The threats to coral

Coral bleaching

The vibrantly-coloured reefs turn a ghostly white due to the coral polyp expelling a photosynthetic algae that lives symbiotically with it. Incidents of bleaching are increasing due to corals coming under stress from pollution and global warming. Corals can survive bleaching but are left vulnerable to other stresses.

Ocean acidification

As levels of carbon dioxide in the atmosphere continue to rise, the oceans become more acidic as the gas dissolves in the sea. The acidity interferes with the coral’s ability to build its calcium carbonate skeleton. These massive structures can actually dissolve when exposed to acidity.

Disease and predators

As corals become weakened by bleaching they become more vulnerable to diseases such as black band disease. Sometimes, waves of predators move in and feed |voraciously on the coral tissue.