Climate Change - Corals and Coral Bleaching
Healthy coral can be very colourful.
![](https://upload.wikimedia.org/wikipedia/commons/2/2e/Coral_Outcrop_Flynn_Reef.jpg)
Some coral reefs have started to look rather different.
![](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_sqSj0FDdZBKF6ZXM3UaQhaYeBVIzNg3klXQ9BgIHDZpiuRrcM5DR0sX3H4TdDlnzs8PTZmkZ0cft5XsDrAY9SSXdok9eS05DSghUmuusWc8hLqBYApeKY5vttUZdDyi3w=s0-d)
This is called 'coral bleaching'.
To understand this, we need to start by looking at corals.
Corals are animals that make a framework around them that looks like rock.
Coral animals (polyps) have tiny plants - algae - living in their tissues.
The algae provide food to the corals, which they produce by photosynthesis.
Reef-building corals only live in a limited temperature range.
Like porridge, they should be 'not too hot and not too cold'.
![Survival Factors | BioNinja](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_tgGPc7Mw9BxPDs8wkh2Er-YHpTb9q6XkQVbt-kpx1L8484WPYRPMB4F_66KuSmyvFA0t2yw8_UtekC5TE1hNfVAHZAV7axdEUNnqUgbTTFHwifr-cCo3QyxOR9be-Qsg=s0-d)
Coral reefs are concentrated in a band around the equator, between 30°N and 30°S latitude.
Algae in corals need light
Corals grow in warm, clear, shallow waters that receive plenty of light.
Most corals grow in the warmest water they can stand (about 85° F or 29° C).
This means that slight increases in ocean temperature can harm corals.
![](https://upload.wikimedia.org/wikipedia/commons/2/2e/Coral_Outcrop_Flynn_Reef.jpg)
Some coral reefs have started to look rather different.
This is called 'coral bleaching'.
To understand this, we need to start by looking at corals.
Corals are animals that make a framework around them that looks like rock.
Coral animals (polyps) have tiny plants - algae - living in their tissues.
The algae provide food to the corals, which they produce by photosynthesis.
Reef-building corals only live in a limited temperature range.
Like porridge, they should be 'not too hot and not too cold'.
Coral reefs are concentrated in a band around the equator, between 30°N and 30°S latitude.
Algae in corals need light
Corals grow in warm, clear, shallow waters that receive plenty of light.
Most corals grow in the warmest water they can stand (about 85° F or 29° C).
This means that slight increases in ocean temperature can harm corals.