Publication Date:
2024-03-15
Description:
Ocean acidification (OA) is a major threat to marine ecosystems, particularly coral reefs which are heavily reliant on calcareous species. OA decreases seawater pH and calcium carbonate saturation state (Omega), and increases the concentration of dissolved inorganic carbon (DIC). Intense scientific effort has attempted to determine the mechanisms via which ocean acidification (OA) influences calcification, led by early hypotheses that calcium carbonate saturation state (Omega) is the main driver. We grew corals and coralline algae for 8 to 21 weeks, under treatments where the seawater parameters Omega, pH and DIC were manipulated to examine their differential effects on calcification rates and calcifying fluid chemistry (Omega cf, pHcf, and DICcf). Here, using long duration experiments, we provide geochemical evidence that differing physiological controls on carbonate chemistry at the site of calcification, rather than seawater Omega, are the main determinants of calcification. We found that changes in seawater pH and DIC rather than Omega had the greatest effects on calcification and calcifying fluid chemistry, though the effects of seawater carbonate chemistry were limited. Our results demonstrate the capacity of organisms from taxa with vastly different calcification mechanisms to regulate their internal chemistry under extreme chemical conditions. These findings provide an explanation for the resilience of some species to OA, while also demonstrating how changes in seawater DIC and pH under OA influence calcification of key coral reef taxa.
Keywords:
Acropora yongei; Alkalinity, total; Alkalinity, total, standard error; Animalia; Aragonite saturation state; Aragonite saturation state, standard error; Benthic animals; Benthos; Bicarbonate ion; Boron/Calcium ratio; Calcification/Dissolution; Calcification rate of calcium carbonate; Calcifying fluid, aragonite saturation state; Calcifying fluid, dissolved inorganic carbon; Calcifying fluid, pH; Calcite saturation state; Calcite saturation state, standard error; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. (2010); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard error; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Cnidaria; Coast and continental shelf; Containers and aquaria (20-1000 L or 〈 1 m**2); Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Full width at half maximum; Indian Ocean; Laboratory experiment; Macroalgae; OA-ICC; Ocean Acidification International Coordination Centre; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); Partial pressure of carbon dioxide (water) at sea surface temperature (wet air), standard error; pH; pH, standard error; Plantae; Pocillopora damicornis; Potentiometric; Potentiometric titration; Ratio; Registration number of species; Rhodophyta; Salinity; Single species; Species; Sporolithon durum; Temperate; Temperature, water; Temperature, water, standard error; Treatment; Type; Uniform resource locator/link to reference
Type:
Dataset
Format:
text/tab-separated-values, 3512 data points
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