Coral reefs provide some of the most diverse and productive communities on Earth.

They are found in the warm, clear, shallow waters of tropical oceans worldwide.

They provide food and shelter to fish and other sea-life.

The coral is made by living organisms called polyps which grow a skeleton that is deposited when the organism dies and builds up the coral.

A coral colony may consist of thousands and thousands of polyps. They are typically carnivorous, feeding on other organisms in the sea. They reproduce both sexually and asexually.

Corals are suspension feeders. Some have tentacles that can be used to sting prey and then move it into the mouth. Others will trap prey using a sticky mucus on their tentacles and again move the prey into their mouth.

Most corals feed at night when their food, the zooplankton, become available for capture.

Unfortunately many coral organisms can only tolerate a narrow range of environmental conditions, so they are very sensitive to damage, particularly from human changes to their environment.

Coral reefs provide a wonderful habitat for a large variety of sea creatures which rely on the coral as a source of food and shelter.

A wide variety of fish also depend on corals for protection against predators.

For example the Chumbe Reef Sanctuary, one of the world's most beautiful coral gardens which the rough scientists set out to protect has more than 200 species of coral and 370 species of fish.

Sponges (Porifera) are found inhabiting cavities in the reef. Crustaceans such as shrimps and crabs depend on corals for shelter.

This crown-of-thorns starfish relies on corals for food and has become a threat to the coral since it destroys the coral in the process.

There are many other species of fungi, sponges, sea worms, crustaceans and molluscs that bore into coral skeletons.

Other organisms that inhabit the coral reefs include sea urchins, jellyfish, oysters, clams, turtles, and sea anemones. A truly rich and varied environment.

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