About
Coral reefs are built by tiny coral polyps — each a small animal related to jellyfish — that secrete calcium carbonate skeletons and live in symbiosis with photosynthetic algae (zooxanthellae). Covering less than 0.1% of the ocean floor, coral reefs shelter approximately 25% of all marine species, protect coastlines from storm surges, and support the livelihoods of over 500 million people.
Coral bleaching — caused by warm water temperatures driving out the symbiotic algae — is devastating reefs worldwide. The Great Barrier Reef experienced five mass bleaching events between 1998 and 2022; scientists estimate 50% of its coral has been lost since 1995. At 1.5°C of global warming, 70–90% of coral reefs may die; at 2°C, 99% would be lost.
# Top 10 Coral Reefs facts
- 1Coral reefs cover less than 0.1% of the ocean but support 25% of all marine species
- 2The Great Barrier Reef is the world's largest living structure — visible from space
- 3At 2°C of global warming, 99% of the world's coral reefs could be lost — devastating marine biodiversity
Fascinating Facts
- ◆Coral reefs cover less than 0.1% of the ocean but support 25% of all marine species
- ◆The Great Barrier Reef is the world's largest living structure — visible from space
- ◆At 2°C of global warming, 99% of the world's coral reefs could be lost — devastating marine biodiversity
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