With an estimated 20 percent of the world’s coral reefs already destroyed, Montipora foliosa faces many of the threats affecting coral reefs globally (5) (6). Worldwide there is increasing pressure on coastal resources resulting from human population growth and development. There has been a significant increase in domestic and agricultural waste in the oceans, poor land-use practices that result in an increase in sediment running on to the reefs, and over-fishing, which can have ‘knock-on’ effects on the reef (5). However, the major threat to corals is global climate change, with the expected rise in ocean temperatures increasing the risk of coral ‘bleaching’, in which the stressed coral expels its zooxanthellae, often resulting in the death of the coral. Climate change may also lead to more frequent, severe storms, which can damage reefs, and rising carbon dioxide levels may make the ocean increasingly acidic. Such stresses can also make corals more susceptible to disease, parasites and predators, such as the crown-of-thorns sea star (Acanthaster planci) (5) (6) (7).
Montipora foliosa is particularly vulnerable to predation by the crown-of-thorns sea star, as this voracious starfish has been observed to preferentially prey upon corals of the genus Montipora. Populations of the crown-of-thorns sea star have greatly increased over recent decades, and outbreaks of this species have caused mass mortality in Montipora foliosa, as well as degrading the overall quality of the reef environment. Montipora foliosa may also be threatened in some areas by harvesting, with Indonesia being the biggest exporter of this species. It is, however, perhaps more resilient to global warming and reef disturbance than some other coral species, due to its fairly large range of depth tolerances (1).