Seawater carbonate chemistry and Pacific oyster (Crassostrea gigas) biological processes during experiments, 2011

• Main Authors: Gazeau, Frédéric, Gattuso, Jean-Pierre, Greaves, Mervyn, Elderfield, Henry, Peene, J, Heip, Carlo H R, Middelburg, Jack J
• Format: Dataset
• Language: English
• Published: PANGAEA 2011
• Subjects: Alkalinity; Gran titration (Gran; 1950); total; standard deviation; Animalia; Aragonite saturation state; Benthic animals; Benthos; Bicarbonate ion; Calcification/Dissolution; Calcite saturation state; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; partial pressure; Coast and continental shelf; Conductimeter (Radiometer CDM230); Containers and aquaria (20-1000 L or < 1 m**2); Crassostrea gigas; calcium; incorporated; larvae length; larvae shell area; length; shell area; Ocean acidification; Pacific oyster
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.769727; https://doi.org/10.1594/PANGAEA.769727

Ocean acidification, due to anthropogenic CO2 absorption by the ocean, may have profound impacts on marine biota. Calcareous organisms are expected to be particularly sensitive due to the decreasing availability of carbonate ions driven by decreasing pH levels. Recently, some studies focused on the early life stages of mollusks that are supposedly more sensitive to environmental disturbances than adult stages. Although these studies have shown decreased growth rates and increased proportions of abnormal development under low pH conditions, they did not allow attribution to pH induced changes in physiology or changes due to a decrease in aragonite saturation state. This study aims to assess the impact of several carbonate-system perturbations on the growth of Pacific oyster (Crassostrea gigas) larvae during the first 3 days of development (until shelled D-veliger larvae). Seawater with five different chemistries was obtained by separately manipulating pH, total alkalinity and aragonite saturation state (calcium addition). Results showed that the developmental success and growth rates were not directly affected by changes in pH or aragonite saturation state but were highly correlated with the availability of carbonate ions. In contrast to previous studies, both developmental success into viable D-shaped larvae and growth rates were not significantly altered as long as carbonate ion concentrations were above aragonite saturation levels, but they strongly decreased below saturation levels. These results suggest that the mechanisms used by these organisms to regulate calcification rates are not efficient enough to compensate for the low availability of carbonate ions under corrosive conditions.