How Do Corals Build Reefs? | California Academy of Sciences

Let's look inside a polyp to see how it helps build a reef. It takes carbon from algae and seawater, turns it into calcium carbonate, and uses this chalky substance to build an internal skeleton.

This visualization showing the interior of the polyp during the skeleton-building process will change your understanding of how hard corals construct entire reefs!

View more free educational resources at https://www.calacademy.org/educators

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