The Reefs at Lady Musgrave have been fortunate and have not suffered badly from coral bleaching.  The reef at Lady Musgrave is in excellent condition and GBRMPA monitor the conditions regularly.

Coral bleaching is the loss of colour from corals.  This loss of colour is caused when the symbiotic algae (called zooxanthellae – very small single cell algae) leave the coral due to being under stressful conditions.  The corals live with this zooxanthellae in a mutually beneficial partnership where the zooxanthellae provide nutrients and the coral provides a home.  However when the conditions (like water temperature and light) become outside the preferred range of environmental conditions then the zooxanthellae and also the corals are damaged.  As a result large amounts of zooxanthellae leave the coral.  This means the colour is lost and looks pale.

In extreme cases the coral looks bleached white as all the zooxanthellae have left leaving the coral white and dead.  Dead coral looks white because, like our bones, it is mostly made of calcium carbonate.  This is why the coral rubble beach on Lady Musgrave Island is such a white beach.