Kaneohe Bay, Oahu

 

 Coral reefs are one of the many natural treasures that you can find in Hawai'i. They have been referred to as a "rainbow world" because of their colors, which camouflage, deceive, warn predators, or signal other organisms. Coral reefs are located in tropical oceans near the equator.

A coral reef is defined as "a strip of rock, sand or coral close to the surface of the ocean or any other body of water that is made up of millions of tiny animals called polyps. Around the world, you will hear a reef described as much more than a strip of coral.

Coral reefs are sometimes referred to as a "rain forest in the ocean" because, like tropical forests which have a large variety of life, coral reefs also have a large variety of life. In order to support all of this life, coral reefs are a complex system. Coral reefs in Hawaii play a very important role.

About 150 years ago, Charles Darwin, the father of evolution, divided the reefs into three types. He did this according to their relationship to a land mass. The three different types of reefs are fringing reefs, barrier reefs, and atolls. Most scientists today still use these classifications. Some scientists believe that there is a fourth type of reef, the patch reefs. Kaneohe Bay on the island of Oahu is an example of the fringing, patch and barrier reefs. Kaneohe Bay's barrier reef is often questioned if it really is a "true" barrier reef. It was not formed the same way as the Great Barrier Reef in Australia, but scientists say it sure looks and acts like a barrier reef.

Coral reef organisms can be found in different parts of the reef called zones. The zones are called the reef flat (0-2 meters in depth), reef bench (2-10 meters in depth), reef slope (10-30 meters in depth), and the rubble (30-40 meters in depth) zones. The coral community varies according to distance and depth from shore. Different environmental conditions can be found in the zones such as wave action, salinity, and temperature. Many reef organisms can survive only in a certain zone.