Wetlands are among the most productive ecosystems in the world. A wetland is an area of land where water covers the soil, for all or a portion of the year. Wetlands come in many forms including swamps, marshes, estuaries, mudflats, lakes, lagoons, ponds, deltas, coral reefs, billabongs, shallow seas, floodplains, and more. No matter the shape or size, wetlands provide numerous important services for people, fish and wildlife such as protecting and improving water quality, providing habitats for fish and wildlife, storing floodwaters, maintaining surface water flow during dry periods, and reducing soil erosion.
Although wetlands are often thought of as “wet”, a wetland might not be covered in water year-round. In fact, some of the most vital and biologically diverse wetlands on earth are only seasonally wet. Wetlands form as a result of certain hydrologic conditions which cause the water table to saturate the soil. A wetland can be thought of as a natural sponge that absorbs and slowly releases surface water, rain, snowmelt, groundwater and flood waters that need storing. The water within a wetland may be static or flowing, fresh, brackish, saline, or even underground.
Wetlands serve as a vital link between land and water. Even in urban cities, wetlands play a larger role than many of us realize. They reduce flooding, replenish our drinking water, filter out waste and pollutants, provide urban green spaces, and are a source of livelihoods.
Wetlands also provide benefits to industry. For example, they form nurseries for fish and other marine life and are critical to commercial and recreational fishing industries. More than one-third of the United States' threatened and endangered species live only in wetlands, and nearly half directly use wetlands at some point in their lives. Therefore, when a wetland is compromised, it can wreak havoc on entire ecosystems, to the point of collapse.
Causes of Wetland Loss
Like many other environmental issues that we face in our world today, much of the root causes of global wetland depletion are anthropogenic, resulting from the influence of human beings on nature. For example, one of the leading causes of wetland impairment is urbanization, which has resulted in direct loss of wetland acreage as well as degradation of wetlands. Other major sources of wetland loss and degradation include hydrologic alterations, industry (including industrial development), marinas/boats, agriculture, silviculture/timber harvest, mining, and atmospheric deposition.
But how? Each of the above sources of wetland loss and degradation impose some level of unwarranted change on the environment. In a fragile ecosystem, degradation can result from changes in water quality (often through increases in pollutant inputs), changes in water quantity and flow rates, and/or changes in species composition as a result of introduction of non-native species or disturbance.
In the 1600's, over 220 million acres of wetlands existed in the lower 48 states. Since then, extensive losses have occurred, with many of the original wetlands drained and converted to farmland. Today, less than half of the nation's original wetlands remain.
Each year, on February 2nd, we celebrate World Wetlands day, the anniversary of the signing of the Convention on Wetlands of International Importance in Ramsar, Iran, in 1971. World Wetlands day was first celebrated in 1997. Since then government agencies, non-government organizations and community groups have celebrated this day by undertaking actions to promote the conservation and wise use of our wetlands. This year’s theme for World Wetlands Day is “Wetlands for a sustainable urban future”. Join us in raising public awareness of wetland values and benefits to help preserve these invaluable sources of life.