Data for manuscript 'Ocean acidification of a coastal Antarctic marine microbial community reveals a critical threshold for CO2 tolerance in phytoplankton productivity'

It includes: - description of methods for all data collection and analyses. - marine microbial community data; Chlorophyll a concentration, particulate organic matter concentration (carbon and nitrogen), bacterial cell abundance. - phytoplankton primary productivity data; 14C-sodium bicarbonate incorporation raw data (decays per minute: DPM) and modelled productivity from photosynthesis versus irradiance (PE) curves, O2-evolution derived net community productivity, respiration, and gross primary productivity. - phytoplankton photophysiology data; community photosynthetic efficiency from PAM measurements (maximum quantum yield of PSII: Fv/Fm), PAM steady state light curve data and derived non-photochemical quenching of Chl a fluorescence (NPQ), relative electron transport rates (rETR), and effective quantum yield of PSII (delta F/Fm'). - phytoplankton carbon concentrating mechanism (CCM) data; maximum quantum yield of PSII (Fv/Fm) and effective quantum yield of PSII (∆F/Fm') from PAM measurements on size-fractionated phytoplankton samples (less than 10 microns and greater than 10 microns cells) exposed to; ethoxzolamide (EZA) which inhibits both intracellular carbonic anhydrase (iCA) and extracellular carbonic anhydrase (eCA), acetazolamide (AZA), which blocks eCA only, and a control (no inhibitor) sample. - bacterial productivity data; 14C-Leucine incorporation raw data (decays per minute: DPM) and calculated productivity.