I am a DPhil candidate investigating the environmental controls on plankton calcification over the last 65 million years and the relation of this process to the evolution of atmospheric CO2.
Coccolithophores and foraminifera are ocean-dwelling plankton that construct their shells from calcium carbonate in a process known as ‘calcification'. Changes in the rate of the precipitation of this biomineral alters the chemical balance in the marine carbonate system, which in turn affects how much atmospheric carbon dioxide is sequestered by the oceans.
My DPhil uses a two-pronged approach: to model the environmental conditions required to have produced the calcium carbonate observed in ocean sediments, and to analyse sediment samples in the laboratory to determine the chemical changes felt in the carbonate system. The aim is to determine which environmental parameters most strongly influence calcification, and how changes in the efficiency of calcification might influence the marine carbonate system and the air-sea exchange of CO2.
