Seawater carbonate chemistry and adhesion and shell formation of the Barnacle Amphibalanus amphitrite

• Main Authors: Nardone, Jessica A, Patel, Shrey, Siegel, Kyle R, Tedesco, Dana, McNicholl, Conall G, O'Malley, Jessica, Herrick, Jack, Metzler, Rebecca A, Orihuela, Beatriz, Rittschof, Daniel, Dickinson, Gary H
• Format: Dataset
• Language: English
• Published: PANGAEA - Data Publisher for Earth & Environmental Science 2018
• Subjects: Amphibalanus amphitrite; Animalia; Arthropoda; Benthic animals; Benthos; Biomass/Abundance/Elemental composition; Bottles or small containers/Aquaria <20 L; Coast and continental shelf; Growth/Morphology; Laboratory experiment; North Atlantic; Other studied parameter or process; Single species; Type; Species; Registration number of species; Uniform resource locator/link to reference; Experiment duration; Treatment; Tissue, dry mass; Dry mass, standard error; Replicates; Adhesive strength; Adhesive strength, standard error; Shell, dry mass; Height; Height, standard error; Crystallinity; Crystallinity, standard error; Atomic disorder; Atomic disorder, standard error; Area; Area, standard error; Thickness; Thickness, standard error; Microhardness; Microhardness, standard error; Crack propagation; Crack propagation, standard error; Calcite crystal area; Calcite crystal area, standard error; Calcium; Calcium, standard error; Magnesium; Magnesium, standard error; pH; pH, standard deviation; Temperature, water; Temperature, water, standard deviation; Salinity; Salinity, standard deviation; Partial pressure of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide, standard deviation; Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Bicarbonate ion; Bicarbonate ion, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Alkalinity, total; Alkalinity, total, standard deviation; Calcite saturation state; Calcite saturation state, 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; Aragonite saturation state; Aragonite saturation state, standard deviation; Potentiometric; Calculated using CO2calc; Potentiometric titration; Calculated using seacarb after Nisumaa et al. 2010; Calculated using seacarb after Orr et al. 2018; Ocean Acidification International Coordination Centre OA-ICC; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.922978; https://doi.pangaea.de/10.1594/PANGAEA.922978

Barnacles are dominant members of marine intertidal communities. Their success depends on firm attachment provided by their proteinaceous adhesive and protection imparted by their calcified shell plates. Little is known about how variations in the environment affect adhesion and shell formation processes in barnacles. Increased levels of atmospheric CO2 have led to a reduction in the pH of ocean waters (i.e., ocean acidification), a trend that is expected to continue into the future. Here, we assessed if a reduction in seawater pH, at levels predicted within the next 200 years, would alter physiology, adhesion, and shell formation in the cosmopolitan barnacle Amphibalanus (=Balanus) amphitrite. Juvenile barnacles, settled on silicone substrates, were exposed to one of three static levels of pHT, 8.01, 7.78, or 7.50, for 13 weeks. We found that barnacles were robust to reduced pH, with no effect of pH on physiological metrics (mortality, tissue mass, and presence of eggs). Likewise, adhesive properties (adhesion strength and adhesive plaque gross morphology) were not affected by reduced pH. Shell formation, however, was affected by seawater pH. Shell mass and base plate area were higher in barnacles exposed to reduced pH; barnacles grown at pHT 8.01 exhibited approximately 30% lower shell mass and 20% smaller base plate area as compared to those at pHT 7.50 or 7.78. Enhanced growth at reduced pH appears to be driven by the increased size of the calcite crystals that comprise the shell. Despite enhanced growth, mechanical properties of the base plate (but not the parietal plates) were compromised at the lowest pH level. Barnacle base plates at pHT 7.50 broke more easily and crack propagation, measured through microhardness testing, was significantly affected by seawater pH. Other shell metrics (plate thickness, relative crystallinity, and atomic disorder) were not affected by seawater pH. Hence, a reduction in pH resulted in larger barnacles but with base plates that would crack more readily. It is yet to be determined if such changes would alter the survival of A. amphitrite in the field, but changes in the abundance of this ecologically dominant species would undoubtedly affect the composition of biofouling communities. : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2019) 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 2020-09-18.