Coral Reefs Essay -- Ecology Environment Environmental Essays

Coral Reefs   Ã‚  Ã‚  Ã‚  Ã‚  Coral reefs are one of the oldest types of living systems on earth, and certainly one of the most spectacular (Goreau, 1987). They are massive underwater structures formed by the limestone skeletons of tiny invertebrate animals. Reefs house a greater diversity of body forms, chemistry, and animal phyla (thirty-two compared to the eight that inhabit the most biodiversity ecosystems on land). Phyla comprise the second largest category of living things, after kingdoms.   Ã‚  Ã‚  Ã‚  Ã‚  Coral animals begin life as free-floating larvae, but settle on the sea floor in sedentary colonies. The term "coral" applies both to these animals and to their skeletons, particularly the skeletons of stone-like corals (Discover 1997).   Ã‚  Ã‚  Ã‚  Ã‚   Many different organisms, including mollusks, sponges, and worms, help shape reefs, but hard corals and various algae are the major architects. In effect, the corals build limestone, because their skeletons are made of Calcium Carbonate. The skeletons deposited by these corals and other organisms accumulate, along with sand and other debris, to form the backbone of the reef. Over tens of thousands of years, chemical and mechanical changes turn the reef into true rock (Alstyne and Paul, 1988).   Ã‚  Ã‚  Ã‚  Ã‚   The body of a coral animal consists of a polyp, which is the living portion of the coral. A polyp is a hollow, cylindrical structure attached at one end to a surface, the other end is a mouth surrounded by tentacles, which gather food and can sting prey to paralyze it. Polyps live in colonies, which grow from 1 to 7 inches, depending on the species. Coral polyps are classified as animals. Microscopic algae live within the animal tissues in a symbiotic relationship. The algae turn sunlight into carbon and sugars, which are then available to the polyp. In turn the polyp filters particles out of the water and excretes waste (nitrogen and phosphorus) that becomes available to the symbiotic algae. It's this very tight nutrient recycling within the coral itself that allows these corals to live in very low nutrient waters.   Ã‚  Ã‚  Ã‚  Ã‚   There are three kinds of reefs: atolls, barrier reefs, and fringing reefs. Atolls are formed out in the middle of the ocean by volcanic subsidence, while fringing and barrier reefs form near continents. Florida contains both of these kinds of reefs, not as far offshore as Australia's Great Barrier Reef, b... ...al life. Another way that corral growth is controlled is by the weather. All of these are natural occurrences. This should not be confused with human use and disruption which does major harm.   Ã‚  Ã‚  Ã‚  Ã‚  The fourth and final principle of sustainability is that biodiversity must be maintained. This is where we are playing a devastating role to the survival to the reefs. Through human waste and consumption time will only tell if they will survive. I hope that by reading this paper someday we can make a difference. Works Cited: â€Å"Coral Color.† November 1997. Discover Magazine-Current Clips. P10 Cousteau, J. Y. 1985. The Ocean World. Harry N. Abrams, Inc., New York, NY, pp. 174-175. Goreau, Thomas. August 1987. â€Å"Coral and Coral Parks.† Scientific American. V113:34-36 Luoma, Jon R. Nov. 1996. â€Å"Reef Madness† Audubon. V98: n6. P24(3). Richmond, R. H. 1993. â€Å"Coral Reefs: Present problems and Future Concerns Resulting form Anthropogenic Disturbance.† American Zoologist. V33: P524-536. Van Alstyne, K. L. and V. J. Paul. 1988. â€Å"The Role of Secondary Metabolites in Marine Ecological Interactions.† Proceedings of the 6th International Coral Reef Symposium, Australia, Vol. 1.