We assessed responses of Arctic Isochrysis sp. grown under a matrix of temperature (2°C vs. 6°C), light intensity (55 vs. 160 μ mol photons m −2 s −1 ) and pCO 2 (400 vs. 1000 μ atm CO 2 ). Next to acclimation parameters (growth rates, particulate and dissolved organic C and N, chlorophyll a content), we measured physiological processes in vivo (electron transport rates and net photosynthesis) using fast‐repetition rate fluoro...

Microbial metabolism influences rates of net community production (NCP), exerting a direct biological control on marine oxygen and carbon fluxes. In the Arctic, it is increasingly important to understand and quantify this process, as ecological and oceanographic conditions shift due to changing climate. Here, we describe potential ecological links between pelagic microbial diversity and an NCP precursor, biological oxygen util...

Ocean warming is especially pronounced in the Arctic, and phytoplankton will face thermodynamically driven changes in their physiology, potentially pushing them beyond their thermal optimum. We assessed temperature responses of multiple functional traits over their entire thermal window (growth rates, quotas of particulate organic carbon, nitrogen, and chlorophyll a , as well as photophysiological parameters) in three differen...

We assessed the responses of solitary cells of Arctic Phaeocystis pouchetii grown under a matrix of temperature (2°C vs. 6°C), light intensity (55 vs. 160 μ mol photons m −2 s −1 ) and pCO 2 (400 vs. 1000 μ atm CO 2 , i.e., 40.5 vs. 101.3 Pa). Next to acclimation parameters (growth rates, particulate and dissolved organic C and N, Chlorophyll a content), we measured physiological processes in vivo (electron transport rates and...

Sea ice retreat, changing stratification, and ocean acidification are fundamentally changing the light availability and physico‐chemical conditions for primary producers in the Arctic Ocean. However, detailed studies on ecophysiological strategies and performance of key species in the pelagic and ice‐associated habitat remain scarce. Therefore, we investigated the acclimated responses of the diatoms Thalassiosira hyalina and M...

The coccolithophore Emiliania huxleyi is a microalga with biogeochemical and biotechnological relevance, due to its high abundance in the ocean and its ability to form intricate calcium carbonate structures. Depletion of macronutrients in oceanic waters is very common and will likely enhance with advancing climate change. We present the first comprehensive metabolome study analyzing the effect of phosphorus (P) and nitrogen (N...

The effects of ocean acidification on the life‐cycle stages of the coccolithophore Emiliania huxleyi and their modulation by light were examined. Calcifying diploid and noncalcifying haploid cells (Roscoff culture collection strains 1216 and 1217) were acclimated to present‐day and elevated CO 2 partial pressures (P CO 2 ; 38.5 vs. 101.3 Pa, i.e., 380 vs. 1000 µatm) under low and high light (50 vs. 300 µmol photons m −2 s −1 )...