Summary
Heat stress causes corals to expel their symbiotic algae, turning white and risking death.
In depth
Zooxanthellae are expelled when water is 1 to 2 °C above summer maxima for weeks. Corals can recover if stress subsides. Mass bleaching has occurred in 1998, 2010, 2016, 2017 and 2020s. Degree heating weeks measure stress.
Bleached corals starve if stress persists. Recovery takes a decade or more. Local stressors reduce resilience. Assisted evolution and shading are experimental.
Remember: bleaching is not death but a stress response.
Frequently asked questions
What is Coral Bleaching?
Heat stress causes corals to expel their symbiotic algae, turning white and risking death.
Which area of biology covers Coral Bleaching, and how advanced is it?
Coral Bleaching is one of the 54 topics in Marine & Environmental Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Coral Reefs, Marine Symbiosis, Recycling and Waste.
Can you give an example of Coral Bleaching?
Some corals associate with heat-tolerant symbionts.
What should I learn before Coral Bleaching?
Work through the Beginner topics in Marine & Environmental Biology first, such as Oceans, Ocean Zones, Plankton, then return to Coral Bleaching. Intermediate topics assume the Beginner vocabulary.
What topics are related to Coral Bleaching?
The closest topics to Coral Bleaching are Coral Reefs, Marine Symbiosis, Recycling and Waste, Ozone Depletion. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Coral Bleaching?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Coral Bleaching. To practise the whole of Marine & Environmental Biology, use the Marine & Environmental Biology quiz.
How is Coral Bleaching different from Coral Reefs?
Coral Bleaching: Heat stress causes corals to expel their symbiotic algae, turning white and risking death. Coral Reefs: Biodiverse ecosystems built by coral polyps living in partnership with symbiotic algae. Read both side by side and note what each one explains.
How should I study Coral Bleaching step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Coral Reefs and explain the difference aloud. Finally, take the Marine & Environmental Biology quiz and come back to this page for any question you miss.