I know I waxed a bit poetically about the Great Barrier Reef today....if your interest was piqued at all, check out this website with some simple info about the reef, and a cool little short video!
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Diving at the Great Barrier Reef in Australia
The Environmental Impact of Humans on Coral Reefs:
ReplyDeleteWhen most people think of corals, they think of tropical islands, colorful fish and clear waters. This is because the $1 billion dollar tourism industry is largely fueled by coral reefs and the 4,000 plus species of fish and marine life that coral reefs harbor. Often, coral reefs are recognized as "the rainforests of the ocean". Coral reefs are one of the world's most productive ecosystems. Corals are polyps, or tiny, genetically identical, individual animals, who belong to the group cnidaria (which include hydra, jellyfish, and sea anemones). They secrete calcium carbonate, which becomes the foundation for an external skeleton which they sit on. Thanks to an intricate symbiotic (mutually beneficial) relationship with the algae that live within their bodies, they have been a highly successful life form for 250 million years.
In the past 25 years, however, coral reefs around the world have been collapsing. Some recent estimates suggest that 20% of the world's coral reefs are already dead and an additional 24% are dangerously threatened. The impact on reefs in a consequence of a number of factors including climate change, changes in ocean temperature, pollution, ocean acidification caused by the absorption of carbon diozide into sea water, coral bleaching (the loss of symbiotic algae that are essential for healthy grouwth of coral colonies), over-fishing, sedimentation, oxidative stress and disease, and many other destructive activities that humans have brought about. An interesting article, "Why Coral Reefs Around the World are Collapsing", contends that the major reason for the recent downfall of coral reefs is that the symbiotic relationship between the algae and coral, which is based on a delicate method of communication, is breaking down. Normally, the algae tells the coral through a sophisticated system of biological communication, that it belongs there and that everything is fine. Without this message, the corals would treat the algae as a parasite or invader and try to kill it.
Virginia Weis, a professor of zoology at Oregon State University, speaks of this unique internal language: "Even thought the coral depends on the algae for much of its food, it may be largely unaware of its presence." She continues, "We now believe that this is what's happening when the water warms or something else stresses the coral- the communication from the algae to the coral breaks down, the all-is-well message doesn't get through, the algae essentially comes out of hiding and faces an immune response from the coral." Experts hope that because of the amazing variation of species of coral and algae (thousands of each species) that take part in this symbiotic relationship, combinations will be found to adapt better to the changing conditions of oceans because of human activity.
Works Cited:
ARC Centre of Excellence in Coral Reef Studies (2009, May 12). Rules Proposed To Save The World's Coral Reefs. Science Daily. Retrieved July 15, 2009, from http://www.sciencedaily.com- /releases/2009/05/091511101735.htm
Carnegie Institution (2009, March 10). Coral Reefs May Start Dissolving When Atmospheric Carbon Dioxide Doubles. Science Daily. Retrieved July 15, 2009, from http://www.sciencedaily.com- releases/2009/03/090309162125.htm
Oregon State University (2009, May 29). Why Coral Reefs Around The World Are Collapsing. ScienceDaily. Retrieved July, 5, 2009, from http://www.sciencedaily.com- /releases/2009/05/090528142819.htm
U.S. Environmental Protection Agency, Coral Reef Protection. Retrieved July 26, 2009, from Habitat Protection Web Site: http://www.epa.gov/cgi-bin/epaprintonly.cgi
Wiley - Blackwell (2009, June 27). Corals Stay Close to Home. ScienceDaily. Retrieved July 15, 2009, from http://www.sciencedaily.com- /releases/2009/06/090626084636.htm