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Three Gorges Dam in ChinaIn China, The Yangtze River branches out into a broad estuary that stretches 655 kilometers into the East China Sea, and forms one of the largest continental shelves in the world. Over half of the Yangtze's annual sediment load is deposited in the estuary. The health of the estuary depends on the delivery of this sediment because a significant relationship exists between inter tidal wetland growth rate and riverine sediment supply. Yet, due to the Three Gorges project and other dams, the sediment accumulation rate in all reservoirs on the river has increased from close to zero in 1950 to more than 850 * 106 tons per year in 2003. This is causing erosion of the wetland habitat there, which provides nurseries for fish and resting areas for migratory birds and is considered one of the world's most important wetland ecosystems. There is also concern about the impact the project will have on biological diversity. The baiji dolphin, the ancient river sturgeon, and the finless porpoise depend on the Yangtze for their survival. The population of Siberian cranes in Poyang Lake will also be affected by the dam (Cleveland 2007).
Coral Reefs !GrecianRocks.1965.jpg|width=547,height=358!A star coral. Source: USGS
Coral reefs are unique and beautiful ecosystems. They have the most species per unit area of any marine environment and hold perhaps 1-8 million as of yet undiscovered species (Reaka-Kudla, 1997). These species hold great promise for new pharmaceuticals (NOAA) and also provide goods and services worth $375 billion per year, despite their only covering under 1% of the Earth's surface (Costanza et al, 1997). Developing countries rely on coral reefs for approximately ¼ of total fish catch (Jameson et al, 1995). Coral reefs offer benefits to people living in coastal areas by acting as buffers to wave action; they may also protect coastal wetlands (NOAA).
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