Climate and Pollution Could Be Causes of Crumbling Coral Reefs
THE headline was startling - ``Coral Bleaching Threatens Oceans, Life.''
This wasn't supermarket-tabloid sensationalism. It appeared recently in EOS, the official weekly of the American Geophysical Union. It was a warning from scientists to other scientists. That gave it punch.
The authors - Alan E. Strong and R.E. Montgomery at the United States Naval Academy in Annapolis, Md. - went on to explain:
``People around the world depend on the resources provided by the ocean to support life. But global-scale damage to the coral reefs, a large and integral part of the ocean environment that supports a variety of sea life, is a frightening prospect that may unfold in the coming years.''
This is only the latest of many expressions of concern for the world's coral reefs.
Over the past decade, coral has suffered extensive damage in many different places such as the Caribbean, the tropical Pacific Ocean, and even along Australia's Great Barrier Reef.
Normally colorful corals have turned white and died. Others have crumbled because they could no longer build strong skeletons. This is in addition to direct damage from careless fishing, tourism, or nearby commercial development.
As the Annapolis researchers note, scientists don't understand what is happening, although they have several suspects.
These include both climate variations and human pollution.
Coral is a joint enterprise between an animal and a plant - the microscopic algae zooxanthella. The coral animal gives the algae nitrogen, phosphorous, and a sturdy home. The algae feeds the animal with carbon compounds and provides the coral color.
It's easy to disrupt the relationship. A few degrees rise above normal water temperature can drive out the algae, thereby bleaching the coral and killing it. Montgomery and Strong have been studying this ``suspect.''