the great barrier reef

zooxanthellae 

Calcification

Conveniently

Exoskeleton

The great barrier reef has tropical corals and fish in it. Corals are animals. There are 400 species of coral in the great barrier reef. Coral make their own food by getting sunlight inside them and turning it into food (called zooxanthellae). When a coral dies it leaves its bones (exoskeleton) where it was, and a new coral grows on top of it. Coral reefs grow 1-3cm every year. 

The ocean near the equator is warm because it's closer to the sun. When carbon dioxide the coral dies because it's too warm and they can’t grow. When the coral dies, the fish will die or go away.