Coral reefs are complex and diverse habits. Perhaps one of the largest and most important marine biomes. Yet it is a relatively small biome, about 25% of the marine species that belong to the oceans live in coral reefs. Coral reefs are an underwater structure composed of calcium carbonate, a secretion from corals. A significant portion of the world's coral reefs form near the equator along coasts and are found around islands around the world. Coral reefs come in a variety of shapes, sizes, and colors, but coral reefs are recognized by three main types: Coral Reef, Coral Reef, and Atoll. In addition to being a beautiful and interesting colorful ecosystem or tourist attraction, coral reefs are an important element of our ecosystem. According to NOAA National Ocean Service Education (2008), “a coral reef is an important element in the most diverse ecosystem on earth. From serving as protection and refuge for many different species of fish to controlling the amount of carbon dioxide produced in the ocean and ultimately protecting the coast from strong currents and waves by slowing the water before it reaches the shore.” Many different marine species rely on coral reefs for habitat and food sources, including several endangered species. However, this world does not realize the critical importance of these coral reefs as most of the coral reefs are struggling or dying across the world. It is estimated that 30% of coral reefs are already severely damaged. By 2030, nearly 60% of our coral reefs will be lost (Hughes et. al., 2003, p. 929). Human activity, particularly towards coral reefs, has a global impact. More recently climate change has developed and has now become one of the...... middle of paper ......ty of the global threat to coral reefs. Biosciences, 57(3), 214-215. Retrieved from http://search.proquest.com/docview/216479754?accountid=40611Hay, M., & Rasher, D. (2010). Corals in crisis. The Scientist, 24(8), 43-46. Retrieved from http://search.proquest.com/docview/748811502?accountid=40611Hinrichsen, D. (1997). Coral reefs in crisis. Biosciences, 47(9), 554-558. Retrieved from http://search.proquest.com/docview/216465718?accountid=40611Hughes, T.P., Baird, A.H., Bellwood, D.R., Card, M., & al, e. (2003). Climate change, human impacts and coral reef resilience. Science, 301(5635), 929-33. Retrieved from http://search.proquest.com/docview/213584148?accountid=40611What are the three main types of coral reefs?. (2014). National Oceanic and Atmospheric Administration. Retrieved from http://oceanservice.noaa.gov/facts/ threecorals.html