Experimental design
Four treatments contrasted high and low temperature and pCO2:
Ambient temperature = 27.5 oC
Ambient pCO2 = 39.0 Pa
High temperature = 30.5 oC
High pCO2 = 86 Pa
Juvenile Seriatopora caliendrum were collected from Hobihu Reef, Nanwan Bay, Taiwan, and kept at the National Museum of Marine Biology and Aquarium (NMMBA), where they were placed randomly into the treatment tanks for incubations lasting 14 days. Corals were exposed to treatments in 8 tanks filled with filtered seawater. Treatments were maintained at a salinity of 33 and were monitored daily for temperature, salinity, irradiance, pH and carbonate chemistry.
Photochemical efficiency: The effects of temperature and pCO2 on photochemical efficiency were tested by measuring the maximum photochemical efficiency of open RCIIs (Type II reaction centers) in the dark (Fv/Fm) and the effective photochemical efficiency of RCII in the light (deltaF/Fm') using pulse amplitude modulation (PAM) fluorometry.
Photosynthesis-irradiance (P/I) curves: To test for the effects of pCO2 and temperature on the ability for Symbiodinium to utilize light and perform photosynthesis, net photosynthesis (P^net), determined from changes in O2 concentrations in seawater, was measured under different irradiances using three corals selected randomly from each treatment tank.
Chlorophyll-a concentration and Symbiodinium density: Chlorophyll-a concentration and Symbiodinium density were determined.
Relevant References:
For full details see Methodology, from C. B. Wall, T.-Y. Fan, P. J. Edmunds (2014) Ocean acidification has no effect on thermal bleaching in the coral. Coral Reefs 33:119-13