CORAL REEFS Almost every one of us have heard and most of you have seen the Coral reefs but did you know what actually these are: As a mariner its important to know about the marine life, that was one reason I have chosen this topic for my today's short presentation. GM, my scheme of presentation will be as flashed: DEFINITION OF CORAL REEF DIFFERENCE BETWEEN CORAL AND CORAL POLYP WHERE WE CAN FIND CORAL CONSTRUCTION OF CORAL REEFS CONDITIONS FOR GROWTH OF CORAL REEFS TYPES OF CORAL REEFS THREAT TO COAL REEFS WHAT SHOULD A MARINER DO IN CORAL RICH AREAS FUTURE OF CORAL REEFSCONCLUSIONWhat is a coral reef? Coral reefs are huge structures made of limestone that is deposited by living things. There are thousands of species that live in coral reefs, but only a fraction actually produces the limestone that builds the reef. Coral reefs support over 25% of all known marine species. They are one of the most complex ecosystems on the planet, and are home to over 4, 000 different types of fish, 700 species of coral and thousands of other plants and animals.
A good way to imagine a coral reef is to think of it as a bustling city or community, with the buildings made of coral, and thousands of inhabitants coming and going, carrying out their business. In this sense, a coral reef is like a metropolis under the sea. What is coral? Although coral is often mistaken for a rock or a plant, it is actually composed of tiny, fragile animals called coral polyps. When we say 'coral' we are actually referring to these animals and the skeletons they leave behind after they die.
Although there are hundreds of different species of corals, they are generally classified as 'hard coral' or 'soft coral'. Hard corals grow in colonies and are the architects of coral reefs. They include such species as brain coral and elk horn coral. Their skeletons are made out of calcium carbonate (also known as limestone) which is hard and eventually becomes rock. Hard corals are or reef-building corals and need tiny algae called (pronounced zo-z an-THE-ee) to survive. Generally, when we talk about 'coral' we are referring to hard corals.
Soft corals such as sea fingers and sea whips, are soft and bendable and often resemble plants or trees. These corals do not have stony skeletons, but instead grow wood-like cores for support and fleshy rinds for protection. They are referred to as or non-reef building corals and they do not always have. Soft corals are found in both tropical seas and in cool, dark regions. What is a coral polyp? A coral polyp is a spineless animal. Coral polyps can be the size of a pinhead while others are larger, sometimes a foot in diameter.
One coral branch or mound is covered by thousands of these animals. They are invertebrates (spineless animals) and are cousins of anemones and jellyfish. When thousands of these animals are grouped together, they are referred to as coral colonies. Each coral 'tree' or 'mound' is one colony of coral polyps. A polyp has a sac-like body and an opening or mouth encircled by stinging tentacles called.
The polyp uses calcium carbonate from seawater to build itself a hard, cup-shaped skeleton. This limestone skeleton protects the soft, delicate body of the polyp. Coral polyps are usually nocturnal, meaning that they stay inside their skeletons during the day. At night, polyps extend their tentacles out to feed. Where do corals live? Coral reefs are found in over 100 countries.
Most reefs are located between the tropics of Cancer and Capricorn, in places such as the Pacific Ocean, the Indian Ocean, the Caribbean, the Red Sea and the Arabian Gulf. Corals are also found farther from the equator in places where warm currents flow out of the tropics, such as Florida and southern Japan. Worldwide, coral reefs cover an estimated 284, 300 square kilometers (110, 000 square miles). How old are coral reefs? The geological record indicates that the ancestors of modern coral reef ecosystems were formed at least 350 million years ago. The coral reefs existing today began growing as early as 50 million years ago.
Most established coral reefs are between 5, 000 and 10, 000 years old. Although size sometimes indicates the age of a coral reef, this is not always true. Different species of coral grow at different rates, depending on water temperature, oxygen level, amount of turbulence, and availability of food How is a coral reef constructed? Coral reefs are complex, multi-story structures with holes and crevices shared by various creatures. If a coral reef can be thought of as a metropolis of the sea, then a coral colony can be thought of as an apartment building with many different rooms and hallways that house different marine species. Not all coral species build reefs.
The actual architects of coral reefs are hard or stony corals, which are referred to as or reef-building corals. As the polyps of stony corals grow, they produce limestone for their skeletons. When they die, their skeletons are left behind and are used as foundations for new polyps, which build new skeletons over the old ones. An actual coral mound or tree is composed of layer upon layer of skeletons covered by a thin layer of living polyps. The best place for coral to grow is in waters with the temperature being between 21 and 29 degrees. They do grow in hotter and colder places, but the growth rate there are very slow.
Corals like shallow waters, where there is lots of sunlight filters through to their algae. Its possible to find corals at depths of up to 91 metre's, but reef-building corals doesn't grow very well below 18 - 27 metre's. Corals don't grow very well near river openings or costal areas with too much, because corals need salt water to survive. What do corals need to survive? Sunlight: Corals need to grow in shallow water where sunlight can reach them. Since corals depend on the (algae) that grow inside of them and this algae needs sunlight to survive, corals too need sunlight to survive.
Therefore, corals rarely develop deeper than 50 meters (165 feet). Clear Water: Corals need clear water to survive and don't thrive well when the water is opaque. Sediment and plankton can cloud the water which decreases the amount of sunlight that reaches the. Temperature: Reef building corals require warm water conditions to survive. Different corals living in different regions can withstand different temperature fluctuations.
However, corals generally live in water temperatures ranging from 20 to 32 degrees Celsius (68 to 90 degrees Fahrenheit). Clean Water: Corals are sensitive to pollution and sediments. Sediments can settle on coral, blocking out sunlight and smothering coral polyps. Pollution from sewage and fertilizers increases nutrient levels in the water, harming corals. When there are too many nutrients in the water, the ecological balance of the coral community is altered. Saltwater: Corals need saltwater to survive and require a certain balance in the ratio of salt to water.
This is why corals don't live in areas where rivers drain fresh water into the ocean. What are the different types of reefs? Scientists generally divide coral reefs into four classes: fringing reefs, barrier reefs, atolls and patch reefs. Fringing reefs grow near the coastline around islands and continents. They are separated from the shore by narrow, shallow lagoons. Fringing reefs are the most common type of reef that we see. Barrier reefs also parallel the coastline but are separated by deeper, wider lagoons.
At their shallowest point they can reach the wa ter's surface forming a 'barrier' to navigation. The Great Barrier Reef in Australia is the most famous example and is the largest barrier reef in the world. Atolls are rings of coral that create protected lagoons and are usually located in the middle of the sea. Atolls usually form when islands surrounded by fringing reefs sink into the sea or the sea level rises around them (these islands are often the tops of underwater volcanoes).
The fringing reefs continue to grow and eventually form circles with lagoons inside. Patch reefs are small, isolated reefs that grow up from the open bottom of the island platform or continental shelf. They usually occur between fringing reefs and barrier reefs. They vary greatly in size, and they rarely reach the surface of the water.
Threats to Coral Reefs Living coral reefs are the foundation of marine life, and this also means that they are essential for human life, but all over the world they are dead or dying because people are destroying them at a very fast rate. Already 10% have been lost, and there are predictions that 705 of all corals on the planet will be destroyed in 20 to 40 years unless people stop doing what they are doing now - i. e. , pollution, sewage, erosion, cyanide fishing, bad tourism. The Crown of Thorn Starfish (COTS) is known as a natural and important member of a coral reef. Adult starfish can reach diameters of 40 cm or more and have lots of arms, ranging from 7 to 23.
COTS are covered by numerous long sharp poisonous spines and should be handled with the lots of care if removed on reef sites of commercial or scientific importance are they have to. Human activity has destroyed more than 35 million acres of coral reefs. Despite their protection in national parks, coral reefs in the United States face many of the threats suffered by reef ecosystems worldwide. Touching, kicking, walking on, or collecting coral when snorkeling or diving; dropping anchor on reefs when boating; or fishing in reef areas cause serious damage to reef ecosystems and devastate coral. In Florida, Biscayne and Dry Tortugas National Parks are suffering from overdevelopment of nearby lands, water pollution, boating, recreational and commercial fishing, and more than 3 million tourists yearly. Since 1930, Florida's population has increased four-fold.
Mangrove trees and sea grasses that normally act as filters for coral reefs are being rapidly destroyed as development increases, leading to heightened soil erosion. Soil, fertilizers, and sewage being dumped into Florida waters smothers corals and prevents them from obtaining enough light and oxygen to survive. Other forms of pollution, such as petroleum products and chemicals dumped near coastal waters, eventually will find their way to coral reefs as well, poisoning coral polyps and other marine life. What makes the difference When diving or snorkeling near coral reefs, DO NOT touch, stand or walk on, kick, or collect coral. Make sure none of your equipment bumps into the coral.
Don't purchase items made from coral or other threatened marine life. Avoid coral jewelry or other marine souvenirs unless you are certain that they were farmed or produced in aquaculture operations. If you own a tropical aquarium, demand that your aquarium store purchase only fish that have been certified 'cyanide free.' In many areas of the world, tropical fish are collected from coral reefs by releasing cyanide poison into the water, which kills the reef and many other marine species and stuns valuable fish for easy collection. Don't purchase coral pieces or 'live rock' for your tank unless there is proof they were not removed from the wild. Be very careful to collect all trash from beaches when you visit. Sea turtles have evolved to eat anything in the oceans, even poisonous Portuguese Man-of-War, but when turtles and other marine life eat plastics and other garbage, they risk fatal blockage of their digestive tracts.
Trash also can cover coral reefs and block the sunlight they need to survive. Don't order turtle, shark fin, or other restaurant dishes made from threatened wildlife. If you operate a boat, navigate carefully to avoid contact with coral reefs, never drop anchor onto a reef, and never dump trash or sewage into the water. The Future >>>Coral reefs constitute one of the most threatened of marine habitats. Because of their slow growth and fairly long life expectancy, they can't easily regenerate themselves, and their difficulty is made harder by the fact that they are permanently lined to the sea floor. That's why increasing pollution and irregular attack by predators prove particularly devastating.
A coral colony, which, together with its related flora and fauna, may have developed over 300 or 400 years, can be wiped out in a matter of minutes. Since coral growth varies from five to 200 centimeters a year, it has been estimated that some older reefs may have taken from 10, 000 to 30, 000 years to reach their present size. Further hazards, such as pollutants, refuse, sewage, oil, or other toxic substances, released intentionally or through shipwreck, have made the problem worse. Even the methods used in attempting to fix these problems have sometimes made the damage worse. The concern for the safety of coral reefs is getting bigger, but this concern has resulted in worldwide help to develop codes of conduct for maritime vessels. It has also led to the management of research on the effects of man's activities on coral reefs and coastal environments, and to the creation of protected marine areas.
These areas, such as the artificial reef created by the EAGLE, can act as replenishment reservoirs for fisheries and are designed to include maximum ecosystem diversity. Solutions>>>There have been increasing efforts to start better management and conservation processes to protect the variety of these biologically rich areas. Management practices have historically focused on the coral reef proper and not considered associated communities, such as sea grasses, mangroves, and mudflats or defined watersheds (which transport complex mixtures in their waters), in a significant manner. This attempted to manage the reef in isolation, like an island. Current management efforts recognize the importance of including reefs as part of a larger system, where included coastal zone management tools and watershed concepts can be used in the development of full management and protection plans. When reefs are considered as part of a larger watershed, the of the complexity of environmental stresses can be understood.
Management plans can be developed to reduce impacts to mangroves, sea grasses and the reef ecosystem, based upon accurate data and a better understanding of the system. EPA is in the process of developing guidance for a watershed approach to coral ecosystem protection. CONCLUSION Corals provide shelter for nearly one quarter of all known marine species. The reefs are home to over 4000 species of fish, 700 species of coral, and thousands of other forms of plant and animal life. Living coral reefs are the foundation of marine life, and this also means that they are essential for human life, but all over the world they are dead or dying because people are destroying them at a very fast rate. Already 10% have been lost, and there are predictions that 705 of all corals on the planet will be destroyed in 20 to 40 years unless people stop doing what they are doing now - i.
e. , pollution, sewage, erosion, cyanide fishing, bad tourism. We need coral reefs, and not just to make the ocean look pretty and colourful, they are more than just that... eggs.