CORAL - Traveling the Ocean Exploring Nature's Beauty

Corals are highly sensitive to environmental changes. Scientists have predicted that over 50% of the world's coral reefs may be destroyed by the year 2030;[23] as a result most nations protect them through environmental laws. Algae can overwhelm a coral reef if too many nutrients are present. Coral will also die if the water temperature changes by more than a degree or two beyond its normal range or if the salinity of the water drops. In an early symptom of environmental stress, corals expel their zooxanthellae; without their symbiotic unicellular algae, coral tissues become colorless as they reveal the white of their calcium carbonate skeletons, an event known as coral bleaching.[24]

Many governments now prohibit removal of coral from reefs and use education to inform their populations about reef protection and ecology. However, many other human activities damage reefs, including mooring, fishing, diving, mining and construction.

The narrow niche that coral occupies, and the stony corals' reliance on calcium carbonate deposition, means they are susceptible to changes in water pH. The increase in atmospheric carbon dioxide has caused enough dissolution of carbon dioxide to lower the ocean's pH, in a process known as ocean acidification. Lowered pH reduces the ability of corals to produce calcium carbonate, and at the extreme, can entirely dissolve those skeletons. Without deep and immediate cuts in anthropogenic CO2 emissions, scientists fear that ocean acidification will result in the severe degradation or destruction of coral species and ecosystems.[25]