Coral reefs consist of limestone structures that give shelter to about 25 percent of all marine life in the Ocean. Considered one of the largest, most complex ecosystems on the planet, coral reefs are home to 4,000 species of fish, 700 species of coral, and countless amounts of other organisms (The Coral Reef Alliance, 2000). In the oceans, four types of coral reefs exist: the fringing reef, the barrier reef, patch reefs and atolls (Pinet, 2000). Charles Darwin first recorded 3 types of coral reefs on his studies of the Pacific Ocean, since then his theory has been widely accepted. Fringing reefs are the most common type of reef and develop near the coasts of landmasses. Barrier Reefs are similar to fringing reefs. These reefs run parallel to the coastline, yet deeper water separates them from the shore. The final type of reef is the atoll. Atolls develop in a ringed shape and create protected lagoons in the middle of the ocean (Pinet, 2000). Surprisingly coral reefs have limits on where they can grow. Most coral reefs develop in tropical waters between the Tropic of Cancer and Tropic of Capricorn. They can be found off the coast of 100 different countries worldwide and cover an estimated 600,000 square kilometers. With all of this information we can look at what causes their formation (The Coral Reef Alliance, 2000).
Coral reefs begin to develop in 3 main steps. First hard corals begin to grow by shedding their carbonate skeleton. After the hard coral dies it is usually attack by organisms that feed on the dead skeleton. The organism whether it be a parrotfish or a bivalve releases the remnants of the skeleton. The sediment produced by the organism then settles to the bottom of the sea floor or on top of other coral. This dead organic matter is then cemented to where it landed by minerals, and certain types of algae. This then adds to the growth of the reef structure even though the original hard coral may have died (Coral Reefs, 2000). Though this may seem like a simple process the growth of coral reefs may take hundreds of years to occur. Every different species of coral grows at its respective rate. The largest corals grow the slowest. Large corals grow anywhere from between 5 and 25 millimeters a year (Coral Reefs, 2000). Still smaller types of coral can grow about 20 centimeters a year. When looking at these numbers we find that the largest coral reefs we have today began to grow immediately after the last Ice Age, about 10,000 years ago. This staggering slow amount of growth shows that when we harm coral reefs today it will be hundreds of years before the damage is reclaimed. In all these statistics will be useful in showing how coral reefs are important to the Earth (Coral Reefs, 2000).
The diversity and the amount of organisms that live on a coral reef is incredible. It has been estimated that coral reefs provide a habitat for over 4,000 species of fish (Coral Reef Diversity, 2000). This figure calculates to about 18 percent of all fish in the world. On top of this, about 7,000 different species of coral make up the world's reefs (The Coral Reef Alliance, 2000). When you add in other types of plants and animals such as plankton, clams, or octopus you can conclude that the coral reef ecosystem is the most diverse ecosystem on the planet. The amount of organisms that call the coral reef there home is so large that there are too many to list. Included is picture's of some of these organisms.
Spotfin Butterfly Fish French Angelfish Barracuda Sea Anemone With all of these organisms, the importance of coral reefs is obvious. Why continue to destroy these organisms' habitat? At the same...