T6 and B. marginata; i.e., DIC and/or [HCO3-] were the main controlling factors. For these two species, the regression models were coherent with published data (existing so far only for Ammonia T6) and showed overall similar slopes but different intercepts, implying species-specific effects. Furthermore, the Sr/Ca-Csystem relationship was not impacted by ontogenetic trends between chamber stages, which is a considerable advantage for paleo-applications. This applied particularly to Ammonia T6 that calcified many chambers compared to the two other species. However, no correlation with any of the C-system parameters was observed for Sr/Ca in C. laevigata. This might imply either a strong species-specific effect ...