I was scanning through the internet when I found out where corals are found. I can tell you the URL of the website I found the facts in the 'credits' part .
Coral reefs are found in about 100 countries. Coral reefs are the world’s most fragile, delicate but most endangered ecosystems. When the corals are stressed by high temperature, they lose their symbiotic algal cells and appear white. Depending on the intensity and duration of the stress, the corals may recover or die. If the present rate of destruction continues, 70% of the world's coral reefs will be destroyed within the next few decades.