California Academy of Sciences: Science @ Home - How Do Corals Build Reefs?

Take a tour of a tiny coral polyp to learn how they transform seawater and algae into the raw materials that make up a reef. 

(3 minutes)

While you watch this video, think about the four questions below. Share your answers with a friend or family member or just think in your head.

  • What do corals use to build their skeletons?
  • What do the corals do over and over again to build an entire reef?
  • How long might it take to build a reef?
  • How might the ocean impact the shape of the coral?

Listen to guiding questions



Science @ Home

Got some science-loving small frys at home? Keep them engaged with an all-new array of themed activity packs created for kids ages 4-11, packed with guided videos, hands-on crafts, and real experiments. New packs published every month!


Science Topics
Biology, Ecology, Zoology
Coral & Anemones
3rd Grade, 4th Grade, 5th Grade, 6th Grade

What are you looking for?


California Academy of Sciences

Website URL

Type of Resource


Assigned Categories