FIGURE 3. Scanning electron microscopy (SEM) photographs of coccolithophorids under different CO2 concentrations.

From the following article:

Reduced calcification of marine plankton in response to increased atmospheric CO2

Ulf Riebesell, Ingrid Zondervan, Björn Rost, Philippe D. Tortell, Richard E. Zeebe and François M. M. Morel

Nature 407, 364-367(21 September 2000)



a, b, d, e, Emiliania huxleyi; and c, f, Gephyrocapsa oceanica collected from cultures incubated at [CO2] approximately 12 micromol l-1 (a c) and at [CO2] approximately 30–33 micromol l-1 (df), corresponding to pCO2 levels of about 300 p.p.m.v. and 780–850 p.p.m.v., respectively. Scale bars represent 1 microm. Note the difference in the coccolith structure (including distinct malformations) and in the degree of calcification of cells grown at normal and elevated CO2 levels. Pictures are selected from a large set of SEM photographs to depict the general trend in coccolith calcification. As the culture medium was super-saturated with respect to calcium carbonate under all experimental conditions, post-formation calcite dissolution is not expected to have occurred.