Journal Article climate change corals climate coral bleaching coral reefs refugia temperature thermal stress turbidity Amazonia Comment El Niño-Southern Oscillation Letter Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. Review bright spots climate change refugia conservation coral cover coral cover projections coral ecology cyclones erosion fire global warming hierarchical Bayesian model human disturbance irradiance