Asds Weq Qwea Qwesad

Definition:
Coral reefs are underwater structures made from calcium carbonate secreted by corals. Corals are colonies of tiny living animals found in marine waters containing few nutrients. Most coral reefs are built from stony corals, and are formed by polyps that live together in groups. The polyps secrete a hard carbonate exoskeleton which provides support and protection for the body of each polyp. Reefs grow best in warm, shallow, clear, sunny and agitated waters.

Often called “rainforests of the sea”, coral reefs form some of the most diverse ecosystems on earth. They occupy less than 1% of the world ocean surface, about half the area of France, yet they provide a home for 25% of all marine species, including fishes, mollusks, echinoderms and sponges.

Coral reefs flourish even though they are surrounded by ocean waters that provide few nutrients. They are most commonly found at shallow depths in tropical waters, particularly in the Pacific Ocean, but deep water and cold water corals exist on a much smaller scale.

Distribution

Coral reefs are estimated to cover 280,000 square kilometers, which is just under one percent of the surface area occupied by the world oceans. The Indo-Pacific region (including the Red Sea, Indian Ocean, Southeast Asia and the Pacific) account for 92% of this total. Southeast Asia accounts for 32% of that figure, while the Pacific including Australia accounts for 40%. Atlantic and Caribbean coral reefs only account for 7%.

Principal coral reefs and reef areas of the world ▪ The Great Barrier Reef - largest coral reef system in the world, Queensland, Australia. ▪ The Belize Barrier Reef - second largest in the world, stretching from Mexico along the coast of Belize to the Bay Islands of Honduras. ▪ The New Caledonia Barrier Reef - second longest double barrier reef in the world, with a length of about 1,500 kilometers. ▪ The Andros, Bahamas Barrier Reef - third largest in the world, following the east coast of Bahamas, between Andros and Nassau. ▪ The Red Sea Coral Reef - located off the coast of Israel, Egypt, Sudan, Jordan and Saudi Arabia ▪ Pulley Ridge - deepest photosynthetic coral reef, Florida. ▪ Numerous reefs scattered over the Maldives. ▪ Ghe Raja Ampat Islands in Indonesia 's West Papua province offer the highest known marine diversity.

Importance of coral reefs
Coral reefs provide protection and shelter for many different species of fish. Without coral reefs, these fish are left homeless and no where to have their babies.Not only do these fish increase the diversity of our world, but also reef fish and mollusks feed between 30 and 40 million people every year. They also make beautiful pets and the money made by catching and selling these animals provides many people with an income so that they can feed their families.
And coral are very important in controlling how much carbon dioxide is in the ocean water. The coral polyp turns carbon dioxide in the water into a limestone shell. Without coral, the amount of carbon dioxide in the water would rise dramatically and that would affect all living things on Earth. Coral reefs are very important because they protect coasts from strong currents and waves by slowing down the water before it gets to the shore. That is why they are called barrier reefs. They provide a barrier between the ocean and the shore.
Threats:
Human Contact-Touching Reefs, even slightly, can harm them. Boats and dropped anchors can cause severe damage to these fragile ecosystems. Frequent human contact kills the reefs over time.
Runoff Water- Silt from eroded soil in runoff water can block sunlight. Without sunlight, photosynthesis does not occur and reefs gradually die.
Sewage- Untreated or improperly treated sewage promotes the growth of algae, which harms coral reefs.
Cyanide Fishing- Some fishermen stun fish by squirting cyanide, a very toxic poison, into reef areas where fish seek refuge. The poison does not kill, but disorients the fish in the coral where they hide. The fisherman then rip apart the reefs with crowbars to capture the fish. In addition, cyanide kills coral polyps and the symbiotic algae and other small organisms necessary for healthy reefs.
Fertilizers & Pollution- Fertilizer runoff, pesticides and other chemicals can poison reefs.
Conservation:

The creation of marine reserves should be off limits to fishing. About six percent of the world 's land is in parks. But at sea, less than 0.5 percent is in any kind of protected area. At the same time we will have to develop alternative livelihoods for fishers and regulate the trade in live reef fish and other threatened marine animals (corals, clams, turtles etc.). The answer lies in economic diversification and in non-consumptive uses of our marine resources. We must reduce the use of fossil fuels to avoid drilling for oil in the ocean and also reduce the pollution emission level to avoid bleaching of the coral reefs.
Conclusion:
Coral reefs are not given much importance in this world which is growing at a very rapid rate. We must do our bit and not buy products that effect the life marine organisms. We must arrange for alternative means of livelihood for the fishermen that are completely dependant on coral reefs. It is our duty to make sure that the coral reefs do not perish.
Bibliography:
http://www.mbgnet.net/salt/coral/threats.htm http://oceanworld.tamu.edu/students/coral/coral4.htm http://en.wikipedia.org/wiki/Coral_reef

Bibliography: http://www.mbgnet.net/salt/coral/threats.htm http://oceanworld.tamu.edu/students/coral/coral4.htm http://en.wikipedia.org/wiki/Coral_reef