Halo patterns around coral reefs may signal resilience / Worst coral bleaching episode on record hits 84% of the world's reefs / Global coral bleaching has now hit 84% of ocean's reefs in biggest-ever event / This popular coral island is banning tourists for 9 months / Suffocating seas: Low oxygen levels emerging as third major threat to tropical coral reefs / I explore the impact of wildfires on Hawaii's coral reefs / Coral reefs' surprising recovery linked to close neighbors / Nuclear power and coral reefs: World Bank explores expanding its remit / The life-and-death struggle of coral reefs / Broadcasting sounds of healthy coral reefs encourages coral larvae growth, study shows