The Coral Reef

Reefs: ancient and valuable

Coral reefs have existed on the planet for approximately 450 million years.  Geological evidence, as represented in the fossil record, shows that ancient coral reefs were as complex an ecosystem as modern day reefs.

Present day reefs are considered one of the two most productive natural systems in the world, the other being the tropical rain forests.  Both these systems are currently at risk as a result of excessive and negligent use.  Coral reefs are increasing in economic value and must be protected.  Understanding and care will ensure their survival.

What is a coral reef?

Coral reefs are the largest natural structures in the world.  They are the result of a remarkable relationship between coral animals, known as polyps, and microscopic algae (zooxanthellae) living in their tissues.  The polyp, resembling a small sea anemone, is able to feed itself using stinging cells found on its tentacles which paralyze passing plankton.  The plankton is digested but supplies only a small part of the nutritional requirements of the polyp.  The remainder comes from the zooxanthellae which convert sunlight, carbon dioxide and their own wastes into oxygen and carbohydrates.  These carbohydrates are also used by the polyp to make calcium carbonate in a process known as calcification.  This material forms the skeleton of the coral and eventually the framework of what we recognize today as a coral reef.  137 species of coral are found on reefs in Southern Sinai. 

Coral reef ecosystems

Coral reefs provide food and shelter for thousands of organisms which co-exist in complex interconnected food chains.  Different behavioral patterns permit many organisms to share the same area, yet all organisms share common objectives: to occupy space and protect that space, to feed and to reproduce.  Organisms which are less successful in any of the above will, in time, disappear from the reef.

Coral reef ecosystems are in a constant state of change.  Corals grow and provide the framework for extension of the reef.  Simultaneously, the reefs are being broken down by animals living in or feeding on the structure (sponges, bivalves, urchins, fish).  If corals are damaged then the complex equilibrium of the reef will be permanently altered.  The result would be loss of productivity and biodiversity, both of which would have a serious economic consequences. 

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