Stretching over 2000km along Australia's north-east tropical coast lies the largest structure ever to be built by marine organisms, the Great Barrier Reef. As the eighth wonder to the world, the Great Barrier Reef attracts over 2 million tourists every year, providing the economy with approximately $2 billion. However the price of popularity is evident as the reef suffers local, regional and global threats.
The ideal marine environment for coral is one, which has shallow, salty, moving water that is low in nutrients and has access to plenty of light. Coral is extremely sensitive to any changes in its marine environment and is not immune to the constant pressures it encounters. In 1981, this sensitivity called for the Reef to be added to the World Heritage Area's list which ensures the protection of this natural phenomenon. Therefore, as a result of the natural and human-induced factors, the ideal environment for coral has been compromised and protection of the reef ecosystem is essential if the Great Barrier Reef is to survive. .
In accordance with human-induced pressures, natural factors such as predators, cyclones and disease can also place immense stress on the fragile Great Barrier Reef. Predators such as the crown-of-thorns starfish often have outbreaks and destroy up to 95% of living coral, devastating large areas of various reefs. Since 1985, almost $5 million has been invested into researching the "cyclic nature" of the starfish outbreaks but over a 25 year period, nothing has been uncovered (Lawrence et al, 2002:122). The only control methods developed thus far includes targeting individual starfish by collection or injection with sodium bisulphate (dry acid) which is a chemical solution that rapidly breaks down into non-toxic components. However, such a method would require repeated treatments and prove to be resource-intensive, costly and only suitable for small areas. The government is supporting research programs to determine any possible biological or other control mechanisms that will deplete the crown-of-thorns starfish during severe outbreaks, whilst not bringing about harmful repercussions.