|September 12, 1997||Ken Burton 202-208-5634
Diana Hawkins 404-679-7289
The United States is continuing to lose wetlands, but the loss has slowed to a rate 60 percent below that experienced in the 1970s and 1980s, according to a new U.S. Fish and Wildlife Service report released today.
While wetlands restoration and creation activities have contributed to the national wetlands base, the study showed a net loss of 117,000 acres per year between 1985 and 1995, much of which occurred in highly productive, freshwater, forested wetlands. "Wetlands are crucial to the health of our environment," said Jamie Rappaport Clark, Director of the Fish and Wildlife Service. "The study shows that our Nation's efforts to restore and protect wetlands are making a difference."
The U.S. Fish and Wildlife Service's National Wetlands Inventory measures wetland loss, which occurs when a wetland ceases to be a wetland. A wetland gain occurs only when a non-wetland becomes a wetland. Those changes are measured and reported in terms of acres. In the 200 years between the 1780s and 1980s, the land mass constituting the 48 contiguous United States lost 54 percent of the estimated original 221 million acres of wetlands--a loss amounting to about 60 acres per hour for 200 years. Between the 1950s and 1970s, the Lower 48 States lost an estimated 458,000 acres of wetlands each year; from the 1970s to the 1980s, the annual loss amounted to about 290,000 acres.
The report, "Status and Trends of Wetlands in the Conterminous United States," is required by Congress at 10-year intervals. Because wetlands losses influence other ecological interests, the Service provides scientific data needed for research, management, and policy decisions regarding the remaining wetland base. The report also helps resource managers gauge the success of efforts to protect and restore wetlands.
Other important findings of the current study include:
Wetlands are lands where the water table usually is at or near the surface or where the land is covered by shallow water. Most wetlands in the United States are located in the Southeast coastal plain, Lower Mississippi Valley, the Prairie Potholes Region, Great Lakes States, and in upper New England. Such lands have been called "the cradle of life" for waterfowl, fisheries, endangered species, countless small birds, mammals, and a wide variety of plant life. Wetlands catch and hold floodwaters and snow melt, recharge groundwater, and act as natural filters to cleanse water of impurities.
Service scientists liken wetland restoration to healing because restoration actions are usually performed on degraded acreage that continue to display some wetland characteristics. Restoring wetland functions to sites that retain some wetland characteristics is more feasible, less expensive, and more likely to succeed than at sites lacking wetland characteristics. While functions are replaced or increased by wetland restoration actions, the total acreage of existing wetlands on the landscape does not increase in proportion to the acreage restored. Even a net gain of 50,000 acres a year, the scientists said, would require more than 40 years of sustained effort to replace only 1 percent of the Nation's original wetland acreage.
Factors contributing to the marked decline in the loss rate include implementation of the
Section 404 program of the Clean Water Act; state and local wetland regulatory programs; increased public awareness and support for conservation; expansion of Federal, state, local, and private-sector restoration programs that have contributed 78,000 acres a year to the national wetlands base; enactment of Swampbuster measures in the Farm bills since 1985; and a decline in the profitability of converting wetlands due to the tax reform of 1986. (The section 404 program, among other things, prohibits the placement of dredged or fill material into an aquatic ecosystem unless steps have been taken to minimize adverse effects).
While wetlands compose only about 5 percent of the land area in the conterminous United States, they vary widely in location, size, and type. Because a complete inventory would be prohibitive-ly costly, the status and trends report employed a sampling approach, using 3,726 plots, each
4 square miles in area. The Service obtained high-quality, color infrared photographs through the National High Altitude Program for 2,682, or 72 percent, of the sample plots, and compared the photographs with those of the previous decade. For plots where aerial photography was unavailable, the Service used mathematical projections to complete the study.
For the purposes of the Service study, different types of wetlands were grouped into the following three categories:
Saltwater Habitats: Salt marshes, open water, mangroves or other shrubs, beaches, and some river deltas are included in this category. These areas are formally known as Marine Intertidal, Estaurine Subtidal, and Intertidal systems. Marine Intertidal includes areas in which the land is exposed and flooded by tides. Estaurine Subtidal is land continuously submerged, and riverine includes wetlands and deepwater habitats contained within a channel. About 5.1 million acres, or 5 percent, of remaining wetlands are saltwater.
Freshwater Habitats: Forested swamps, shrub wetlands, inland marshes and wet meadows, shore beaches, open water ponds, floating or submerged vegetation and lakes and reservoirs. These areas include six Palustrine categories, which are all nontidal wetlands not included in any other system, and the Lacustrine system, which consists of open water and associated wetlands. Some 95.8 million acres, or 95 percent, of remaining wetlands are freshwater.
Upland Land Use: Crop agriculture and pasture, cities and incorporated developments, and rural uplands not in agriculture or pasture and all other areas not considered wetlands or deepwater habitat.
Unvegetated intertidal wetlands, freshwater shrub wetlands, and freshwater ponds all experienced acreage gains between 1985 and 1995. Agricultural activity, while showing an improvement over wetlands loss rates in the past, still showed a decline of 924,000 acres, or
79 percent of the 1985-1995 total. Urban and other development accounted for the remaining
21 percent of the total loss recorded for the same period. Unvegetated intertidal wetlands gained acreage due to coastal storms, shoaling of sand, beach renourishment, and dredging. Freshwater shrub areas gained because forested wetlands were cut, and subsequently converted to shrub wetlands.
Ponds experienced gains as more were created for water retention for farms, for ornamentation in some developments, as water traps on golf courses, and small residential lakes, all less than 20 acres in size. There are now 5.2 million acres of ponds in the U.S. Urban development accounted for the loss of 6 percent of the total, but developers also created some of the 15,000 acres of freshwater ponds.
Americans can help wetlands when they purchase a $15 Federal Duck Stamp at their neighborhood Post Office and at other locations. The money is used by the U.S. Fish and Wildlife Service to protect wetlands and other wildlife habitat that is part of the National Wildlife Refuge System.
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