Academic Reading
The colours of coral
ACoral reefs are among the most colourful environments on Earth, yet the coral animals themselves are mostly transparent. Their striking colours come from tiny algae that live inside their tissues. In return for shelter, these algae use sunlight to make food, much of which they share with the coral.
BThis partnership is delicate. When the water becomes too warm, the coral expels its algae and turns a ghostly white, an event called bleaching. Without the algae, the coral loses its main food source, and if conditions do not improve, it can starve and die.