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2 Coral Bleaching - A sign of the times

Photo Story Coral Bleaching Full



Coral Bleaching Time Series
Images from Craig Quirolo of Reef Relief
Compiled by the Marine Photobank.

The 500 year old coral head is part of an expansive reef off Key West, Florida, that has been monitored since 1993. In 1996, the coral head appeared healthy. By the following year, elevated water temperatures resulted in the bleaching and death of 80% of the head. Since then, much of the outlying coral reef colony has died and become overgrown with algae.

Coral bleaching - which is caused by environmental stress - is the loss of the microscopic pigmented algae (zooxanthellae) housed within a coral colony. While coral can often recover from bleaching once the stressing conditions subside, prolonged or extreme stress can kill not only individual corals but whole reef tracts.

Small or localized bleaching events can result from such stresses as pollution, sedimentation, disease, freshwater flooding, and especially elevated or decreased water temperature. However, a greater concern lies with episodes of bleaching over regional and global scales. Large-scale bleaching events have been linked to increases in sea surface temperature and have increased in incidence and severity over the last 25 years corresponding with global warming trends.

What can you do?
Learn more about how you can help with reef conservation by visiting www.reefrelief.org and www.coralreefalliance.org.

Also, do your part to reduce CO2 emmissions by cutting your fossil fuel use, conserve energy and support renewable energy sources such as wind and solar energy. Visit www.ucsusa.org for solutions or go to www.globalwarming.net to find out more.