coral reef

American  

noun

1. a reef composed mainly of coral and other organic matter of which parts have solidified into limestone.

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coral reef British  

noun

1. a marine ridge or reef consisting of coral and other organic material consolidated into limestone

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coral reef Scientific  

1. A mound or ridge of living coral, coral skeletons, and calcium carbonate deposits from other organisms such as calcareous algae, mollusks, and protozoans. Most coral reefs form in warm, shallow sea waters and rise to or near the surface, generally in the form of a barrier reef, fringing reef, or atoll. Coral reefs grow upward from the sea floor as the polyps of new corals cement themselves to the skeletons of those below and in turn provide support for algae and other organisms whose secretions serve to bind the skeletons together. The resulting structure provides a critical habitat for a wide variety of fish and marine invertebrates. Coral reefs also protect shores against erosion by causing large waves to break and lose some of their force before reaching land. The Great Barrier Reef off the northeastern coast of Australia extends for some 2,000 km (1,240 mi), making it the world's largest coral reef.

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coral reef Cultural  

1. A formation, at or near the surface of tropical waters, formed by skeletal deposits of corals, a form of sea life.

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Discover More

Atolls — ring-shaped islands that nearly or entirely enclose a lagoon — are coral reefs.

Coral reefs form a protective environment for a wide variety of marine animals.

Coral reefs are very sensitive to chemical pollution and changes in temperature and are considered to be in danger from environmental stress.

The largest coral reef is the Great Barrier Reef of Australia.

Etymology

Origin of coral reef

First recorded in 1735–45

Example Sentences

Coral reef conservationist and ecologist Dr Mark Erdmann told BBC News that he was "blown away, and so happy" about the government's decision to revoke the mining permits.

From BBC • Jun. 14, 2025

Coral reef bleaching across at least 53 countries, territories or local economies has been confirmed from February 2023 to now, scientists from the National Oceanic and Atmospheric Administration and International Coral Reef Initiative said.

From Seattle Times • Apr. 15, 2024

Coral reef ecosystems rely on microorganisms to recycle organic matter and nutrients.

From Science Daily • Apr. 5, 2024

Coral reef fish, too, are heading south to areas well outside their historic range.

From Salon • Nov. 28, 2022

Abercromby also gives a very graphic description of a Coral reef.

From The Beauties of Nature and the Wonders of the World We Live In by Lubbock, John, Sir

Related Words

• atoll
• beach
• shoal