As much as 80 % of coral reefs in parts of Western Australia ’s Peel Region were severely affected by global bleaching in 2016 . Dr Schoepft said bleaching had rapidly increased in frequency since 1980, caused by a hike in atmospheric carbon dioxide. Some in - shore Kimberley reefs suffered bleaching for the first time last year even though its corals are considered to be tougher than most . Bleaching occurs when a spike in ocean temperatures puts coral under stress , causing it to expel the tiny photosynthetic algae responsible for its colours and turning them completely white .
As much as 80 % of coral reefs in parts of Western Australia ’s Peel Region were severely affected by global bleaching in 2016 . Some in - shore Kimberley reefs suffered bleaching for the first time last year even though its corals are considered to be tougher than most . Bleaching occurs when a spike in ocean temperatures puts coral under stress , causing it to expel the tiny photosynthetic algae responsible for its colours and turning them completely white .