Many people are justifiably concerned with the potential impacts of climate change and ocean acidification on coral reefs. But, coral reefs have been declining for at least the last 25 years and probably much longer, overwhelmingly due to threats that are unrelated to climate change. If we do not address these impacts we will continue to lose coral cover and reefs will be more vulnerable to climate change and ocean acidification.
|A coral outcrop on the Great Barrier Reef (photo Wikipedia)|
|The Scott Reef system. The crescent shaped reef at the bottom is Scott Reef South, the small reef above the left arm of the crescent is Scott Reef and the pear shaped reef is Scott Reef North (photo Wikipedia).|
|The daisy parrotfish, Chlorurus sordidus, is an important herbivore on coral reefs (photo Dennis Polack, EOL).|
Ten years after the bleaching event the supply of coral larvae had returned to the levels seen before the bleaching. Two years later the amount of coral cover and community structure on the reef had largely been restored. The rate of recovery is made more remarkable by the occurrence of a second more moderate bleaching event, two cyclones and a disease outbreak.
The study highlights just how resilient coral reefs can be to the effects of climate change and other disturbances if chronic anthropogenic stress is low. Overfishing, sedimentation and pollution are causing severe declines in coral cover right now. If we can control these threats, coral reefs might be able to survive in a warmer, more acidic ocean.
Gilmour, J., Smith, L., Heyward, A., Baird, A., & Pratchett, M. (2013). Recovery of an Isolated Coral Reef System Following Severe Disturbance Science, 340 (6128), 69-71 DOI: 10.1126/science.1232310