One of nature’s most beautiful sights and known as a living museum that holds thousands of years of marine history is the coral reef. But what exactly is a Coral Reef? Having been formed more than 50 million years ago the Coral Reef Ecosystem that being the proper term, is a home to millions of species, hidden beneath the ocean waters, the coral reefs runs free with life. Fish, corals, lobsters, clams, seahorses, sponges, and sea turtles are only a few of the thousands of sea creatures that rely on reefs for survival.
A coral reef is composed of many thin plates of calcium carbonate secreted over thousands of years by billions of tiny animals know as coral polyps. Each polyp excretes a calcareous-exo-skeleton and lives in a symbiotic relationship with host algae, zooxanthella, which gives the coral its amazing color that we have admired for years. Now the Zooxanthellae takes in the carbon dioxide, the process is through photosynthesis, then giving off oxygen as a somewhat by-product that is used by the host polyp. It has been known that millions upon millions of polyps grow on top of the limestone remains of former colonies to create the massive reefs, such as the Great Barrier Reef in Australia.
Corals are divided into two kinds and both are stationary on the ocean floor. Hard corals such as brain, star and pillar corals have rigid exoskeletons, or corallites, that protect their soft delicate bodies. Gorgonians, or soft corals, such as sea fans, sea whips, and sea rods, tend to sway with the oceans currents and lack an exoskeleton.
Now, some people think that these amazing marine gardens are all the same; they are actually divided into four different types, the Fringing reef, Barrier reef, Atolls, and the Patch reef.
Fringing reefs, one of the most common reefs, grow near the coastline around islands and continents and are separated from the shore by narrow, shallow lagoons.
Barrier reefs also parallel to the coastline, but are separated by deeper, wider lagoons. The Great Barrier Reef in Australia is the largest and most famous barrier reef in the world.
Atolls are rings of coral that create protected lagoons and are for the most part located in the middle of the sea. The Atolls form when islands surrounded by fringing reefs sink into the sea and/or the sea level rises around them.
Patch reefs are small, isolated reefs that grow up from the open bottom of an island platform or continental shelf, usually occurring between fringing and barrier reefs.
Reefs are extremely diverse marine ecosystems being host to over 4,000 species of fish, massive numbers of cnidarians, mollusks, crustaceans, and many other animals. But with combination of temperature changes, overuse of divers and pollution has led to the destruction of many coral reefs all around the world. Scientists have predicted that over 50% of the coral reefs in the world may be destroyed by the year 2030. During the 1997-1998 warming event, colonies near Panama were bleached and died within six years this species is now thought to be extinct. As a result coral reefs are generally protected through environmental laws.