An update with recent photographs from the 2007 cold-water bleaching event at Heron Island (from Dr Selina Ward, a researcher and lecturer at the University of Queensland). At high tide, the bleaching (loss of the symbiotic algae) is clearly evident in the branching coral from the submerged reef flat (left); at low tide the exposure of massive corals (center) and branching corals (right) results in significant levels of mortality. See my post below (“Winter bleaching again on the southern Great Barrier Reef”) for further comment.