Living coral (1/3)
The coral of Hanauma Bay is home to over 450 varieties of fish, as well as octopus, crabs and eels. This natural bay on the island of Oahu is full of a living coral forest that grows and feeds the resident animals. The coral formations and creatures that live there provide some of the most beautiful underwater landscapes on the planet. The coral reefs are evidence of the area’s natural beauty and bring thousands of visitors to Hanauma Bay every year.
What are living coral reefs?
Coral reefs are actually collections of living entities that reside under the seawater. They are made up of individual coral organisms. Coral is an invertebrate animal (a creature with no backbone) and belongs to the class Anthozoa. Coral reefs are referred to as “living” because they actually are. Many people mistake coral for rocks or other underwater objects.
Hanauma Bay is a perfect area to support a living coral reef. The area is in a tropical sea where there is mild wave action. The curved nature of the bay protects the coral reef from large waves that could rip it apart. The gentle waves create enough movement in the water to circulate food and oxygen, and the water is shallow enough to encourage coral growth.
Coral comes in two different varieties, but only one is present in Hanauma Bay. Hermatypes are hard corals that build reefs and are seen in Hanauma. They look like rocks and stones on the ocean floor. The other type, ahermatypes, resembles plants and anemones.
The floor of Hanauma Bay is covered by hard coral formations, which provide homes for fish and other creatures. Snorkelers visiting the bay glide along above the coral bed to see the marine life.
There are many different shapes and sizes of coral, but in Hawaii there are six dominant forms. Lobe, shelf, rice finger, cauliflower and blue corals are all represented in the Hawaiian waters. The relatively shallow waters of Hanauma Bay support lobe, rice blue and cauliflower corals.
All coral is made from “polyps” which are tiny animals. Polyps resemble up side down jellyfish and they secrete a skeleton to support themselves. What we see as coral is actually the skeletal remains of the polyps. Amazingly, the entire ecosystem of the coral reefs of Hanauma Bay is based on these tiny creatures.