Keywords: Acid-base regulation; Advanced Force Gauge (AFG), Mecmesin, 50 N; Alkalinity, total; Animalia; Aragonite saturation state; Behaviour; Benthic animals; Benthos; Bicarbonate ion; Biomass, dry mass; Biomass, shell, dry mass; Biomass, shell, wet mass; Biomass, wet mass; Blood gas analyser, Eschweiler, MT 33; Calcite saturation state; Calculated; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Condition index; Containers and aquaria (20-1000 L or 〈 1 m**2); Coulometric titration; Force; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Gas chromatography, Agilent 6890 N GC System, Agilent Technologies; Growth/Morphology; Height; Incubation duration; Laboratory experiment; Length; Mollusca; Muscle, diameter; Muscle, dry mass; Muscle, wet mass; Muscle condition index; Net aerobic scope; North Atlantic; Number of claps; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Pecten maximus; Pecten maximus, haemolymph, bicarbonate ion; Pecten maximus, haemolymph, carbon dioxide partial pressure; Pecten maximus, haemolymph, oxygen partial pressure; Pecten maximus, haemolymph, pH; Pecten maximus, haemolymph, total carbon dioxide; pH; pH, standard deviation; Potentiometric; Respiration; Respiration rate, oxygen; Salinity; Salinity, standard deviation; Salinometer, WTW ProfiLine Cond 1970i; Sample code/label; Single species; Species; Temperate; Temperature; Temperature, standard deviation; Temperature, water; Temperature probe; TP; Treatment; Vernier caliper; Weighted; Width