Caraco, N. Institute of Ecosystem Studies, caracon@ecostudies.org
Lampman, G. Institute of Ecosystem Studies, lampmang@ecostudies.org

 
CO2 INDUCED CHANGES IN C:N:P RATIOS OF MARINE DIATOMS: A LINK TO OCEANIC C STORAGE?
 
It is well known that N and P availability can impact the stoichiometry of organic matter produced by phytoplankton. The impact of CO2 on this stoichiometry is, however, rarely considered. To test for this possible link we grew marine diatoms under different CO2 concentrations. Our results indicate that the effect of CO2 on phytoplankton net production and stoichiometric shifts are closely aligned and that larger diatoms appear to be more strongly impacted than are smaller ones. For the largest diatom we investigated (Ditylum), growth at 4, 12, and 36 uM CO2 resulted in C:N of particulate production of 6, 10, and 20, respectively. Over the same CO2 range C:N of total carbon production (particulate + dissolved) increased from 9 to near 30. These results suggest a potentially important biotic feedback to global CO2 increases.
 
Day: Wednesday, Feb. 3
Time: 04:15 - 04:30pm
Location: Sweeney Center
 
Code: SS49WE0415S