Question

What is the meaning of coral reefs​

Answer 1

a coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral held together by calcium carbonate

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Answer 2

A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. ... Coral reefs flourish in ocean waters that provide few nutrients.