These facts about coral reefs will help kids understand one of the strangest living creatures on Earth. Coral reefs attract a large variety of ocean life. Fish, sea turtles, whales, and other sea life are attracted by coral reef or other sea life surrounding the reef. Find out some interesting facts about coral reefs.

• Coral is not rock, but it is hard material formed from tiny skeletons of invertebrate animals.


• The word coral is from the Greek work Korallion, from the original word for "pebble".


• Coral has many uses over history.  Coral was once thought to stop bleeding, guard against poison, and protect dogs from rabies.


• Coral is known for its natural beauty.  Coral has many colors, from reddish-pink, to white, to black.



A map showing where coral reefs are located. Photo Credit: noaa.gov



• Coral reefs flourish in shallow warm water, nearer the equator between the 30 degree north and south latitudes.


• Most coral lives in water that is less than 230 feet (70 meters) deep.


• Coral grows best in clear, salty, warm water.  The temperature range where coral grows best is between 73° and 85° F (23° and 29° C).


• Coral does not grow well near the outlet of a river or stream.  The water is typically less clear and contains less salt in these locations.


• There are known deeper water coral reefs.  Scientists believe these species of coral do not grow as quickly.


• There are over 800 different known species of hard coral.


• Coral grows because of co-dependence of two organisms.  First organism is the coral polyp, which looks a little like a plant with tentacles.  The second organism is a type of algae known as zooxanthellae.  The algae and the coral polyp provide nutrients and protection that they need to the other organism so they can both survive together.  This is called a symbiotic relationship.


• The coral polyps release calcium carbonate as a result of this relationship with the algae.  The calcium carbonate is the compound that makes the hard rock-like material.


• Scientists estimate that coral reefs only take up about 0.07 percent of the ocean floor.  This number may be slightly higher, however, since deep-water coral is not fully mapped.


• Even with its small size, scientists estimate that 25 percent of life in the ocean lives around a coral reef.



Coral attracts a large variety of life in the ocean.