Many corals live with tiny algae inside their tissues. The algae help provide food and colour. Stress can disrupt this partnership and leave the coral pale or white. This is bleaching. A bleached coral can still be alive, but continuing stress can make survival much harder.
Water and oceans · Discover & try
Can a bleached coral still be alive?
Reading level 1 of 5 · EarlyChange
Word help
Symbiosis
A close biological relationship between different organisms.
Bleaching
Loss of symbiotic algae or their pigments from coral tissue.
Mortality
Death, which is not identical to bleaching.
Watch · Try · Explain
See how it works
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Conceptual partnership and stress sequence; stage timing and recovery are not predictions for a real reef.
What to look for
- Distinguish algae loss from tissue death.
- Compare persistent stress with relief.
- Notice that progress is not a count of days.
Explain what you noticed
A different reef survey sees pale coral tissue but has not checked whether it is living. Which conclusion is justified?
Keep this idea: Bleaching is loss of symbiotic algae or their pigments; a bleached coral is vulnerable but not necessarily dead.
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Source material checked 2026-10-28. Explanations and activities by Nepedia. Source links do not imply endorsement.
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