Coral reefs are central to the biology of our planet, but in the past few decades, they have suffered a severe decline due to a variety of natural and anthropogenic disturbances. On a worldwide scale, the main disturbance is bleaching, which can be defined as the loss of endosymbiotic dinoflagellates and/or of their photosynthetic pigments from their cnidarian host; with that, the normal pigmentation of the tissue of cnidarians is generally lost and the white calcium carbonate skeleton becomes visible through the transparent tissue of the host. Coral bleaching can be triggered by multiple factors, but most of the bleaching observed in the field is a result of elevated sea surface temperature. It has been widely documented that bleaching is deleterious to coral reefs, significantly altering the biological and ecological processes that maintain reef communities; yet populations resistant to climate change have recently been identified, and it has been reported that acclimatization occurs in less than two years. The aim of this review is to provide up‐to‐date information regarding cnidarian‐dinoflagellate symbiosis; causes of coral bleaching; mechanisms underlying this phenomenon; consequences of bleaching; and the survival mechanisms by which coral reefs face this threat.
Part of the book: Corals in a Changing World