Researchers have recently concluded that the higher-than-usual water
temperatures off Australia's northeastern coast may cause a bout of coral bleaching that could affect as much as
60% of the reef. If this happens, it would be the worst rash of bleaching (did I just mix my metaphors?) since 2001-02,
which was the worst coral bleaching ever recorded on the Great Barrier Reef.
Bleaching occurs when the tiny plants (zooxanthellae) living in coral tissue – which provide corals with their color and food – call in sick due to high temperatures. Coral reefs do not (immediately) die when bleaching occurs. If the warmer water temperatures are only temporary, the zooxanthellae will rebound and again provide food for the corals. However, if the zooxanthellae continue to be inactive, then the coral’s food source is gone, which can lead to their death.
Interestingly, in November, Australian researchers concluded that some coral-dwelling algal cells help corals adapt to rising water temperatures by increasing their thermal tolerance. In other words, they’re like a blanket that keeps the coral cool.
[Thanks, Drew!]
