Keywords: Acanthoica quattrospina; Aligosphaera robusta; Alisphaera extenta; Alisphaera gaudii; Alkalinity, total; Alkalinity, total, standard error; Ammonia; Ammonia, standard deviation; Aragonite saturation state; Arctic; Bicarbonate ion; Biomass/Abundance/Elemental composition; Braarudosphaera bigelowii; Calcidiscus leptoporus; Calcification/Dissolution; Calcification rate, standard deviation; Calcification rate of calcium carbonate; Calciopappus caudatus; Calciosolenia murrayi; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Calyptrosphaera sphaeroidea; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard error; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Chlorophyll a; Coast and continental shelf; Coccolithophoridae, total; Coccolithus pelagicus; Community composition and diversity; Corisphaera gracilis; Coulometry; CTD; DATE/TIME; DEPTH, water; Depth of the euphotic zone; Emiliania huxleyi; Emiliania huxleyi, coccoliths, detached; Entire community; EPOCA; EUR-OCEANS; European network of excellence for Ocean Ecosystems Analysis; European Project on Ocean Acidification; Field observation; Florisphaera profunda; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gephyrocapsa oceanica; Helicosphaera carteri; Helladosphaera cornifera; Homozygosphaera vercelii; Lachat QuickChem 8500 flow injection autoanalyser; LATITUDE; Light; LONGITUDE; Micro-diffusion technique of Paasche & Brubak 1994 modified by Balch etal 2000; Nitrate and Nitrite; Nitrate and Nitrite, standard deviation; North Atlantic; OA-ICC; Ocean Acidification International Coordination Centre; Open ocean; Ophiaster formosus; Ophiaster hydroideus; Ophiaster sp.; Palusphaera vandelii; Pappomonas sp.; Pappomonas virgulosa; Papposphaera arctica; Papposphaera lepida; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pelagos; pH; Phosphate; Phosphate, standard deviation; Phytoplankton, unknown; Pigments, Turner fluorometer; Polar; Primary production/Photosynthesis; Primary production of carbon, standard deviation; Primary production of carbon per day; Radiation, photosynthetically active; Rhabdosphaera xiphos; Salinity; Sample ID; Saturnulus helianthiformis; Scanning electron microscope (Leo 1450VP, Carl Zeiss) with software SmartSEM; Semi-closed-cell titration (Dickson et al. 2007); Silicate; Silicate, standard deviation; Sphaerocalyptra sp.; Syracosphaera bannockii; Syracosphaera borealis; Syracosphaera corolla; Syracosphaera exigua; Syracosphaera marginiporata; Syracosphaera molischii; Syracosphaera nana; Syracosphaera ossa; Syracosphaera sp.; Syracosphaera tumularis; Temperate; Temperature, water; Wigwamma sp.