Seawater carbonate chemistry and physiological responses of coral recruits

• Main Authors: Jiang, Lei, Guo, Yajuan, Zhang, Fang, Zhang, Yuyang, McCook, Laurence John, Yuan, Xiangcheng, Lei, Xinming, Zhou, Guowei, Guo, Ming-Lan, Cai, Lin, Lian, Jian-Sheng, Qian, Pei Yuan, Huang, Hui
• Format: Dataset
• Language: English
• Published: PANGAEA 2019
• Subjects: Alkalinity; total; standard deviation; Animalia; Aragonite saturation state; Benthic animals; Benthos; Bicarbonate ion; Biomass per individual; Budding rate; Calcification/Dissolution; Calcification per individual; Calcite saturation state; Calcium adenosine triphosphatase activity; Calculated using CO2SYS; Calculated using seacarb after Nisumaa et al. (2010); Carbon; inorganic; dissolved; Carbonate ion; Carbonate system computation flag; Carbon dioxide; Catalase; unit per protein mass; Catalase activity; Cnidaria; Coast and continental shelf; Containers and aquaria (20-1000 L or < 1 m**2); Effective quantum yield; Excitation pressure; EXP; Experiment; Fugacity of carbon dioxide (water) at sea surface temperature (wet air); Growth/Morphology; Growth rate; Identification; Laboratory experiment; Lipid peroxidation; per protein; Luhuitou_reef; Magnesium adenosine triphosphatase activity; Ocean acidification
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.922140; https://doi.org/10.1594/PANGAEA.922140

Diurnal pCO2 fluctuations have the potential to modulate the biological impact of ocean acidification (OA) on reef calcifiers, yet little is known about the physiological and biochemical responses of scleractinian corals to fluctuating carbonate chemistry under OA. Here, we exposed newly settled Pocillopora damicornis for 7 days to ambient pCO2, steady and elevated pCO2 (stable OA) and diurnally fluctuating pCO2 under future OA scenario (fluctuating OA). We measured the photo-physiology, growth (lateral growth, budding and calcification), oxidative stress and activities of carbonic anhydrase (CA), Ca-ATPase and Mg-ATPase. Results showed that while OA enhanced the photochemical performance of in hospite symbionts, it also increased catalase activity and lipid peroxidation. Furthermore, both OA treatments altered the activities of host and symbiont CA, suggesting functional changes in the uptake of dissolved inorganic carbon (DIC) for photosynthesis and calcification. Most importantly, only the fluctuating OA treatment resulted in a slight drop in calcification with concurrent up-regulation of Ca-ATPase and Mg-ATPase, implying increased energy expenditure on calcification. Consequently, asexual budding rates decreased by 50% under fluctuating OA. These results suggest that diel pCO2 oscillations could modify the physiological responses and potentially alter the energy budget of coral recruits under future OA, and that fluctuating OA is more energetically expensive for the maintenance of coral recruits than stable OA.