Seawater carbonate chemistry and physiological performance parameters of Carcinus maenas under respective incubation conditions

• Main Authors: Maus, Bastian, Bock, Christian, Pörtner, Hans-Otto
• Format: Dataset
• Language: English
• Published: PANGAEA 2018
• Subjects: Acid-base regulation; Alkalinity; total; standard deviation; Animalia; Aragonite saturation state; Arthropoda; Behaviour; Benthic animals; Benthos; Bicarbonate; Bicarbonate ion; Calcite saturation state; Calcium ion; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Carcinus maenas; Chloride; Coast and continental shelf; Containers and aquaria (20-1000 L or < 1 m**2); Difference; EXP; Experiment; Experiment duration; Factorial aerobic scope; Flow rate; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Haemolymph; partial pressure of carbon dioxide; total carbon dioxide; Heart rate; Hydrogen ion concentration; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.892815; https://doi.org/10.1594/PANGAEA.892815

Ocean acidification causes an accumulation of CO2 in marine organisms and leads to shifts in acid-base parameters. Acid-base regulation in gill breathers involves a net increase of internal bicarbonate levels through transmembrane ion exchange with the surrounding water. Successful maintenance of body fluid pH depends on the functional capacity of ion-exchange mechanisms and associated energy budget. For a detailed understanding of the dependence of acid-base regulation on water parameters, we investigated the physiological responses of the shore crab Carcinus maenas to 4 weeks of ocean acidification [OA, P(CO2)w = 1800 µatm], at variable water bicarbonate levels, paralleled by changes in water pH. Cardiovascular performance was determined together with extra-(pHe) and intracellular pH (pHi), oxygen consumption, haemolymph CO2 parameters, and ion composition. High water P(CO2) caused haemolymph P(CO2) to rise, but pHe and pHi remained constant due to increased haemolymph and cellular [HCO3-]. This process was effective even under reduced seawater pH and bicarbonate concentrations. While extracellular cation concentrations increased throughout, anion levels remained constant or decreased. Despite similar levels of haemolymph pH and ion concentrations under OA, metabolic rates, and haemolymph flow were significantly depressed by 40 and 30%, respectively, when OA was combined with reduced seawater [HCO3-] and pH. Our findings suggest an influence of water bicarbonate levels on metabolic rates as well as on correlations between blood flow and pHe. This previously unknown phenomenon should direct attention to pathways of acid-base regulation and their potential feedback on whole-animal energy demand, in relation with changing seawater carbonate parameters.