S. Burkhardt, U. Riebesell-1997
Marine Ecology Progress Series, 155 : 67-76 (from Current Contents)
Abstract:
The effect of variable CO2 concentrations on the elemental composition (C:N:P) of marine diatoms was investigated in 2 strains of Skeletonema costatum (Grev.) Cleve. Five or 6 concentrations of dissolved molecular carbon dioxide (CO2 (aq)), ranging from 0.5 to 39 mu mol/l, were applied in dilute batch cultures. In both strains, elemental ratios were clearly dependent on (CO2 (aq)). With decreasing CO2 concentrations, a decline in C:P and N:P and an increase in C:N was observed. The close correlation between C:P or N:P and ((O2 (aq)) corresponded to a ca 45 to 65% decrease in elemental ratios from highest (greater than or equal to 30 mu mol/l) to lowest (ca 1 mu mol/l) CO2 concentrations. C:N at low (CO2 (aq)) was up to 24% higher than at high (CO2 (aq)). To date, the elemental composition of marine phytoplankton has been considered to be independent of CO2 availability. If dependency of the C:N:P ratio on (CO2 (aq)) proves to be a general phenomenon in marine phytoplankton, changes in the elemental composition may be expected in response to the currently observed increase in partial pressure of atmospheric CO2.
(Alfred Wegener Inst. Polar & Marine Res., Handelshafen 12, D-27570 Bremerhaven, Germany)