Biomineral shell formation under ocean acidification: a shift from order to chaos

• Main Authors: Fitzer, Susan C, Chung, Peter, Maccherozzi, Francesco, Dhesi, Sarnjeet S, Kamenos, N A, Phoenix, Vernon R, Cusack, Maggie
• Format: Dataset
• Language: English
• Published: PANGAEA 2016
• Subjects: Alkalinity; total; standard deviation; Animalia; Aragonite saturation state; Benthic animals; Benthos; Bicarbonate ion; Bottles or small containers/Aquaria (<20 L); Calcite saturation state; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Coast and continental shelf; Energy; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Intensity; Laboratory experiment; Mollusca; Mytilus edulis; North Atlantic; OA-ICC; Ocean Acidification International Coordination Centre; Other studied parameter or process; Oxygen saturation; Partial pressure of carbon dioxide; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Registration number of species; Salinity; Single species; Species; Temperate; Temperature; water; Treatment; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.868601; https://doi.org/10.1594/PANGAEA.868601

Biomineral production in marine organisms employs transient phases of amorphous calcium carbonate (ACC) in the construction of crystalline shells. Increasing seawater pCO2 leads to ocean acidification (OA) with a reduction in oceanic carbonate concentration which could have a negative impact on shell formation and therefore survival. We demonstrate significant changes in the hydrated and dehydrated forms of ACC in the aragonite and calcite layers of Mytilus edulis shells cultured under acidification conditions (1000 µatm pCO2) compared to present day conditions (380 µatm pCO2). In OA conditions, Mytilus edulis has more ACC at crystalisation sites. Here, we use the high-spatial resolution of synchrotron X-ray Photo Emission Electron Microscopy (XPEEM) combined with X-ray Absorption Spectroscopy (XAS) to investigate the influence of OA on the ACC formation in the shells of adult Mytilus edulis. Electron Backscatter Diffraction (EBSD) confirms that OA reduces crystallographic control of shell formation. The results demonstrate that OA induces more ACC formation and less crystallographic control in mussels suggesting that ACC is used as a repair mechanism to combat shell damage under OA. However, the resultant reduced crystallographic control in mussels raises concerns for shell protective function under predation and changing environments.