Seawater carbonate chemistry and conceptacle abundance and size of coralline algae Hydrolithon reinboldii

• Main Authors: Moore, B, Comeau, Steeve, Bekaert, M, Cossais, A, Purdy, A, Larcombe, E, Puerzer, F, McCulloch, Malcolm T, Cornwall, Christopher Edward
• Format: Dataset
• Language: English
• Published: PANGAEA 2021
• Subjects: Alkalinity; total; Aragonite saturation state; 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; Diameter; Event label; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Generation; Growth/Morphology; Growth rate; Hydrolithon reinboldii; Identification; Indian Ocean; Laboratory experiment; Macroalgae; Number; OA-ICC; Ocean Acidification International Coordination Centre; Origin; Partial pressure of carbon dioxide (water) at sea surface temperature (wet air); pH; Plantae; Recruit size; Registration number of species; Reproduction; Rhodophyta; Salinity; Shell_Island; Single species; Species; Tallon_Island; Temperature; water; Treatment; Tropical; Type; Uniform resource locator/link to reference; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.932839; https://doi.org/10.1594/PANGAEA.932839

The future of coral reef ecosystems is under threat because vital reef-accreting species such as coralline algae are highly susceptible to ocean acidification. Although ocean acidification is known to reduce coralline algal growth rates, its direct effects on the development of coralline algal reproductive structures (conceptacles) is largely unknown. Furthermore, the long-term, multi-generational response of coralline algae to ocean acidification is extremely understudied. Here, we investigate how mean pH, pH variability and the pH regime experienced in their natural habitat affect coralline algal conceptacle abundance and size across six generations of exposure. We show that second-generation coralline algae exposed to ocean acidification treatments had conceptacle abundances 60% lower than those kept in present-day conditions, suggesting that conceptacle development is initially highly sensitive to ocean acidification. However, this negative effect of ocean acidification on conceptacle abundance disappears after three generations of exposure. Moreover, we show that this transgenerational acclimation of conceptacle development is not facilitated by a trade-off with reduced investment in growth, as higher conceptacle abundances are associated with crusts with faster growth rates. These results indicate that the potential reproductive output of coralline algae may be sustained under future ocean acidification.