Web Results
Coral reefs are underwater structures formed from the calcium carbonate secreted by corals.

Coral reef - Wikipedia

en.wikipedia.org/wiki/Coral_reef

Coral reefs are diverse underwater ecosystems held together by calcium carbonate structures secreted by corals. Coral reefs are built by colonies of tiny animals ...

Coral Reef | Basic Facts About Coral Reefs | Defenders of Wildlife

www.defenders.org/coral-reef/basic-facts

Coral reefs are some of the most diverse ecosystems in the world, housing tens of thousands of marine species. About one-third of all marine fish species live ...

Corals and Coral Reefs | Smithsonian Ocean Portal

ocean.si.edu/corals-and-coral-reefs

Coral reefs are the most diverse of all marine ecosystems. They teem with life, with perhaps one quarter of all ocean species depending on reefs for food and ...

What Are Coral Reefs? | Coral Facts - Live Science

www.livescience.com/40276-coral-reefs.html

Oct 8, 2013 ... Coral reefs are large underwater structures composed of the skeletons of coral, which are marine invertebrate animals.

NOAA CoRIS - What are Coral Reefs

www.coris.noaa.gov/about/what_are/

Dec 16, 2014 ... Coral reefs are unique (e.g., the largest structures on earth of biological ... Corals are anthozoans, the largest class of organisms within the ...

What is a coral reef made of? - NOAA's National Ocean Service

oceanservice.noaa.gov/facts/coralmadeof.html

A coral reef is made of thin layers of calcium carbonate.

Coral Reefs

life.bio.sunysb.edu/marinebio/coralreef.html

Coral reefs are the most diverse and beautiful of all marine habitats. Large wave resistant structures have accumulated from the slow growth of corals.

Corals, Coral Pictures, Coral Facts - National Geographic

animals.nationalgeographic.com/animals/invertebrates/coral/

Coral reefs teem with life, covering less than one percent of the ocean floor, but supporting about 25 percent of all marine creatures. However, threats to their ...

What are corals? | International Coral Reef Initiative

www.icriforum.org/about-coral-reefs/what-are-corals

Corals are invertebrate animals belonging to a large group of colourful and fascinating animals called Cnidaria. Other animals in this group that you may have ...