Coral Reefs

Ross Coral

Taken by Kieran Boyce, Dublin University Sub-Aqua Club

Ross Coral
Taken by Kieran Boyce, Dublin University Sub-Aqua Club

Ross Coral

Taken by Kieran Boyce, Dublin University Sub-Aqua Club

Enlarge image

Coral reefs are beautiful habitats. They are formed from the skeletons of small sea animals called polyps. The first coral reefs of the world began forming about 500 million years ago!

There are two types of coral reefs.

1. Warm water coral reefs
2. Cold water coral reefs

Warm water reefs need sunlight to make food and grow. They are usually found in shallow waters. The sunlight makes the water warm. This is why they are named 'warm water reefs'. The Great Barrier Reef off Australia is a warm water shallow reef. It is about 500,000 years old.

Cold water reefs don’t need sunlight to make food. They are found much deeper in the ocean. As there is no sunlight, the water is cold. This is why they are named 'cold water reefs'. Cold water reefs take a very long time to grow. There are cold water reefs off the west coast of Ireland. Scientists think they are about 4,500 years old.

Octapus cartoon

More than 4,000 different types of fish live in coral reefs.

Great hunting sharks, sea snails, octopuses and sponges live around coral reefs. Sponges give shelter to small fish.

Do you know any other animals that live in coral reefs? There are more examples below.

Lobster cartoon

Lobster, crab and shrimp live in coral reefs. They have a very hard shell around their body. This helps to protect them from animals that are hunting for food.

However, they lose their hard shell as they get bigger. Then they must wait for a new, bigger shell to grow. This is a dangerous time for them. They hide from other animals under the corals and rocks. This makes coral reefs great habitats for them.

Lobsters and crabs have claws. These help them when swimming, crawling or eating.