Coral Reefs
Coral reefs are colourful underwater ecosystems built by tiny animals and home to a quarter of marine species.
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Play with the controls to see the idea in action.
📘 Learn
Coral reefs are colourful underwater ecosystems built by tiny animals and home to a quarter of marine species.
- Corals need warm, clear water
- Bleaching is caused by heat stress
- Reefs protect coasts
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is Coral Reefs?
Within Earth & Environmental Science, which covers our planet, its resources and ecosystems, and how people can protect the environment, this topic explains Coral Reefs. Earth and environment topics show how the planet’s systems shape landscapes, climate and life, with models that make these processes visible.
Check that you can explain Coral Reefs in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding Coral Reefs helps you explain the environment around you and weigh up how people can protect it.
Coral Reefs in detail
Coral reefs are underwater structures built by tiny animals called coral polyps, which secrete calcium carbonate skeletons. They live in warm, shallow, clear tropical seas, in a partnership with algae (zooxanthellae) that live in their tissues, giving them food and colour. The Great Barrier Reef is the largest.
Reefs cover less than 1% of the ocean floor but support about 25% of marine species, protect coasts from waves and support fishing and tourism. Threats include warming seas causing coral bleaching (when algae are expelled), ocean acidification, pollution, destructive fishing and physical damage. Protection involves reducing emissions, managing fisheries and local pollution, and restoration.
How the interactive helps you understand Coral Reefs
Watch the population model in the interactive. Use any sliders or buttons it offers to change the values and see how the population model responds.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Coral Reefs.
Real-life uses and examples
- Discuss how human activity changes Coral Reefs, using a named example.
- Explain how Coral Reefs affects the landscape or climate near you.
- Link Coral Reefs to a real environmental problem and a possible solution.
Common mistakes to avoid
- Presenting one cause as the only cause of an environmental change.
- Describing a process without the timescale it works over.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about Coral Reefs
What is Coral Reefs?
Coral reefs are colourful underwater ecosystems built by tiny animals and home to a quarter of marine species.
What are the most important points about Coral Reefs?
The main points are: Corals need warm, clear water; Bleaching is caused by heat stress; Reefs protect coasts.
Why is Coral Reefs useful?
Understanding Coral Reefs helps you explain the environment around you and weigh up how people can protect it.
How can I practise Coral Reefs?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to Coral Reefs?
Related topics in Earth & Environmental Science include Renewable Energy, Hydropower and Tidal Energy, Energy Conservation and Efficiency.