A US government agency has found that there may be good news for coral reefs this year.
The National Oceanic and Atmospheric Administration have issued a climate forecast indicating that cooler water temperatures this year will mean that there are unlikely to be any major coral bleaching incidents this year. This is welcome news after 2010 was judged to be one of the worst years for coral bleaching since 1998.
Following the issue of this week’s Coral Reef Watch Satellite monitoring results, Dr Mark Eakin the coordinator of the NOAA Coral Reef Watch Programme said: "There is a little bit of stress, is not too bad and the forecast for this year doesn’t look bad at all.”
NOAA's Coral Reef Watch Program's satellite data provides twice-weekly alerts on current reef environmental conditions to quickly identify areas at risk for coral bleaching through both remote sensing and in-situ tools. Whilst watch warnings were put on a number of coral reefs, only small areas of coral off the coast of Mexico, Columbia, Western Africa and South West Australia were at significant risk of bleaching or mortality.
Coral bleaching is caused by a variety of factors, including excessive chemical nutrients, pesticides and other land-based pollutants washed into the sea by rivers.
However the major cause of global bleaching events is warmer ocean temperatures, a direct effect of the climate change. Higher sea temperatures affect the symbiotic algae on which the coral depends for its food resulting in the algae effectively poisoning the coral and turning it white. If a coral is severely bleached, disease and partial mortality become likely, and the entire colony may die.
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