Coral-algal physiology
Corals showed a significantly lower photochemical efficiency (Fv/Fm) after exposure to the heat treatment (Supplemental Fig. 1.A, t = 4.37, df = 5.94, p-value < 0.005). GP:R ratios also decreased, although the mean difference was not statistically significant (Supplemental Fig. 1.B, t = 2.31, df = 3.39, p = 0.09). There were no visual signs of paling or bleaching of coral nubbins during the experiment.