Coral reefs are facing a range of serious threats worldwide, with an estimated 19 percent of reefs already lost (9), and around a third of all reef-building corals now threatened with extinction (10). The major threat to corals is global climate change, which is likely to lead to more frequent, severe storms, which can damage reefs, and to increase the risk of coral ‘bleaching’, in which high ocean temperatures cause the stressed coral to expel its zooxanthellae, often resulting in death. Rising carbon dioxide levels may also increase ocean acidity, reducing the ability of coral to create its hard skeleton (1) (6) (9) (10).
These global threats are compounded by direct human impacts, from coral harvesting, overfishing and destructive fishing methods, irresponsible tourism, invasive species, pollution and sedimentation. These combined stresses can also make corals more susceptible to disease, parasites, and predators, with the voracious crown of thorns starfish (Acanthaster planci) posing a particular threat (1) (6) (9) (10). Although Galaxea fascicularis is still common and widespread, so potentially making it more resilient to global threats, it is also targeted for the aquarium trade, with over 20,000 pieces exported in 2005 alone (1).