Reef Report for Thursday, April 1, 2004
Coral Bleaching Threat Over For This Year
The Great Barrier Reef Marine Park Authority (GBRMPA) announced that the threat of coral bleaching has passed for this year with little or no bleaching noticed along the reef.
GBRMPA, the government agency responsible for protection and monitoring of the Great Barrier Reef, closely follows ocean temperatures during the summer months of February through April, when water temperatures are warmest.
Coral lives in tropical waters, and they are quite sensitive to high ocean water temperatures, as well as elevated ocean salinity and high light intensity.
When the combination of these factors causes too much stress on a coral colony, the corals eject the brown-colored algae (zooxanthellae) that live inside them, and lose color, hence the term coral bleaching.
Corals can recover from bleaching events, depending on the intensity and duration of the stressful conditions. Certain species of coral are also more resistant to bleaching or able to recover from bleaching events.
Global warming is thought to be a key culprit in the elevated summer ocean temperatures witnessed in tropical oceans worldwide over the past decade. Current climate models vary on where the trend will go but this year’s experience parallels the predictions of some climate models, which predict some coral reef regions will be protected somewhat by an increased frequency of tropical storms, which cool ocean waters by obscuring the sun, rainfall, and especially strong winds that mix warm surface waters with cooler deeper waters. In the northern reef region a timely tropical storm in March brought the clouds, rains, and winds, cooling ocean temperatures to well below the level that is stressful to corals.
We urge you to help protect coral reefs worldwide by reducing your contribution to the gasses that cause global warming, to educate yourself, and to consider joining organizations that work to reduce the problem.
About Coral Bleaching
GBRMPA Coral Bleaching Threat Report, 2004
National Resources Defense Council
The weekly reef report is written by Joel Groberg of DiveTheReef.com,
who compiles them from the many conversations he has with dive staff in the area, as well as many other local sources in the dive
Index of all reef reports.