Science Common Sense

399 - What is coral bleaching, and why does it happen?

Coral bleaching is when coral turns white and often dies. It happens when the coral gets stressed, usually because the water is too hot or too dirty.

Coral is actually a living animal that has tiny plants called algae living inside it. The algae help the coral make food from sunlight, and the coral provides a home for the algae.

When the water gets too hot, the algae can't survive, and they leave the coral. Without the algae, the coral turns white and can't make food. If it doesn't get the algae back, the coral can die.

Pollution and climate change can also cause coral bleaching. It's like when you're sick and need to rest, coral gets stressed and needs our help to recover.