Coral Reef Biome

Bio
9/12/10
Coral Reef Biome

Though not considered a major biome, coral reefs qualify by definition. Coral reefs are marine ecosystems located within clear, shallow water. These reefs require water between 25 and 31 degrees Celsius, and do well in water with a salinity of 34 and 37 parts per 1000. These conditions are most often found within 30 degrees latitude of the equator, or in other words, the tropics. As the name suggests, corral reefs are formed by colonies of coral polyps. Coral polyps secrete calcium carbonate (limestone) which forms the reefs. The polyps receive oxygen and nutrition through photosynthesis preformed by zooxanthellae algae. The necessity of large amounts of sunlights further restricts the environments in which these reefs can flourish. Reefs develop into three different formations. Fringing reefs occur along shorelines, and are frequently found on Hawaii and the Caribbean. Barrier reefs are formed offshore, and occur often in the Indo-Pacific and Caribbean. Atolls are reefs surrounding a lagoon, and are commonly found in the Indo-Pacific. Though different in appearance and location, each reef is part of the larger coral reef biome. http://oceanworld.tamu.edu/students/coral/coral2.htm http://www.cotf.edu/ete/modules/coralreef/CRcoralreefs.html

Coral reefs take up less than one percent of the ocean floor, yet are home to over 25 percent of its known species. Due to these many populations, species who inhabit the reefs have adapted in different niches. The Parrotfish bites off branches of coral and uses its powerful mandibles to gnaw out the polyps. Other organisms, such as the Damselfish, rely upon the coral as a place of refuge. If frightened the Damselfish will retreat to the coral passageways and remain there until reassured of its security. On the other end of the spectrum, reef species such as the Bird Wrasse have evolved long, trunk-like snouts useful for extracting prey from hard to reach nooks. The sheer quantify of organisms competing for the same habitat have resulted in coral reefs housing some of the most intricate ecosystems, but also some of the most adapted. http://www.marinereef.org/reports.php?reportid=4 A fragile biome, scientists suggest that already ten percent of the earth's coral reefs have been destroyed or irrevocably damaged, and another 60 percent are in danger. The cause of coral deterioration cannot be placed solely on one cause, but is the result of a multitude of damaging factors. As coral polyps themselves rely upon zooxanthellae algae to receive oxygen and minerals, the absence of this algae results in the death and deterioration of both coral polyps and coral reefs. Sensitive to temperature and ultra violent radiation, coral polyps expel the algae living within them when stressed by overexposure to the sun or un-customarily high water temperatures, both results of global warming. Also threatening these reefs is the development of coastal areas. Not only does this construction directly damage the reefs through the building of piers and other structures, it also indirectly leads to sedimentation. Erosion cause by the development smothers the coral and deprives it of the necessary sunlight it requires to survive.
http://www.coral.org/resources/about_coral_reefs/threats_to_coral_reefs