|Eddy Reef, Great Barrier Reef, Australia|
Mass coral bleaching is not new, but the increased frequency of occurrence leaves less time for recovery and more stress in the long-term. As it is a patchy event and affects various reefs differently, one focus of research is on the reason why and whether this can be used to help other reefs. Coral calcification is also declining and correlates with the rise of global temperatures. Unseen in over 400 years, coral calcification is what provides structural complexity to the reefs. Tens of thousands of species found within reefs depend on calcareous coral skeletons. Without intervention, some predict that by 2030 the Great Barrier Reef will be transformed to a non-coral dominate state.