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What do coral reefs look like?

Inch by inch corals build reefs along the fringes of the volcanic islands and atolls in the clear, relatively shallow waters surrounding the Pacific islands. Though they may have similar organisms, no two coral reefs look the same. Each is influenced by waves, currents, water quality, and light. These factors shape how the reefs form and what types of animals live there. They also influence how a reef will respond to climate change. In order to understand the features of a coral reef and how it might respond to climate change, scientists at the National Park Service monitor coral reefs through the Inventory and Monitoring Program.

Explore how coral reefs vary by investigating national parks in the islands of American Samoa, Guam, and Hawaii.

Coral reef in American SamoaCoral reef in Guam

Coral reef in KAHOcoral reef of Kalaupapa