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Smithsonian National Museum of Natural History
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underwater scene

Enter through the world-famous rotunda in the National Museum of Natural History and explore the Sant Ocean Hall. You'll see fabulous and ferocious fossils, amazing preserved specimens and models, and the latest tools used to explore the ocean depths. But, wait - what's that over there? A quick flash of red, a wavy stripe of blue. It's the ocean hall's living model coral reef ecosystem-teeming with life!

Artistic rendering of the coral reef ecosystem
Preliminary artistic rendering of the Sant Ocean Hall's coral reef ecosystem.
Image courtesy: Smithsonian Institution, National Museum of Natural History

Enter the world of a tropical coral reef

The ocean hall displays a 1,500-gallon aquarium featuring a live reef modeled from an Indo-Pacific coral reef ecosystem. The organisms inhabiting the aquarium were grown in captivity or collected in a sustainable manner. The diversity of coral reefs in the wild has been threatened by the indiscriminate harvesting of organisms for the aquarium industry. Many new efforts are underway to tightly and sustainably regulate this trade. The model coral reef will introduce you to the rich diversity of life that exists in coral reefs.

Why is there so much life and so many different kinds of life on a coral reef?

Pacific reefscape
Pacific reefscape. Image courtesy: ©Chuck Savall
Coral reefs pulsate with colors and movement. Abundant sunlight and warm water provide food for thousands of species and the calcium carbonate reef structure itself provides a variety of homes. Life inhabits every surface, crevice, nook, and cranny. You'll learn how reef inhabitants hide, find food, reproduce, and move about. Corals provide many hiding places, and animals with keen vision play hide and seek.

Drawing on photographs, texts, specimens, live organisms, and the reef itself, the coral reef will introduce visitors to what corals are and how coral reefs are formed.

Are coral reefs important to us?

Yellowtail snapper
Yellowtail snapper with seafan. Image courtesy: NOAA, Florida Keys National Marine Sanctuary
They're beautiful, but so what? Coral reefs are important to the economy. They provide tourism, recreation, jobs, and storm protection. Did you know that they are sources of new medicines? Or that they provide early warning systems for environmental problems such as global climate change? Reefs are also wondrous places, worthy of protecting for their own sake.





Stressed Out!

Partially dead coral
Partially dead coral overgrown with algae Image courtesy: ©2005 Wolcott Henry

We have tremendous impacts on tropical coral reefs. They are in danger worldwide; many are sick or dying. Their health begins to decline from even slight changes in water temperature, salinity, and quality. Too much sediment from runoff can also be lethal because it blocks needed sunlight. Agricultural runoff, excess nutrients (often from pollution), toxic wastes and over-harvesting can all endanger coral reefs. Probably the greatest threats are rising water temperatures and ocean acidification linked to increasing carbon dioxide levels.

And the good news…

As the coral reef exhibit explains, public, private, and non-profit sectors are all working to preserve and restore reefs. Examples that are featured are protection efforts underway at the Northwestern Hawaiian Islands National Monument and the Florida Keys National Marine Sanctuary. There are things you can do, too.

To learn more, visit the following web sites:


  • The International Coral Reef Initiative
    The International Coral Reef Initiative (ICRI), established in 1994, is a partnership among governments, civil society and organizations seeking to stop and reverse the global degradation of coral reefs and related ecosystems. http://www.icriforum.org
  • NOAA's Coral Reef Information System (CoRIS)
    CoRIS offers a series of background essays on coral reefs, an illustrated glossary, professional exchanges showing coral scientists debating hot topics, and searchable reports and data related to coral reefs. http://coris.noaa.gov/
  • ReefVid
    Professor Peter J. Mumby, from the University of Exeter, has recorded video footage on coral reefs around the world. Over 500 video clips of corals, fish, bleaching, turtles, mangroves, etc., are available on this Web site, free for educational and research use. http://www.reefvid.org

Did you know?


  • Microscopic algae (zooxanthellae) inside corals give them their color. Stressed coral polyps expel the algae—a phenomenon called bleaching.
  • The Northwestern Hawaiian Islands contain some of the ocean's last remaining relatively undisturbed coal reef ecosystems, thanks to their isolation and legal protection since 1909.
  • Even people far from reefs have an impact on them. Runoff from lawns, sewage, urban development, and farms brings excess nutrients. These feed algae that overwhelm reefs.

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