Publication Date:
2024-03-15
Description:
Natural variability in pH in the diffusive boundary layer (DBL), the discrete layer of seawater between bulk seawater and the outer surface of organisms, could be an important factor determining the response of corals and coralline algae to ocean acidification (OA). Here, two corals with different morphologies and one coralline alga were maintained under two different regimes of flow velocities, pH, and light intensities in a 12 flumes experimental system for a period of 27 weeks. We used a combination of geochemical proxies, physiological and micro-probe measurements to assess how these treatments affected the conditions in the DBL and the response of organisms to OA. Overall, low flow velocity did not ameliorate the negative effect of low pH and therefore did not provide a refugia from OA. Flow velocity had species-specific effects with positive effects on calcification for two species. pH in the calcifying fluid (pHcf) was reduced by low flow in both corals at low light only. pHcf was significantly impacted by pH in the DBL for the two species capable of significantly modifying pH in the DBL. The dissolved inorganic carbon in the calcifying fluid (DICcf) was highest under low pH for the corals and low flow for the coralline, while the saturation state in the calcifying fluid and its proxy (FWHM) were generally not affected by the treatments. This study therefore demonstrates that the effects of OA will manifest most severely in a combination of lower light and lower flow habitats for sub-tropical coralline algae. These effects will also be greatest in lower flow habitats for some corals. Together with existing literature, these findings reinforce that the effects of OA are highly context dependent, and will differ greatly between habitats, and depending on species composition.
Keywords:
Acid-base regulation; Acropora yongei; Alkalinity, total; Alkalinity, total, standard deviation; Animalia; Aragonite saturation state; Aragonite saturation state, standard deviation; Benthic animals; Benthos; Bicarbonate ion; Bicarbonate ion, standard deviation; Biomass/Abundance/Elemental composition; Boron/Calcium ratio; Calcification/Dissolution; Calcification rate of calcium carbonate; Calcifying fluid, aragonite saturation state; Calcifying fluid, carbonate ion; Calcifying fluid, dissolved inorganic carbon; Calcifying fluid, pH; Calcite saturation state; Calcite saturation state, standard deviation; Calculated using seacarb; Calculated using seacarb after Nisumaa et al. (2010); Calculated using seacarb after Orr et al. (2018); Carbon, inorganic, dissolved; Carbon, inorganic, dissolved, standard deviation; Carbonate ion; Carbonate ion, standard deviation; Carbonate system computation flag; Carbon dioxide; Carbon dioxide, standard deviation; Cnidaria; Coast and continental shelf; Containers and aquaria (20-1000 L or 〈 1 m**2); EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Fugacity of carbon dioxide in seawater, standard deviation; Full width at half maximum; Identification; Indian Ocean; Laboratory experiment; Light; Macroalgae; Magnesium-Calcite; Maximal differences in pH; Name; Net photosynthesis rate, oxygen; OA-ICC; Ocean Acidification International Coordination Centre; Other; Partial pressure of carbon dioxide, standard deviation; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; pH, standard deviation; Plantae; Plesiastrea versipora; Potentiometric; Potentiometric titration; Primary production/Photosynthesis; Raman microscopy; Registration number of species; Respiration; Respiration rate, oxygen; Rhodophyta; Salinity; Salmon_Bay; Single species; Species; Sporolithon durum; Temperate; Temperature, water; Temperature, water, standard deviation; Treatment; Type; Uniform resource locator/link to reference; δ11B
Type:
Dataset
Format:
text/tab-separated-values, 11028 data points
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