By Amelia Keogh
Coral reefs are historic ocean animals. Read to find out about the most historic coral reefs.
The biggest coral reef
One reef is called the Great Barrier Reef. It is the largest reef in the world. The Great Barrier Reef is in Austrailia. It is over 1,250 miles. A coral reef grows about five inches a year.
One day in the 1980s a scientist was searching a coral reef. There was white stuff on it! Over time the scientist found out it was bleach. Some of the coral reefs have recovered. But not all.
More about It's bleached?
Some coral reefs have died after getting bleached.Coral reefs get bleached when it gets to hot for the coral reef.
So, coral reefs have problems but they are naturally beautiful.