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FYI
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Wetland Types: Technical Terms
Lacustrine System:
a type of wetland traditionally called by such names as lakes, playas, and reservoirs
Palustrine:
a group of vegetated wetlands such as marshes and swamps. Palustrine wetlands are typically dominated by trees, shrubs, and water grasses
Riverine:
a type of non vegetated wetland that is contained within a channel, which may be natural or human made
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Wetlands ecosystems are second only to the rain forests in the number of wildlife and plant species that
depend on them for feeding and habitat. Texas is one of four states, among the lower 48 states, with the greatest wetland acreage. Wetlands are defined "as
areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do
support, a prevalence of vegetation typically adapted for life in saturated soil conditions."* Wetlands include
marshes, swamps, bogs, playa lakes (shallow lakes), and can include floodplains, and mud flats.
Among their many valuable functions, wetlands filter pollutants that might otherwise flow into rivers, streams, or lakes.
Wetlands are often referred to as the "kidneys of the landscape." Riparian wetlands also help prevent erosion of
streambeds; their spongelike quality enables them to store heavy rains that could otherwise cause floods. Wetlands are
the breeding, feeding, and nesting grounds for many endangered species, including plants, and for nonendangered wildlife and natural communities.
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WETLAND LOSSES (1790-1980)
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The lower 48 states support only an estimated 104 million acres, or 47% of the
original acreage.
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Source: Texas Parks and Wildlife Department,
Texas Wetland Conservation Plan (1997), 32.
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Wetlands are also used for recreational activities, such as bird watching, canoeing,
fishing, and hiking. Wetlands may be located in cities, on farmland, in forests, and along coastlines and include both saltwater and freshwater systems. The economic,
environmental, and recreational value of wetlands is unmeasureable. The only continent on which wetlands do not exist is Antarctica.*
It is estimated that since European settlement of the lower 48 states, the United States has
lost more than half of its coastal and terrestrial wetlands. Today an estimated 100 million acres of wetlands exist. Though their disappearance continues, federal regulations, public
awareness, and restoration programs have in the past two decades slowed down the rate of loss. A report issued in 1997 by the Fish and Wildlife Service estimated that between the
1950s and the 1970s the lower 48 states lost 458,000 acres of wetlands annually, and from the 1970s to the 1980s the annual loss rate was approximately 290,000 acres annually. Between
1985 and 1995, the lower states lost 1.2 million acres cumulatively, or 117,000 acres annually. During this period, half of these losses occurred among the forested wetlands in the Southeast,
most of which were converted to pine forests (for lumber) or cropland. The Fish and Wildlife Service concluded that between 1985 and 1995, 79 percent of the total
wetland losses were due to agriculture.* On the other hand, in challenging the study methodology of the Fish and
Wildlife Service, the USDA attributes 58 percent of wetland loss during this period to urban development.* The Fish
and Wildlife Service also reported a loss of 2.5 million acres of forested wetlands from 1985 to 1995, compared with
4.8 million acres in the previous ten years. In 1995 there were fewer than 50 million acres of freshwater, forested wetlands in the lower 48 states.
Recognizing the tremendous importance of wetlands, the federal government in 1985 established a national goal of "no
overall net loss of wetlands." The Clean Water Act is the law that has had the greatest impact on wetlands. Section 404
of the Clean Water Act requires a permit from the Army Corps of Engineers for any dredging or filling into waters of the
United States. This includes both terrestrial and coastal wetlands. In 2001, however, the Supreme Court narrowed the
Clean WaterAct, stating that it did not apply to "isolated" wetlands because the Act refers to navigable waters. Other
U.S.Courts have reached different conclusions, but, if terrestrial wetlands,such as playa lakes, pot holes, bottomland
forests, which are not connected to navigable waters, are to be protected, new rules for the Clean Water Act must be
adopted to clarify how much connection, if any, wetlands must have to navigable waters.
Status of Wetlands in Texas
There are two major types of wetlands: inland/terrestrial wetlands and coastal wetlands. Coastal wetlands include
marshes and swamps. Inland wetlands include bottomland hardwood forest, shrub swamps, marshes, and lakes in East
Texas; springs, and riparian vegetation (pertaining to a river-bank) and playa lakes (shallow lakes), saline lakes, and
riparian habitats in West Texas; and individual ponds, pot holes, and "relic meanderings of the Rio Grande" in South Texas.* Inland wetlands account for 80 percent of the total wetland acreage in Texas.
- In the past 250 years, Texas has lost 60 percent of its most valuable inland wetlands: the riparian communities.* Most of the inland wetlands are on privately held properties.
- Texas has lost one-half of its coastal wetlands and 60 percent of its terrestrial wetlands in the past 200 years.
There is no state law to protect wetlands.
In the coastal management legislation of 1991, Texas legislators did incorporate a no-net-loss of wetlands policy for
state-owned land, but the majority of wetlands are on private lands. Wetlands comprise less than 5 percent of the state's total land area.
In 1994 the Texas Parks and Wildlife Department initiated the development of a state wetlands conservation plan that
focuses on nonregulatory, voluntary approaches to wetland conservation.* According to the agency, conserving
wetlands will depend on acquisition, cooperative agreements, education, and technical assistance. The TPWD and the
Texas General Land Office were also directed by the Texas legislature to develop a wetlands protection plan for state-owned coastal wetlands.
In 2002, Texas Parks and Wildlife Department approved a Conservation Plan
that aims protection efforts at wetlands.
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WETLAND SITES IN TEXAS
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SOURCE: TEXAS COMPTROLLER, FISCAL NOTES, MAY, 1993
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Two other state agencies have significant roles in wetlands protection: the Texas Natural
Resource Conservation Commission (TNRCC), and the Texas Water Development Board (TWDB), Among federal agencies, the Army Corps of Engineers, the Fish and Wildlife
Service, the Environmental Protection Agency, the Farm Service Agency, and USDA's Natural Resources Conservation Service share responsibility for wetlands protection and enhancement.
The Texas Parks and Wildlife Department provides technical and financial assistance to
landowners for the improvement, conservation and creation of wetlands on private lands. The Texas General Land Office has programs specifically directed to coastal wetlands. There
are also private not-for-profits helping private landowners, such as Ducks Unlimited. The Wetland Reserve Program of the 1985 Farm Bill provided financial incentives to protect and
restore wetlands on agricultural land and so, too, has the 2002 farm bill. As of September 2002, a total of 1,074,245 acres around the country of agricultural land were enrolled in
USDA's Wetland Reserve Program.* In
Texas,43,175 acres of wetlands on privately held agricultural lands had permanent easements. The easements are held by USDA's Natural Resource Conservation Service.*
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ESTIMATES OF TEXAS WETLAND ACREAGE
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WETLAND TYPE
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SHAW AND FREDINE (1956)
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DIENER (1975)
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KIER et. al. (1977)
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TPWD (1980)
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GUTHREY et. al. (1981)
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MC ADAMS et. al. (1982)
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NRCS (1994)
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Statewide
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7,021,637
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6,290,800a
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Coastal Marshes
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937,400
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1,141,400b
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473,320
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611,760
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Coastal Potholes
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89,000
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Bottomland Hardwood
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5,973,000
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Swamp
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106,880
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95,342
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Playa Lakes
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341,535
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a. Acreage does not include federal land
b. Acreage includes tidal flats as well as emergent marsh
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Source: Texas Parks & Wildlife Department, Texas Wetlands
Conservation Plan (1997), 32. S. P. Shaw and C. G. Fredine, Wetlands of the U.S.: Their Extent and Their Value to Waterfowl and Other Wildlife (Washington D.C.:
USFS, 1956). R. A. Diener, Cooperative Gulf of Mexico Estuarine Inventory and Study Texas, NOAA Technical Report (Washington D.C., NMFS, 1975). R. S. Kier and L.
F. Brun, Jr., Land Resources of Texas – A Map (Austin: University of Texas, Bureau of Economic Geology, 1997). Texas Parks & Wildlife Department, Statewide
Vegetation Mapping. Unpublished data. 1980. F. S. Guthery, Playa Assessment Study. Unpublished report on file at Texas Tech University, Lubbock, Texas. M. S.
McAdams, Proceedings, International Symposium on Tamaulipan Biotic Province, David Diskind, editor (Asutin: TPWD, 1982). Natural Resources Conservation Service,
Texas Tables: 1992 National Resources Inventory (Temple: NRCS, 1992).
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