Higher thermal resistance of corals in the global marine biodiversity center

Predictions for the future of coral reef are largely based on thermal exposure and poorly account for geographic variation in biological sensitivity and resistance to thermal stress. Based on the ratio of thermal exposure and sensitivity, geographic variability of coral resistance was estimated during the 2016 global-bleaching event. Exposure was estimated as historical cumulative excess summer heat (CTA) and a multivariate index of SST, light, and water flow (CE). Site sensitivity was estimated for 226 sites using coordinated bleaching observations. Site resistance was evaluated by 128 possible models for the influences of geography, historical SST variation, coral cover, and number of coral genera. Most factors were statistically significant but the strongest factor was geography - Coral Triangle having higher resistance than non-Coral Triangle sites. Consequently, future predictions of thermal stress will need to account for strong geographic differences in acclimation/adaptation.