Coral reefs & bleaching
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Coral reefs & bleaching






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Coral reefs & bleaching Presentation Transcript

  • 1. SC-249 Environmental Concepts & Issues Taichi Kikuchi
  • 2. Outline1. What is Coral Reef?2. What is Coral Animal?3. Type of corals4. Phylum: Cnidaria5. The symbiotic relationship6. What is Coral Bleaching?7. Why do we have to care about Corals?8. How can we protect Corals from bleaching?9. Projects to survey and protect Corals10. References
  • 3. What is Coral Reef? “The coral reef is a unique shallow water community of organisms living on limestone rock that was built by some of the reef organisms (Lerman 426).” The main reef builders are corals and coralline algae. Marine organisms that secrete calcium carbonate such as clams, snails and sponges accumulate to form reefs after their death. In other words, a reef is a clump of calcareous rock derived from diverse organisms living on the reef.
  • 4. What is Coral Animal? Phylum : Cnidaria (same group as jelly fish, sea anemone) Corals inhabit in shallow, clear water within tropics. They have symbiotic tiny algae (zooxanthellae) within the body. In the daytime, they get nutrition via photosynthesis by zooxanthellae. They hunt for food at night with their tentacles. There are 215 scleractinian (58 genera) and 7 non- scleractinian corals in Palau (PICRC 12).
  • 5. Type of corals Solitary (mushroom coral)/ colonial corals Stony corals: brain, staghorn, antler, lettuce, and flower coral → They secrete a cup-shaped skeleton of calcium carbonate, called corallite. Soft corals(octocorallia): seafans, sea pens, whip corals →They secrete soft, flexible skeletons made of keratin. Abundant stony corals in Pacific reefs. Abundant soft corals in Caribbean reefs.
  • 6. Phylum: Cnidaria The classification of the major groups of coral animals
  • 7. The symbiotic relationship Corals excrete their wastes to tiny algae. The tiny algae produce nutrition for coral polyps.
  • 8. What is Coral Bleaching? Coral Bleaching = Corals which lost their symbiotic algae appear whitish. Corals are compelled to expel the algae because of its toxin when they are under stressful condition. Unusual high water temperature is thought as the main cause of the mass bleaching event in 1997~98. Some species can survive bleaching but the aftereffect includes slower growth, fragile body and higher risk of disease.
  • 9. Why do we have to care aboutCorals? Ecological value: corals sustain rich marine biodiversity. (ex. Shelter for some animals, food for other animals Economical value: tourism, fishery industry (ex. Divers, tourists, and food supply Environmental value: they provide protection for us. (ex. Breaking storm wave, tsunami, typhoon Coral reefs have a great importance for Palau in many aspects.
  • 10. How can we protect Corals frombleaching? Not to touch corals physically. Stop destructive actions such as dynamite fishing, over coastal development causing sedimentation. Have an interest on coral reef and take actions to spread knowledge. Proper instruction for any people trying to play around coral reefs.
  • 11. Projects to survey and protectCorals The Marine Protected Areas (MPAs) = the place where people are prohibited or restricted to enter and use resources. PICRC National Long-Term Coral Reef Monitoring Program in 2001 ・21 monitoring sites around the main islands ・Coral reefs are recovering for 3 years from 2001. ・It suggests that some species are more resistant to pressure.
  • 12. ReferencesMarshall, P and Schuttenberg, H. A Reef Manager’s Guide to Coral Bleaching. Townsville: Great Barrier Reef Marine Park Authority, 2006.Lerman, M. “Chapter 13 Coral Reefs.” Marine Biology. California: The Benjamin/Cummings Publishing Company, Inc, 1986.Palau International Coral Reef Center, and Japan International Cooperation Agency. Coral Reefs of Palau. Palau: Palau International Coral Reef Center, 2007.