Seawater carbonate chemistry and gastropod shell composition

• Main Authors: Barclay, Kristina M, Gingras, Murray K, Packer, Stephen T, Leighton, Lindsey R
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2020
• Subjects: Animalia; Benthic animals; Benthos; Bottles or small containers/Aquaria <20 L; Calcification/Dissolution; Coast and continental shelf; Laboratory experiment; Mollusca; North Pacific; Nucella ostrina; Other studied parameter or process; Single species; Tegula funebralis; Temperate; Type; Species; Registration number of species; Uniform resource locator/link to reference; Experiment duration; Treatment; Identification; Comment; Replicate; Greyscale value; Peak height; Calcite; Aragonite; Calcite/Aragonite ratio; Alkalinity, total; Alkalinity, total, standard deviation; pH; pH, standard deviation; Salinity; Salinity, standard deviation; Temperature, water; Temperature, water, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard deviation; Fugacity of carbon dioxide water at sea surface temperature wet air; Fugacity of carbon dioxide in seawater, standard deviation; Partial pressure of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide, standard deviation; Bicarbonate ion; Bicarbonate ion, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Aragonite saturation state; Aragonite saturation state, standard deviation; Calcite saturation state; Calcite saturation state, standard deviation; Experiment; Calculated using seacarb after Nisumaa et al. 2010; Calculated using seacarb after Orr et al. 2018; Ocean Acidification International Coordination Centre OA-ICC; Pacific; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.925655; https://doi.pangaea.de/10.1594/PANGAEA.925655

Organisms, such as molluscs, that produce their hard parts from calcium carbonate are expected to show increased difficulties growing and maintaining their skeletons under ocean acidification (OA). Any loss of shell integrity increases vulnerability, as shells provide protection against predation, desiccation, and disease. Not all species show the same responses to OA, which may be due to the composition and microstructural arrangement of their shells. We explore the role of shell composition and microstructure in resisting dissolution caused by decreases in seawater pH using a combination of microCT scans, XRD analysis, and SEM imaging. Two gastropods with different shell compositions and microstructure, Tegula funebralis and Nucella ostrina, were exposed to simulated ocean acidification conditions for six months. Both species showed signs of dissolution on the exterior of their shells, but changes in density were significantly more pronounced in T. funebralis. XRD analysis indicated that the exterior layer of both shell types was made of calcite. T. funebralis may be more prone to dissolution because their outer fibrous calcite layer has more crystal edges and faces exposed, potentially increasing the surface area on which dissolution can occur. These results support a previous study where T. funebralis showed significant decreases in both shell growth and strength, but N. ostrina only showed slight reductions in shell strength, and unaffected growth. We suggest that microstructural arrangement of shell layers in molluscs, more so than their composition alone, is critical for determining the vulnerability of mollusc shells to OA. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2020) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2020-12-11.