No detectable effect of CO2 on elemental stoichiometry of Emiliania huxleyi in nutrient-limited, acclimated continuous cultures

Marine Ecology Progress Series

Markus Schartau¹  Cindy Lee¹  Sonja Endres¹  Anja Engel¹  Tiantian Tang¹  Carolina Cisternas Novoa¹  Mascha Wurst¹ 

关键词: Acidification;    Cocolithophores;    Element composition;    Nutrient limitation;    Chemostats;   

DOI  :  10.3354/meps10824

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: Effects of CO₂ concentration on elemental composition of the coccolithophore Emiliania huxleyi were studied in phosphorus-limited, continuous cultures that were acclimated to experimental conditions for 30 d prior to the first sampling. We determined phytoplankton and bacterial cell numbers, nutrients, particulate components like organic carbon (POC), inorganic carbon (PIC), nitrogen (PN), organic phosphorus (POP), transparent exopolymer particles (TEP), as well as dissolved organic carbon (DOC) and nitrogen (DON), in addition to carbonate system parameters at CO₂ levels of 180, 380 and 750 µatm. No significant difference between treatments was observed for any of the measured variables during repeated sampling over a 14 d period. We considered several factors that might lead to these results, i.e. light, nutrients, carbon overconsumption and transient versus steady-state growth. We suggest that the absence of a clear CO₂ effect during this study does not necessarily imply the absence of an effect in nature. Instead, the sensitivity of the cell towards environmental stressors such as CO₂ may vary depending on whether growth conditions are transient or sufficiently stable to allow for optimal allocation of energy and resources. We tested this idea on previously published data sets where PIC and POC divided by the corresponding cell abundance of E. huxleyi at various pCO₂ levels and growth rates were available.

【 授权许可】

Unknown