Coral Reefs, The City Under the Ocean By Nick Gray Mr. Mullen English 1102 27, February 1999 Coral Reefs: The City Under the Ocean. It was a hot sunny day off the Bahamas shoreline when my family and I went snorkeling for the first time. We took a boat out to the coral reef and dove down to find an underwater beauty. There were many different forms of life including colorful fish, different types of coral, white sand and lots of activity. The large schools of neon colored fish swam so close you could almost reach out and touch them. It was so beautiful I could explore the reef for hours.

The marine world is a vast ecosystem depending on many communities existing in harmony. Marine Biology can be branched off many ways. Coral reefs are one of the largest branches and play a major role in the marine ecosystem. They are necessary to many forms of marine life, consequently the reefs are in great danger due to mankind and natural destruction.

There are scientists, students and other interested parties working to preserve the reefs. The coral reef is an elevated part of the ocean floor in relatively shallow waters. Reefs are formed by rock like accumulation of calcareous exoskeletons, calcareous red algae and mollusks. They have built up layer by layer of living coral growing upward at rates of one to one-hundred centimeters per year. The reefs live in tropical regions starting about 30 north and south of the equator. (Darwin) About 200 to 450 million years ago the soft bodied invertebrates evolved making the coral reef the oldest and largest living community on earth.

The inner layer of the reef is composed of non-living matter and the upper layer is composed of transparent polyps that grow on the remains of the once living polyps. The polyps are remarkable creatures that range in size from a small seed to as big as a lily pad and secrete calcium carbon at that forms tiny cup shaped homes. (Hinrichsen p. 554-555) The reefs play a large ecological role by cycling nutrients from swamps and sea grass beds to open ocean fisheries. Many plants and animals living on the reef produce chemicals used in medicines and pharmaceuticals. The reefs bear many sources of animal protein such as fish, shell fish and mollusks for more than one billion people. They also help to stabilize and prevent shoreline erosion.

(Hinrichsen p. 555) There are many types of coral reefs that make up the reef population. Three main categories of reefs are fringing reefs, barrier reefs and atoll reefs. Fringing reefs exist off the shore of an island or mainland containing no body of water between the reef and land. Further off the shore, barrier reefs exist with a channel between the reef and shore. The Great Barrier Reef consists of a chain of coral reefs in the Coral Sea near Australia's northeast coast.

Extending about two thousand kilometers from Mackay, Queensland to the Torres Straight makes this the largest deposit of coral in the world. Some northern areas of the reef are as close as 16 kilometers to the shore and reach a width of about 240 kilometers. The reef supports more than 1000 species of fish and many other organisms. ("Great Barrier Reef") Atolls are narrow coral islands typically horseshoe shaped with a shallow lagoon. (Hinrichsen) There are many other types of coral organisms varying in size, shape and color. These include stag horn coral, bulging brain coral, button corals, fire corals, lace corals, bead corals, organ pipe corals and vase corals.

The name of the coral is indicative of the shape it produces. Another key reef species are the sponges. The sponges act as a lung for the reef, clinging and recycling the water. The reefs depend a great deal on the abundance and coexistence of the sponge. (Hinrichsen) The coral reef is endangered in many aspects from both mankind and nature itself. Each year, thousands of tourists visit the coral reefs hoping to take back a piece as a souvenir.

"Ten percent of the reefs are already degraded beyond recognition, and thirty percent are in critical condition. Clive Wilkinson, a coral reef expert at the Australian Institute of Marine Science in Townsville, has concluded that if nothing is done to conserve and manage coral reefs, we may well lose seventy percent of them worldwide within forty years". (Hinrichsen) Because the reefs exist are in great abundance, they are becoming a popular vacation spot. Yet, studies show as the reefs are becoming more well known they are in more danger of disappearing. "A survey of 735 reefs carried out in 1991 found that seventy percent of the coral cover on those reefs was in fair to poor condition with less than fifty percent live coral cover. Only five percent of the cover remains in excellent condition".

(Coral) Mankind is the single largest threat to the reef. The reefs are being destroyed not only by fishermen using dynamite and poison but also by fine mesh nets and by carelessly dropped boat anchors. When we were snorkeling last spring in the Bahamas, the guide told us it was illegal to touch or take any portion of the reef while we were exploring. However, I am sure that not all tourists adhered to their requests and I could see places where coral had been broken off. We are also using them for cement production and production of roadbed material. Industrial pollutants are killing coral along with untreated sewage and municipal waste from urban and tourist areas.

Dynamite fishing is a way of life by some Luzon fishermen. The dynamite causes great destruction of the coral reef by breaking it into pieces and killing many species that inhibit normal growth. A new kind of fishing called cyanide fishing has become very popular in the last few years. Fishermen equipped with masks and snorkel's dive to the reefs squirting poison to push out hiding fish, killing and crippling coral and organisms in the process.

Cyanide stuns the fish causing them to flee which are then captured by collectors. Poisoned reefs soon turn white and lifeless. Cyanide fishing has recently become popular because of the growing interest in private salt water aquariums. (Hinrichsen) Aquarium owners and dealers are paying top dollar for tropical reef fish, therefore making cyanide fishing a profitable business yet it is destroying the coral reef. The same tropical reef fish are in great demand by southeast Asia and China restaurants that are offering diners their choice of live exotic reef fish as a delicacy. For example, grouper and hump head war sse have jumped from as little as $5 per pound to $60 per pound.

Nature travels on its own course through time by not only creating but destroying the coral reefs. All reefs are constantly under threat by natural sources including storms, pathogens and bleaching. Another threat to the reefs, possibly attracted by nutrient pollution from urban areas, the crown-of-thorns starfish are attacking the reefs. These starfish can be up to one-half meter in diameter and have thorn like appendages containing poison. The starfish attach themselves to the reefs injecting poison into the coral homes of the polyps, dissolving them, as the starfish extrudes its stomach through its mouth sucking up the remains of the polyps.

Each starfish can ingest its own body area in coral each day. Large infestations can literally destroy a large amount of reef in as little as four or five days. (Hinrichsen) When we were snorkeling last spring, you could actually hear other fish eating or chewing on the reef when you were under water. Since many businesses, hotels and tourist attractions profit by attracting tourists to the reefs, communities have made efforts to safeguard the reefs from any further destruction from the crown-of-thorns starfish. Scientists and many other interested parties are doing as much as they can to help the recovery and to preserve the remaining reefs. A good example of a recovery management program is the Great Barrier Reef Marine Park in Australia.

This park stretches out for more than 2000 kilometers along the coast of Queensland making it the largest reef complex in the world. The park was founded in 1975 in response to the public outrage of oil drilling and mining on the reef. Administers of Marine Park divided the entire area into four huge management areas. The park then subdivided each area into three categories: general use zones where nearly everything is permitted except spear fishing, mining and oil drilling; national park zones, which are look-but-don't-touch zones; and restricted zones where only scientific research is allowed. Supporters of the park have helped to keep the Great Barrier Reef one of the best managed marine ecosystems in the world. (Hinrichsen) On June 14, 1997, over 500 recreational scuba divers helped launch a survey of reef health.

Divers using measuring tapes and underwater writing utilities recorded many aspects of the reef's health. The survey took place around the world in many shallow water tropical reefs. Divers took a one hour training session with reef scientists to learn basic survey methods on how to identify common species. Then small groups were sent out to the reefs for a one time survey.

The divers were counting and measuring living things along with noting dead, dying or diseased coral. (Bischof p. 1494) "In response to the growing understanding, the US Department of State, in close cooperation with the US Agency for International Development, proposed the idea of international initiative for coral reef protection in 1994". (Hinrichsen) US joining with governments from Australia, France, Japan, Jamaica, The Philippines, Sweden and the United Kingdom all worked together in protecting the coral reefs by launching the International Coral Reef Initiative. The initiative can only achieve solutions by the interaction of local and national governments.

Data shows approximately less than one-half of the nations are protecting reefs adequately. (Hinrichsen) The greatest obstacle in managing reefs is a lack of public, political and media awareness concerning problems of the coral reef because they are out of sigh and out of mind. The reefs play a role as natural fish farms, wave breakers, shore defenders and leisure areas whether we see them or not and should be preserved. Preservation of these great ecosystems should be taken into strong consideration for future generations.


Work Cited Bischof, Barbie. "Scientists Launch Survey of Reef Health". Science 276. June 6, 1997: p.
1494. "Coral Reefs". Encarta Encyclopedia. 1995-96 ed.
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Darwin, Charles. The Structure and Distribution of Coral Reefs. Berkley: UP of California Press, 1962.
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Hinrichsen, Don. "Coral reefs in crisis". Bioscience Oct. 1997: p.