Wetlands

Wetlands

"Wetlands" is the collective term for marshes, swamps, bogs, and similar areas. Wetlands are found in flat vegetated areas, in depressions on the landscape, and between water and dry land along the edges of streams, rivers, lakes, and coastlines. Wetland areas can be found in nearly every county and climatic zone in the United States. Inland wetlands receive water from precipitation, ground water and/or surface water. Coastal and estuarine wetlands receive water from precipitation, surface water, tides, and/or ground water. Surface water sources include runoff and stormwater.

Since the 1600s, more than half of the original wetlands in the lower 48 states have been destroyed. Twenty two states have lost at least 50 percent of their original wetlands. Indiana, Illinois, Missouri, Kentucky, Louisiana, and Ohio have lost more than 80 percent of their original wetlands and California and Iowa have lost nearly ninety-nine (99 percent) percent. Since the 1970s, the most extensive losses of wetlands have occurred in Louisiana, Mississippi, Arkansas, Florida, South Carolina, and North Carolina. Wetlands have been drained and converted to farmland, filled for housing developments and industrial facilities, and used as receptacles for waste. Human activities continue to adversely affect wetland ecosystems.

More recently, society has begun to understand the functions of wetlands and the values humans obtain from them. Wetlands help regulate water levels within watersheds; improve water quality; reduce flood and storm damages; provide important fish and wildlife habitat; and support hunting, fishing, and other recreational activities. Wetlands are important features in watershed management. The characteristics of wetlands are ...

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Another cause of wetland depletion are industry. Adverse effects of industry on wetlands can include: reduction of wetland acreage, alteration of wetland hydrology due to industrial water intake and discharge, water temperature increases, point and non-point source pollutant inputs, pH changes as a result of discharges, and atmospheric deposition. Saline water discharges, hydrocarbon contamination, and radionuclide accumulation from oil and gas production can significantly degrade coastal wetlands (Rayle and Mulino 1992). Most petroleum hydrocarbon inputs into coastal wetlands are either from coastal oil industry activities, from oil spills at sea, from runoff, or from upstream releases (Kennish 1992). Oil can alter reproduction, growth, and behavior of wetland organisms, and can result in mortality. Plants suffocate when oil blocks their stomata (Dibner 1978).