The Pacific Has About Twice as Many Coral Species as the Atlantic

Not all oceans are equally rich in coral. Generally, Pacific Ocean reefs hold about twice as many coral species as Atlantic Ocean reefs — the Pacific is the ocean basin with the most corals.

A coral reef. Pacific reefs generally have about twice as many coral species as Atlantic reefs. Credit: NOAA.

What limits where corals live

Reef-building corals are fussy about their water. Temperature and salinity (salt content) restrict where they can live, and the water must also be clear enough to let plenty of light through. Because of those limits, reefs are generally found only in tropical and semitropical waters.

Fewer species toward the poles

Coral diversity — the number of species — falls with distance from the equator, dropping toward about 30° north and south. Beyond those latitudes, reef corals are usually not found at all.

Sources

Based on "What ocean basin has the most corals?" from NOAA's National Ocean Service, a work of the United States government in the public domain.