One of the greatest debates going on about the coastal wetlands in Louisiana is whether or not the hurricanes, specifically Hurricane Katrina and Hurricane Rita in 2005, have impacted the land loss. Hurricanes are classified as disturbances. Disturbances, in scientific terms, can be defined as periodic and destructive events that cause change to an ecosystems and causes affects to the organisms within it either positively or negatively.
Obviously, hurricanes would affect the ecosystems of animals and vegetation in a negative way, not to mention humankind as well. However, there is a silver lining in what wetlands offer to such a destructive force. Wetlands traditionally can help be a buffer for hurricanes to damage onto the mainland. The vegetation of the wetlands helps spread rain and flood water on a more equal level. In an article published by Erin St. John she mentions the wetlands water capacity also can reduce erosion and lowers the heights of flooding, all of which have a deep impact on the destruction from hurricanes.
The problem with wetlands being destroyed is that helped in exacerbating the destruction from Hurricane Katrina and Hurricane Rita. Typically speaking, the damage from a hurricane comes in the form of large amounts of water flooding into the city. In an interview posted on MSNBC.com Sidney Coffee, executive assistant to the governor for coastal activities, states that “for every 2.7 miles of wetlands, storm surges are reduced by about one foot.” Hurricane Katrina and Hurricane Rita were both category five storms, the strongest classification of hurricanes.
While natural disturbances are a force that causes great destruction, the wetlands are also being eroded by the creation of man-made levees. Robert Morton explains this in his article “An Overview of Coastal Land Loss: With Emphasis on the Southeastern United States”:
Except for infrequent episodic deposition associated with hurricanes, marsh deposition rates are lowest in the summer and also in the spring. In Louisiana, low rates of sediment deposition are a result of flood control structures and levees on the Mississippi River and its distributaries. Before river control, spring floods annually delivered large volumes of suspended sediment across the delta plain helping maintain marsh elevations even on inactive delta lobes.
Man-made levees also can cause further damage when they are destroyed, as evident from Hurricane Katrina. When levees are destroyed the flood water that results can destroy both wetlands and the main land depending on the amount of water being held back by them. The wetlands are affected dramatically by disturbances, both natural and man-made ones. The affects of both can be devastating to humankind and other animals and organisms.
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Great examples.
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