Corals are subject to “bleaching” when the seawater temperature is too high: they lose the symbiotic algae that give coral its colour and part of its nutrients. Severe, prolonged or repeated bleaching can lead to the death of coral colonies. An increase of only 1°C to 2°C above the normal local seasonal maximum can induce bleaching. Many heat-stressed or bleached corals subsequently die from coral diseases.
As a result of changes in the heating of different parts of the ocean, patterns of variation in heat distribution across the ocean are also changing. Those changes in patterns result in significant changes in weather patterns on land Water masses are also moving differently in areas over continental shelves, with consequent effects on the distribution of species.