Introduction Coral, common name for members of a large class of marine invertebrates characterized by a protective calcium carbonate or horny skeleton. This protective skeleton is also called coral. Corals are divided into two subclasses, based on differences in their radial symmetry. One subclass consists of colonial, eight-tentacled animals, each with an internal skeleton. Among them are whip corals, gorgonian's, and the red coral used in making jewelry. Members of the other subclass commonly have six tentacles, or multiples of six, but other patterns are also observed.
They include the stony, or true, corals. Another class of the same phylum also contains forms known as coral that are not considered here. Coral reefs are arguably the world's most beautiful habitats. Coral reefs have been called the rainforest's of the oceans, because of the rich diversity of life they support. Scientists have not yet finished counting the thousands of different species of plants and animals that use or live in the coral reef. Materials and Methods (N/A) Results (N/A) Discussion There are three types of coral reefs: fringing reefs, barrier reefs, and atolls.
Fringing reefs are located close to shore, separated from land by only shallow water. Barrier reefs lie farther offshore, separated from land by lagoons more than ten meters deep. Atolls, on the other hand, are formed far offshore and they make a ring-shaped reef that close a circular lagoon. Coral reefs are the largest biological structures on the planet, with the largest being the Great Barrier Reef covering over 2000 kilometers along the east coast of Australia (Focus, 1995). The reef is said to be 500, 000 to 2, 500, 000 years old and is said to be visible from the moon.
(Scientific, 1987). There is only one large threat to this beautiful structure and that is the carelessness of man. Silt from deforested lands and pollution from crowded coastlines choke them, and overuse by coal miners, fisheries, and even tourists deplete and destroy coral reefs. There are many more factors, which add to the destruction of the coral reefs, which if not stopped it will destroy all coral reefs. Structure True corals secrete calcium carbonate from the bottom half of the stalk of the individual animal, or polyp, forming skeletal cups to which the polyps are anchored and into which they withdraw for protection. In the flattened oral disc at the top of the stalk is an opening, edged with feathery tentacles and cilia, that is both mouth and anus.
At night the tentacles extend from the cup, seize animal plankton that wash against them, and carry the food to the mouth. Stinging cells, or, on the tentacles can also paralyze prey. Scientific Classification Corals belong to the class Anthozoan in the phylum Cnidarian (or Coelenterate). Corals with eight tentacles make up the subclass Ostocorallia or Alcyonaria. Corals that commonly have six tentacles or multiples of six belong to the subclass Zoantharia (or Hexacorallia). Stony, or true, corals belong to the order Scleractinia (or Madreporaria).
Colonies Some exist as solitary polyps, but the majority are colonial. Colonial polyps average from 1 to 3 mm (0. 04 to 0. 12 in) in diameter.
They are connected laterally by tubes that are an extension of the polyps' gastrovascular cavities, and the colony grows by asexual budding from the base or the oral disc of the polyps. Living polyps build on the deposits of their predecessors; the wide range of branched or massive forms that result depends on the species involved. SybiosisCorals are animals not plants, but like plants sunlight is the key to their survival. They need it to power the millions of microscopic algae, called that live in their tissues. They co-exist in a mutualistic symbiotic relationship in which the algae provides the corals with food and oxygen in return for raw materials and a secure place to live.
This teamwork is what allows the reef to survive in nutrient-poor tropical seas. This relationship is sensitive to many changes in the environment such as cloudy waters or extreme temperatures. Any stress on the corals can cause them to expel their algae, a phenomenon known as bleaching (Futurists, 1993). With the algae gone, the coral skeleton is visible and eventually it dies. Some dead coral will eventually lead to eventual death of the whole reef. Threats to the Reefs There are four environmental factors that effect reef growth: temperature, salinity, water depth, and wave action.
These factors expose the reef to many changes in its environment, especially since it is located so close to shore. This also makes it hard for all of the species, which use the coral reef as a habitat to survive. Coral reefs are home to perhaps one-fourth of all marine species. This in turn effects the entire ecosystem of the ocean. Pollution by humans have directly or indirectly caused the death of 5%-10% of the world's living reefs, according to marine biologist Clive Wilkinson of the Australian Institute of Marine Science.
This estimate didn't take into account global warming and ozone depletion as a factor. Fisheries, oil spills, deforestation, tourists, and even reckless divers, who may drive their cars into the ocean, cause the pollution, which may eventually lead to reef death. The problems, which are becoming even larger issues are the problems of deforestation and tourism. In the watershed of Bac uit Bay in the Philippines, deforestation increased erosion into the bay by more that 200 times. (Futurists, 1995) One of the biggest threats to coral reefs are tourists. Last year alone over 1.
2 million tourists visited the Great Barrier Reef. (Star-Bulletin, 1995) The tourists are not only visitors to the reef, fisherman, devoted divers and scientists who want to see the enormous reef also visit frequently. Every year the numbers of visitors increase by 10%. It has brought many resorts to the area that also want to cash in one the one billion-dollar business.
Even the hotels and motels pollute the reefs with the run off from their drainage and sewage pipes. This is causing a huge problem in coastal tourism which is the world's fastest growing industry, worth over $7 billion annually in the Caribbean. (Star-Bulletin, 1995) Marine Scientist's are concerned about how much longer the reef can survive with all these visitors. Global warming and ozone depletion are also major contributors to destruction of the earth's coral reefs. Global warming is said to cause the effect of bleaching, as mentioned earlier. This bleaching has just started in the islands of Hawaii.
The temperature of the water in Hawaii is said to have risen over two degrees in just one decade which the scientists think soon will show the effects in their reefs (Star-Bulletin, 1995). Another example is the time during 1982-83 better known as the El Nino effect, during which unusually warm water flowed from South America's Pacific Coast, up to 70%-90% of the corals off the Pacific coasts of Costa Rica, Panama, and Columbia all died. Also, coral mortality was more than 95% off Ecuador's Galapagos Islands (Futurists, 1993). Scientists have found that temperatures more than four degrees Celsius above normal, even for a few hours, will result in greater that 90% coral mortality. Reef Resources The coral reefs can provide many raw resources to mankind if they are taken from the reefs with care and responsibility. Coral reefs yield approximately one-tenth of all fish caught for human consumption, or around 4 to 8 billion tons annually (Futurists, 1993).
Healthy reefs are thought to be among the most productive fisheries in the ocean, 10 to 100 times higher per unit area that of the deep ocean (Scientific, 1987). If the fisheries are regulated than the reefs can be used as a food source without harming the reefs or the ecosystem. For example, Pacific Islanders obtain up to 90% of their animal protein from reef fish without affecting the reefs and without depleting the fish and effecting the ecosystem (Star-Bulletin, 1995). Surprisingly, some of the world's largest oil and gas fields are ancient reefs. Like the rain forests, the reefs also hold considerable untapped potential in the science of medicine.
Japan's coast is one of the most studied coral coasts in the world. In Japan's reefs there is a chemical called kai nic acid, which is used as a diagnostic chemical to investigate Huntington's chorea, a rare but fatal disease of the nervous system (Focus, 1995). Coral also produces a natural sunscreen, which is now being marketed to sell as a sunscreen to humans in America. Also, the porous limestone skeletons of coral is now being tested as bone grafts in humans (Focus, 1995).
More promising testing is being done on other reef organisms to generate chemicals for cancer and AIDS research. If used properly, the reefs of the entire world can better serve humans with medicine rather than with food. How Long They Will Last There have been many studies on how long the coral reefs will last, and every one of the studies agree that within fifty years, coral reef existence will be cut in half. The studies also say that within one hundred years they could be completely destroyed.
What is Being Done This should be a wake up call to all humans that we as a society have to do something about saving our coral reefs. If these reefs are destroyed it is thought that it might destroy the entire ecosystem of the ocean. There are over sixty-five countries that have designated some 300 parks that include coral reefs as natural habitats in the world (Futurists, 1993). The problem is that less that 30% of the designated areas are fully protected.
The fight is economical not ecological. Such as Australia and the Caribbean who are making billions of dollars with tourism on their coral reefs. Conclusion Everyone must work together to stop the pollution and the destruction of our coral reefs and our environment. It is not just one thing that is destroying the reefs it is many factors together that are destroying it. Ultimately, it is as much a question of whether we save or destroy the planet as it is a question of whether we save or destroy the world's reef.
References Cited Aldridge, Susan (April, 1995) "Coral: Replacement for Human Bones" Focus. Gore au, Thomas (August, 1987) "Coral and Coral Parks" Scientific American. TenBruggencats, Jan (May, 1995) "Coral in Hot Waters" Star-Bulletin & Advertiser. Weber, Peter (July, 1993) "Saving the Coral Reefs" Futurists.
Lacy A. MorroneInvertebrate Zoology 11/16/01 Coral Reefs Abstract Coral reefs have been called the rainforest's of the oceans, because of the rich diversity of life they support. Scientists have not yet finished counting the thousands of different species of plants and animals that use or live in the coral reef. There are several different types of coral reefs and they are the largest biological structures on the planet.
There is only one large threat to this beautiful structure and that is the carelessness of man. Silt from deforested lands and pollution from crowded coastlines choke them, and overuse by coal miners, fisheries, and even tourists deplete and destroy coral reefs. Corals are animals not plants, but like plants sunlight is the key to their survival because of the algae they co-exist with in a mutualistic symbiotic relationship. There are four environmental factors that effect reef growth: temperature, salinity, water depth, and wave action. These also make it hard for all of the species, which use the coral reef as a habitat to survive. Coral reefs are home to perhaps one-fourth of all marine species.
This in turn effects the entire ecosystem of the ocean. Pollution by humans has directly or indirectly caused the death of 5%-10% of the world's living reefs. Global warming and ozone depletion are also major contributors to destruction of the earth's coral reefs. The coral reefs can provide many raw resources to mankind if they are taken from the reefs with care and responsibility. Coral reefs yield approximately one-tenth of all fish caught for human consumption, or around 4 to 8 billion tons annually. Like the rain forests, the reefs also hold considerable untapped potential in the science of medicine.
The threats to the reefs are so great that they could soon be wiped off the face of the earth unless preventative measures are taken very soon. If humans continue to treat the reefs, as we are now they as well as all they support and provide will be destroyed forever. Coral Reefs.