Life in a Coral Reef

Life in a Coral Reef

As morning sunbeams stream down through clear blue-green water, a coral reef, built of limestone from tiny sea animals. becomes a magical place. A coral reef overflows with underwater life. More sea creatures find food and shelter in coral reefs than in any other ocean habitat.

The Great Barrier Reef, a world of wonder off the coast of Australia, is more than 1, 200 miles long, the distance from Maine to Florida. The largest coral reef in the world, it began forming millions of years ago.

It's hard to believe that all coral reefs, large or small, are built by tiny sea animals called coral polyps, each the size of a grain of rice. In clear, shallow ocean water warmed by the sun, these tiny tube-shaped coral animals attach themselves to the skeletons of dead coral polyps, Layer upon layer of old coral polyps form beautiful coral reefs.

Other animals keep the reef sturdy. Sea cucumbers spit out the sand they cannot eat, which fills the cracks and crevices in the reef. This makes the reef stronger so wave action doesn't tumble and crumble it.

Two kinds of coral animals, hard coral polyps and soft coral polyps, live in colonies on the reef. Hard coral colonies look like boulders, pillars, cactuses, elk horns, or even brains. Soft coral colonies look like fans, fingers, flowers, bits of lovely lace, or multicolored swaying sea feathers. Hard corals are reef builders. Soft corals are reef decorators. Their rainbow colors give the reef its beauty.