Seawater carbonate chemistry, calcification and respiration duirng experiments with a pteropod Creseis acicula, 2010

• Main Authors: Comeau, Steeve, Gattuso, Jean-Pierre, Jeffree, Ross, Gazeau, Frédéric
• Format: Dataset
• Language: English
• Published: PANGAEA 2010
• Subjects: **45Ca incorporation; Alkalinity; total; standard deviation; Alkalinity anomaly technique (Smith and Key; 1975); Ammonium; excretion; Aragonite saturation state; Bicarbonate ion; Calcification rate; Calcification rate of calcium carbonate; Calcite saturation state; Calculated; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; partial pressure; Colorimetric technique (Koroleff 1983) and a JenWay 6310 (Staffordshire; UK) flu; EPOCA; EUR-OCEANS; European network of excellence for Ocean Ecosystems Analysis; European Project on Ocean Acidification; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.754858; https://doi.org/10.1594/PANGAEA.754858

Among marine calcifiers, shelled pteropods are expected to be particularly sensitive to ocean acidification, generated by the uptake of anthropogenic CO2 by the ocean, and the associated decrease of the seawater saturation state with respect to aragonite (omega aragonite). The few available studies have mostly focused on polar species although pteropods are also important components of temperate and tropical ecosystems. It is also unknown which parameter of the carbonate system controls calcification. Specimens of the temperate Mediterranean species Creseis acicula were maintained under seven different conditions of the carbonate chemistry, obtained by manipulating pH and total alkalinity, with the goal to disentangle the effects of pH and omega aragonite. Respiration, excretion as well as rates of net and gross calcification were not directly affected by a decrease in pH but decreased significantly with a decrease of omega aragonite. The decrease of gross calcification rates is consistent with that reported for polar species. Although the organisms were apparently able to maintain gross calcification rates under slightly undersaturated aragonite conditions, the clear net dissolution signal observed below saturation suggests that they are not able to build a shell in seawater corrosive to aragonite. The decrease in respiration and excretion, and the low O:N molar ratio, could be due to the short time that the organisms were allowed to acclimatize to their new environment.