Coral Bleaching

One of the greatest threats to the Great Barrier Reef is climate change, also known as global warming. Three times over the last ten years, the water in the seas surrounding the Great Barrier Reef has risen 1 or more degrees Celsius. While this may not seem that significant, any temperature increase threatens the coral reefs. When the water becomes warmer , coral become stressed. This stress causes them to force Zooxanthellae, an algae living in coral shells essential to the sustenance of the coral polyp, out of their shells. Without this algae, the coral is unable to use photosynthesis to form its color which is why the phenomenon is known as “coral bleaching”. Once the algae are absent, the coral’s white skeleton shows and the coral begins dying, stops reproducing and becomes vulnerable to disease. The Great Barrier Reef experienced episodes of coral bleaching in 1998, 2002 and 2006. Scientists estimate that the 2002 temperature increase caused 60 to 95% of the Reef’s coral to become bleached. Because water temperatures are likely to continue to rise, researchers predict that episodes of coral bleaching will continue to occur. Therefore, the Great Barrier Reef Marine Park Authority has formed a response plan aimed at detecting and responding to future occurrences.

http://www.globalissues.org/article/173/coral-reefs

What can you infer the result of coral bleaching is?