Influence of Environmental Factors over the Incorporation of U, Cd, and Minor Metals into Foraminiferal Calcite: Results of Summer 2004 Culture Experiments

During the summer of 2004, we conducted laboratory culture experiments with planktonic foraminifera (O. universa and G. bulloides) to constrain the relationships between U, Cd, Mg, and Sr and environmental factors (temperature, salinity, carbonate ion concentration, and light levels). In order to test the hypothesis that photosynthesis by algal symbionts influences U incorporation through its effect on local pH, we cultured O. universa (a symbiont-bearing species) under low light conditions in seawater modified to produce a range of carbonate ion concentrations. We will compare this curve to one we generated in previous experiments using O. universa cultured under high light conditions. We also cultured G. bulloides (a symbiont-free species) in seawater of variable carbonate. In addition, we conducted experiments to evaluate the influence of salinity and temperature on U in G. bulloides, and the influence of salinity and temperature in O. universa. Finally, we evaluated the influence of temperature on Cd in G. bulloides. We will report the results of these experiments at the Fall AGU Meeting.