Seawater carbonate chemistry and acid-base physiology, skeleton properties, and metal contamination in two echinoderms

• Main Authors: Di Giglio, Sarah, Agüera, Antonio, Pernet, Philippe, M'Zoudi, Saloua, Angulo-Preckler, Carlos, Avila, Conxita, Dubois, Philippe
• Format: Dataset
• Language: English
• Published: PANGAEA 2020
• Subjects: Acid-base regulation; Alkalinity; total; standard deviation; Animalia; Antarctic; Aragonite saturation state; Arm length; Benthic animals; Benthos; Bicarbonate ion; Cadmium; Calcite saturation state; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Calculated using seacarb after Orr et al. (2018); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Characteristic stress; CO2 vent; Coast and continental shelf; Coelomic fluid; Antarc*; Antarctic Peninsula; Deception Island; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.929722; https://doi.org/10.1594/PANGAEA.929722

Antarctic surface waters are expected to be the first to experience severe ocean acidification (OA) with carbonate undersaturation and large decreases in pH forecasted before the end of this century. Due to the long stability in environmental conditions and the relatively low daily and seasonal variations to which they are exposed, Antarctic marine organisms, especially those with a supposedly poor machinery to eliminate CO2 and protons and with a heavily calcified skeleton like echinoderms, are hypothesized as highly vulnerable to these environmental shifts. The opportunities offered by the natural pH gradient generated by vent activities in Deception Island caldera, Western Antarctic Peninsula, were used to investigate for the first time the acid-base physiologies, the impact of OA on the skeleton and the impact of pH on metal accumulation in the Antarctic sea star Odontaster validus and sea urchin Sterechinus neumayeri. The two species were sampled in four stations within the caldera, two at pH (total scale) 8.0- 8.1 and two at reduced pH 7.8. Measured variables were pH, alkalinity, and dissolved inorganic carbon of the coelomic fluid; characteristic fracture force, stress and Young's modulus using Weibull statistics and Cd, Cu, Fe, Pb and Zn concentrations in the integument, gonads and digestive system. Recorded acid-base characteristics of both studied species fit in the general picture deduced from temperate and tropical sea stars and sea urchins but conditions and possibly confounding factors, principally food availability and quality, in the studied stations prevented definitive conclusions. Reduced seawater pH 7.8 and metals had almost no impact on the skeleton mechanical properties of the two investigated species despite very high Cd concentrations in O. validus integument. Reduced pH was correlated to increased contamination by most metals but this relation was weak. Translocation and caging experiments taking into account food parameters are proposed to better understand future processes linked to ...