Although widespread and common (1) (3), and believed to be relatively resilient to habitat loss and reef degradation (1), Platygyra daedalea faces a number of threats that are impacting coral reefs around the world, and so is assumed to be undergoing a population decline (1). An estimated 20 percent of the world’s coral reefs have already been destroyed (13), and a large percentage of those remaining are at risk of collapse as a result of human activities. These include overfishing, destructive fishing practices, coral mining, pollution, irresponsible tourism, and poor land management practices, which increase the amount of sediment, nutrients and pollutants entering the ocean (1) (10) (13).
In general, however, climate change may pose the greatest risk to corals, raising the risk of temperature extremes which can stress coral and cause it to lose its zooxanthellae. This process, known as ‘bleaching’, usually results in the death of the coral. Climate change may also lead to more severe, frequent storms, which can damage reefs, and rising carbon dioxide levels may lead to ocean acidification, which can reduce coral’s ability to create its hard skeleton (1) (10) (13). Such stresses may also make corals more susceptible to disease (1). In addition to these general threats, Platygyra daedalea is also the target of collection for the aquarium trade (1).