Oceans & Coastal Resources:
A Briefing Book
Congressional Research Service Report 97-588 ENR
Redistributed as a service of the National Library for the Environment

Coastal Wetlands

Prepared by Jeffrey A. Zinn

Senior Analyst in Natural Resources Policy
Environment and Natural Resources Policy Division

Issue Definition
Background and Analysis
Status of the Issue
Continuing Concerns
Sources and References for Further Information

Issue Definition

Wetlands, areas where upland and water areas overlap to create unique environments, are concentrated in some coastal areas, especially along the south Atlantic and Gulf coasts. The numerous values that are unique to these areas have been increasingly appreciated in recent years, but at the same time, a portion of the remaining acreage is being destroyed or damaged by development and other activities. The particulars of the pressures for change vary from place to place, but the forces at work are generally the same. At issue is the effectiveness of various federal (and state) wetlands protection efforts. Some, but not all, activities are regulated through a permit program administered by the U.S. Army Corps of Engineers under §404 of the Clean Water Act. Protection advocates and development interests have debated whether coastal wetlands deserve further recognition, both as an important subset of all wetlands because of their different hydrologic and biologic properties, and because of concentrated economic gains from their modification.

Background and Analysis

The U.S. Fish and Wildlife Service estimates that coastal wetlands in the coterminous states currently cover more than 26 million acres. About 5.5 million acres of salt marsh and mangroves are on the coast and concentrated in the Southeast, while more than 20 million acres of freshwater and forested wetlands lie along rivers and estuaries that drain into the oceans. The Atlantic and Gulf coasts each have more than 10 million acres, while the Pacific coast has slightly more than one million acres.

Coastal wetlands occur in a wide variety of forms, but they all have distinctive plant assemblages because of the wetness of the soil. Many coastal wetlands are flooded daily as the tide rises and falls. The value of coastal wetlands depends on location, size, and relationships with adjacent land and water areas. Wetland values can include:

Usually wetlands provide a mix of these values; no single wetland provides all of them at the same time. Many of these values decline when wetlands are altered. For example, in coastal areas, conversion of wetlands to urban uses can increase the cost of flood damage because wetland areas typically provide natural storage and slow the release of flood waters. Alterations at some distance also can affect wetlands because they are part of larger water systems. Examples include airports in New York, Boston, and other coastal cities where not only is the airport built on filled wetlands, but the altered patterns of water flow have adversely affected other wetlands.

Wetlands have been disappearing at a rapid rate through most of this country's history. The U.S. Fish and Wildlife Service estimates that 104 million acres remain of the 220 million that were here when the country was first settled. The Service's most recent national report estimated that the rate of loss between the mid-1970s and the mid-1980s was about 290,000 acres per year. More recent studies by others indicate that the rate has continued to drop, and is currently less than 100,000 acres annually. This is a significant decline from an earlier survey, from the mid-1950s to the mid-1970s, when the loss rate averaged nearly 500,000 acres per year. No estimates are available for the coastal subset.

Coastal wetlands are probably disappearing less rapidly than all wetlands for two reasons. First, many of the conversions have been to drain these lands for agriculture; coastal wetlands, especially in salt water environments, are not attractive sites for agricultural production. Second, efforts to protect wetlands in this country focused on coastal areas initially; there is a relatively strong and lengthy tradition of federal and state efforts to protect coastal wetland areas. In a study of wetlands loss in the Mid Atlantic states between the 1950s and 1970s, the U.S. Fish and Wildlife Service concluded that coastal wetland losses were much smaller than the inland wetland losses. The major causes of coastal wetland loss were identified as urban development and encroachment by coastal waters caused by impoundments, dredging projects, and rising sea level. (By contrast, the major causes of freshwater wetlands loss were other development, agriculture, and ponds.) Coastal wetland losses are concentrated in highly developed areas, such as San Francisco and Chesapeake Bays.

Expansion of coastal waters at the expense of wetlands is a problem in many areas. The most notable, because of the shear magnitude of both the amount of loss and the reservoir of remaining wetlands that could be lost, is Louisiana. Estimates of annual wetland loss have ranged up to about 60 square miles (38,000 acres), and an historic review showed that over 680,000 acres became open water between 1956 and 1978. High loss rates are partially attributed to natural phenomena, including sea level rise and settling of the land. But in the case of Louisiana, it is also attributed to several human factors, including dredging channels through the wetlands that have disrupted water flows, and impediments upstream on the Mississippi River and its tributaries that have halted the flow of sediments and altered the rates and patterns of fresh water flows around its delta.

Status of the Issue

Wetlands have been a major issue for several years, as Congress has debated alternative proposals to amend the federal permit program under §404 of the Clean Water Act. The Clean Water Act has not been reauthorized since 1988; authorization for appropriations expired in 1994. Debate over reauthorization was not resolved by the 104th Congress, and is anticipated to continue in the 105th. Wetlands will likely be a key topic once again, as protection advocates press to strengthen section 404 while property owners and development interests seek greater flexibility.

While the debate continues, some new information has been provided to Congress. One example is a National Academy of Sciences study of wetland delineation issues, released in May, 1995. While it was released during the House debate on reauthorization, none of the ideas it presented were incorporated into the House-passed legislation.

Prior to the 104th Congress, controversy over wetlands protection had been especially intense under the Bush Administration, which had attempted to make wetland protection a major environmental initiative. It had tried to implement a general policy of no-net-loss while also satisfying environmental and developmental constituencies. Much of this debate centered on alternative proposals to change the interpretation of the wetland definition under the §404 program so that, under the first proposal, it would include additional areas, and under the second proposal, would exclude many places classified as wetlands.

The wetlands issue continued to receive attention, especially after the Clinton Administration announced its positions on several wetland topics, including continued support for the no-net-loss concept and possible revisions to implementation of §404, in August 1993. Some administrative efforts implementing these positions have attracted greater congressional attention and opposition , while others have proceeded with little apparent controversy.

Continuing Concerns

These concerns and questions are provided to stimulate further discussion of the issues noted above.

Currently, all wetlands are treated equally, but some argue that protection efforts should vary. Should wetlands protection efforts recognize classes of wetlands based on functions and values? Should coastal wetlands receive special attention because of the extreme developmental pressures or their unique biological and hydrological characteristics? Can the full diversity of coastal wetlands be recognized through a single federal program? How can state and federal wetlands protection efforts be better integrated? Should coastal wetlands be protected as part of larger systems, such as watersheds or estuaries? If so, how can such efforts be coordinated with existing wetlands programs?

Sources and References for Further Information

U.S. Congress, House Committee on Merchant Marine and Fisheries. The Administration's New Wetlands Policy. Hearings, 103rd Cong., 1st Sess. Sept.28, 1993. Washington, DC: U.S. Govt. Print. Oft, 1994. 113 p. Serial Number 103-62.

U.S. Congress, Senate Committee on Environment and Public Works, Subcommittee on Clean Water, Fisheries and Wildlife. Reauthorization of the Clean Water Act. Hearings, 103rd Cong., 1st Sess. June 16, 23; July 1, 14, 27; Aug. 4, 5; and Sept.15, 1993. Washington, DC: U.S. Govt. Print. Off., 1994. 1702 p. S.Hrg. 103-328.

U.S. Dept. of the Interior, Fish and Wildlife Service. Wetlands Losses in the United States: 1780s to 1980s. Washington, DC: 1990. 13p.

----- and U.S. Dept. of Commerce. Coastal Wetlands of the Continental United States. Washington, DC: 1992 n.p.

U.S. General Accounting Office. Wetlands Overview: Federal and State Policies, Legislation, and Programs. GAO/RCED-92-79 FS. Washington, DC: Nov. 1991. 93p.

U.S. Library of Congress, Congressional Research Service. Wetland Issues. CRS Report for Congress IB97014. [by Jeffrey Zinn.] Washington, DC: updated regularly.

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