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The biological imprint of calcification in foraminifera
Project leader: Prof. dr. J. Bijma
Researcher(s): Dr. G. Langer
Starting date: 01-04-2010

Abstract
Foraminifera are marine unicellular organisms that produce tests (i.e. shells) of calcium carbonate. After an individual's death, its test can get preserved in the ocean's sediment and constitute therefore one of the most popular tools to reconstruct Earth's climate. This is possible since the chemical composition of their calcite is determined by the environment in which they grow: at higher temperatures, for example, more magnesium is incorporated in the CaCO3 matrix. The reliability of the reconstructions that are based on correlations between environmental parameters and calcite chemistry can be improved considerably after quantification of the biological influence of the foraminfiera themselves on calcite precipitation. This could, explain the inter-species variability in temperature-magnesium correlations. With this project we analyze how living foraminifera take up seawater and concentrate calcium and inorganic carbon and expulse Mg. These ions will be tracked until their involvement in calcite precipitation. Using new techniques the formed calcite will be analyzed in order to relate the chemical composition to ultrastructures of the foraminiferal tests.

Publications
Langer G, De Nooijer LJ, Oetjen K (2010). On the role of the cytoskeleton in coccolith morphogenesis: The effect of cytoskeleton inhibitors. PHYCOLOGY46: 1252-1256.
Darwin Center authors: Langer G., de Nooijer L.J.

Hoppe, C. J. M. , Langer, G. , Rokitta, S. D. , Wolf-Gladrow, D. A. and Rost, B. (2012). Implications of observed inconsistencies in carbonate chemistry measurements for ocean acidification studies. Biogeosciences9: 2401-2405.
Darwin Center authors: Langer G.

Stoll, H. , Langer, G. , Shimizu, N. and Kanamaru, K. (2012). B/Ca in coccoliths and relationship to calcification vesicle pH and dissolved inorganic carbon concentrations. Geochimica et Cosmochimica Acta80: 143-157.
Darwin Center authors: Langer G.

Langer, G. , Oetjen, K. and Brenneis, T. (2012). Calcification of Calcidiscus leptoporus under nitrogen and phosphorus limitation. Journal of Experimental Marine Biology and Ecology413: 131-137.
Darwin Center authors: Langer G.

Ziveri, P. , Thoms, S. , Probert, I. , Geisen, M. and Langer, G. (2012). A universal carbonate ion effect on stable oxygen isotope ratios in unicellular planktonic calcifying organisms. Biogeosciences9: 1025-1032.
Darwin Center authors: Langer G.

Langer, G., Oetjen, K., Brenneis, T. (2012). On culture artefacts in coccolith morphology. Helgoland Marine Research
Darwin Center authors: Langer G.