Earth Talk: Wetlands Loss
PHOTO CAP: "The continental U.S. has lost almost 120 million acres of wetlands since European settlement in the early 1600s; Canada has lost roughly 50 million. Major factors today include agricultural expansion, road building, residential development and the building of large facilities like shopping malls, factories, airports and, ironically, reservoirs." Image Credit: "Getty Images."
Dear EarthTalk: What is the status of wetlands in North America? Years ago I remember that wetlands loss, due to development and sprawl, was accelerating fast, but I haven't heard much on the topic of late. -- John Mossbarger, La Jolla, CA
Wetlands serve as primary habitat for thousands of wildlife species-from ducks to beavers to insects-and form an important ecosystem link between land and water. They also play a key role in maintaining water quality, as they filter out agricultural nutrients and absorb sediments so that municipal water supplies don't have to. On and near shorelines, wetlands provide a natural buffer against storm surges and rising floodwaters, helping to disperse and absorb excess water before it can damage life and property.
The eradication of wetlands in the so-called New World began when white settlers, intent on taming the land, started developing homesteads and town sites throughout what was to become the United States and Canada. Researchers estimate that at the time of European settlement in the early 1600s, the land that was to become the lower 48 U.S. states had 221 million acres of wetlands. By the mid-1980s, following another great period of loss after World War II when army engineers drained huge swaths of formerly impenetrable marshes and swamps, the continental U.S. had only 103 million wetland acres remaining.
Across the U.S. and Canada, the vast majority of wetlands-about 85 percent-have been destroyed in the name of agricultural expansion. Other major factors include road building, residential development, and the building of large facilities like shopping malls, factories, airports and, ironically, reservoirs.
But growing awareness about the importance of wetlands has led to new regulations aimed at protecting those that remain. A variety of state and federal programs, such as the U.S. Department of Agriculture's Wetland Reserve Program (whereby landowners voluntarily protect, restore and enhance wetlands on their own private property), have been effective in stemming the tide of wetlands loss. During the 1990s the rate of wetlands loss in the U.S. declined by some 80 percent over previous decades. But the nation is still losing upwards of 50,000 wetland acres per year, according to the U.S. Fish & Wildlife Service.
The issue is of even greater concern in Canada, which harbors a quarter of the world's remaining wetlands in its northern boreal forests. According to Natural Resources Canada, fully 14 percent of Canada's total land mass is in the form of wetlands. Researchers believe that about 50 million acres of wetlands have been lost in Canada since European settlement. Underscoring the correlation between urbanization and wetlands loss, less than .2 percent of Canada's wetlands lie within 25 miles of major urban centers today.
On the global level, 158 governments are signatories to the 1971 Ramsar Convention on Wetlands, an international treaty that provides a framework for international cooperation in the conservation and wise use of wetlands. Some 1,743 wetland sites-totaling almost 400 million acres-have been protected as "Wetlands of International Importance" under the terms of the treaty. Although the Ramsar treaty can do little to stop illegal or legal draining of wetlands, its very existence highlights how seriously the majority of the world's countries take protecting land formerly thought of as God-forsaken and useless.
Contacts: Wetlands Reserve Program, www.nrcs.usda.gov/Programs/WRP/; Natural Resources Canada, www.nrcan-rncan.gc.ca; Ramsar Convention on Wetlands, www.ramsar.org.
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