TY - DATA ID - rokitta2012scca T1 - Seawater carbonate chemistry and effects of CO2 and their modulation by light in the life-cycle stages of the coccolithophore Emiliania huxleyi strains RCC 1216 and 1217 during experiments, 2012 AU - Rokitta, Sebastian D AU - Rost, Björn PY - 2012/03/12/ T2 - Supplement to: Rokitta, SD; Rost, B (2012): Effects of CO2 and their modulation by light in the life-cycle stages of the coccolithophore Emiliania huxleyi. Limnology and Oceanography, 57(2), 607-618, https://doi.org/10.4319/lo.2012.57.2.0607 PB - PANGAEA DO - 10.1594/PANGAEA.777432 UR - https://doi.org/10.1594/PANGAEA.777432 N2 - The effects of ocean acidification on the life-cycle stages of the coccolithophore Emiliania huxleyi and their by light were examined. Calcifying diploid and noncalcifying haploid cells (Roscoff culture collection 1216 and 1217) were acclimated to present-day and elevated CO2 partial pressures (PCO2; 38.5 vs. 101.3 Pa, ., 380 vs. 1000 matm) under low and high light (50 vs. 300 mmol photons m-2 s-1). Growth rates as well as quotas and production rates of C and N were measured. Sources of inorganic C for biomass buildup were using a 14C disequilibrium assay. Photosynthetic O2 evolution was measured as a function of dissolved inorganic C and light by means of membrane-inlet mass spectrometry. The diploid stage responded to elevated PCO2 by shunting resources from the production of particulate inorganic C toward organic C yet keeping the production of total particulate C constant. As the effect of ocean acidification was stronger under low light, the diploid stage might be less affected by increased acidity when energy availability is high. The haploid stage maintained elemental composition and production rates under elevated PCO2. Although both life-cycle stages involve different ways of dealing with elevated PCO2, the responses were generally modulated by energy availability, being typically most pronounced under low light. Additionally, PCO2 responses resembled those induced by high irradiances, indicating that ocean acidification affects the interplay between energy-generating processes (photosynthetic light reactions) and processes competing for energy (biomass buildup and calcification). A conceptual model is put forward explaining why the magnitude of single responses is determined by energy availability. KW - Biomass/Abundance/Elemental composition KW - Bottles or small containers/Aquaria (<20 L) KW - Calcification/Dissolution KW - Chromista KW - Emiliania huxleyi KW - Growth/Morphology KW - Haptophyta KW - Laboratory experiment KW - Laboratory strains KW - Light KW - Not applicable KW - Pelagos KW - Phytoplankton KW - Primary production/Photosynthesis KW - Single species ER -