Why are coral reefs so important to us? They are places of beauty. They are also home to one quarter of the fish in the ocean. What would happen to them if the reefs died?
A coral reef is a little world all by itself. All the animals and plants depend on each other to live.
Coral are tiny animals called polyps. They make layers of calcium to help them hold onto the rocks. The calcium is the same mineral that makes the shell in hen eggs.
There are two kinds of coral. One is hard and the other is soft. Coral polyps have very soft bodies. Hard corals grow layers of calcium to protect themselves. Brain and stag horn corals are hard corals. They are stiff like rocks.
Soft corals do not grow that shell. They are sea fans, or sea whips. They move and sway with the water.
Coral need certain things to grow. They need warm, shallow, clean water. They need warmth and sun to live and grow. They also need clean water to breathe. If the water gets dirty, the dirt will settle on the coral. Coral animals cannot shake off the dirt or move to another place. Dirt would cut them off from food, light, and oxygen.
How have the waters stayed clean? They are cleaned by sea grasses and mangrove trees.
Mangrove trees have their roots in salt water. Their branches hold nests for water birds. Their roots trap nutrients and food for birds.
Mangrove roots also hold onto the ground. They keep it from washing away into the sea. When mangrove trees are cut, more dirt is lost. More mud can get out into the ocean.Paragraphs 10 to 19:
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