2 At Home on the Reef

At Home on the Reef written by Julie Ellis

coral reef Coral reefs look like beautiful underwater gardens. They are made in warm seas by tiny animals called coral polyps. As old coral polyps die, new coral polyps grow on top of them. Coral reefs take thousands of years to grow. Some reefs grow close to land. Barrier reefs grow further out to sea. Coral atolls grow in a ring shape on top of old volcanoes. Coral reefs are found in clear, shallow water because hard corals need sunlight to grow.

lagoon All coral reefs are different, but most reefs have a low island, with a beautiful sandy beach. Close to the beach is a saltwater lake called a lagoon. Further out is the reef edge. Large coral grows on the edge of the reef. Different animals live in parts of the reef at different times. There are not many fish in the lagoon at low tide, but at high tide they move back in.

dolphin The largest coral reef in the world is the Great Barrier Reef in Australia. It is made up of about three thousand coral reefs and islands. Many plants, fish, and other animals live there. Dolphins and whales swim in the warm water. There is plenty of food for many different animals.

hard coral There are two types of coral, growing in many shapes and sizes. Hard corals are very strong. Some grow flat and others grow branches. soft coral Soft corals are easily damaged. Some are fan-shaped and some grow like branches on a tree. Others grow like bushes. They all have beautiful colours.

butterflyfish Divers can watch many colourful fish on coral reefs. Some fish, like sharks, live alone, and some live in schools. Butterflyfish move around in schools. They are friendly and will follow divers. Parrotfish use their special teeth to break off bits of coral to eat. clownfish Clownfish are easy to see because of their bright colours. Divers won't go too close to stonefish because they are very poisonous. When pufferfish feel frightened, they quickly puff up to double their size.