Restoration of Aquatic Ecosystems Science, Technology, and Public Policy (1992) / Chapter Skim
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1 Overview
Pages 14-40
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From page 14... ...
Maintenance and enhancement of economically valuable aquatic ecosystem functions-especially floodwater storage and conveyance, pollution control, ground water recharge, and fisheries and wildlife support have all too often been largely ignored in aquatic resource management. Even when management has been directed to these ends, it has often been fragmentary in its emphasis on lakes, rivers and streams, or wetlands in isolation from their regional watershed contexts despite clear hydrological and ecological linkages.
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From page 15... ...
This report describes the status and functions of surface water ecosystems; the effectiveness of aquatic restoration efforts; the technology associated with those efforts; and the kinds of research, policy, management, and institutional changes required for successful restoration. Even if a major national effort is made to restore aquatic ecosystems, their protection and management will require continued advances in point and nonpoint pollution abatement.
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From page 16... ...
evaluate restoration attempts with respect to their scientific basis, their performance over time, the technologies used, the monitoring effort, the costs, the objectives of the effort, the degree to which these objectives have been fulfilled, and why the efforts were successes or failures, while taking political and regulatory factors into consideration; 4. identify common factors of successful restoration projects and, based on this review, provide a recommended list of criteria for successful restoration that could serve as a model for future efforts to restore aquatic ecosystems; 5.
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From page 17... ...
Another subgroup concentrated on the development of a national aquatic ecosystem restoration strategy and the changes in policy and institutions necessary to begin this process. Brief case studies were prepared by the committee, NRC staff and an NRC consultant.
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From page 18... ...
Therefore, ale restorations are exercises: in approxi mation and in the reconstruction of naturalistic rather than natural assemblages of plants and animals with their physical environments. Berger, 1990 an artificial configuration bearing little resemblance to a natural form, does not constitute restoration.
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From page 19... ...
Although the functional attributes of flood control are rehabilitated, the chemical and biological characteristics or other functional values of the wetland are not. Mitigation of frequently and rapidly fluctuating water levels in a flood control reservoir may be achieved simply by altering the release schedule from the reservoir.
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From page 20... ...
of the aquatic ecosystem to maintain its natural functions and characteristics. Preservation is sometimes mistakenly linked to mitigation via the assumption that a preserved aquatic ecosystem at one location will offset or mitigate the losses of displaced aquatic functions at another.
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From page 21... ...
1 (A STATUS OF AQUATIC RESOURCES IN THE UNITED STATES This report on the status of our aquatic ecosystems must start with an assessment of the conditions of the land surface. Ninety-seven percent of this country's surface area is land; consequently, most of the water moving into and through aquatic ecosystems interacts with the surface of the land.
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From page 22... ...
The dispersive capabilities of streams and rivers were and are inadequate to handle the large amounts of runoff generated and diverted to them from uplands and former wetlands, which once acted as flood control reservoirs. In 1912, the state engineer for Illinois observed that floods on the Des Plaines River were increasing in severity and frequency (Horton, 1914~.
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From page 23... ...
hi.' :. it: .~:: ~ FIGURE 1.1 Comparison of wetland acreage in the United States in the 1780s and the 1980s.
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From page 24... ...
However, the controls also may have detrimental effects on wildlife and other functions of aquatic ecosystems, and wetlands in the littoral zone suffer from either too much or too little water. Dynamic hydrologic cycles are all but eliminated, causing the degradation of plant and animal communities.
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From page 25... ...
estimated that in 1985 a total of 338 billion gallons of water per day was used for off-stream purposes (Table 1.2~. This represented approximately 15 percent of the total resource, or 61 percent of the sustained yield.
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From page 26... ...
Relative to the sustained yield, industrial and domestic wastewaters represent about 32 percent of the water treated. Dissolved solids are added to the stream from irrigation return flows and agricultural drainage in general.
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From page 27... ...
The hydrological effects of this loss of storage are enormous. The environmental stress and altered characteristics and functions of our aquatic ecosystems caused by dispersive and extractive uses and stream modifications are reflected in the status of our fisheries, as reported by the U.S.
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From page 28... ...
TABLE 1.4 Water Quantity Limitations on Fisheries of Perennial Streams Miles Limit Affected Percenta Diversions Agricultural 105,000 15.8 Municipal 10,700 1.6 Industrial 3,290 0.5 Dams Water supply 30,800 4.6 Flood control 26,900 4.0 Power 24,800 3.7 NOTE: Streams surveyed in 1982. aPercent of the 666,000 miles surveyed.
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From page 29... ...
Approximately Tree quarters of Me streams would support only a low-qual~ty sport fishery. TABLE 1.6 Level of Aquatic Sport Species Supported by Fisheries of Perennial Streams Surveyed in 1977 and 1982 1977 Class Level Supporteda 1982 Miles Percent Miles Percent O No species 29,000 4 29,000 4 1 Nonsport species 48,0C)
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From page 30... ...
and if the nation restored 59 million acres of wetlands in the long term, only 36.4 percent of the flood-prone areas would have to be given over to wetland restoration. The restoration could take place in littoral zones around lakes and reservoirs and along the floodplain, creating circular greenways and along the floodplain creating green corridors.
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From page 31... ...
If 2,000 river and stream segments are protected and revitalized as the commission recommended, the 59 million acres of restored wetland could be distributed along these corridors. Given that the average river segment length is 200 miles, the total length of restored river corridors would be 400,000 miles.
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From page 32... ...
indicates that about 2.6 million acres of lakes are impaired (relative to suitability for intended uses) , and this most likely is a significant underestimate of the acreage that is ecologically degraded and potentially restorable.
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From page 33... ...
More than half of the nation's rivers have fish communities adversely affected by turbidity, high temperature, toxins, and low levels of dissolved oxygen. Almost 40 percent of perennial streams in the United States are affected by low flows, and 41 percent by siltation, bank erosion, and channelization (Council on Environmental Quality, 1989~.
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From page 34... ...
streams and rivers, along with continued pollution controls, is essential. Conditions of Wetlands Wetlands provide essential functions, including flood control, soil and nutrient retention, and wildlife habitat.
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From page 35... ...
Detailed national studies should be conducted of wetlands and of each major aquatic resource type to set national goals for achieving net gains in all aquatic resources through resource restoration. NEED FOR NATIONAL AQUATIC ECOSYSTEM RESTORATION This report presents major elements of an agenda for restoration of aquatic resources.
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From page 36... ...
Numerous restoration projects at all levels of government and by the private sector are significant and promising, but unfortunately, the vast majority are small in scale and uncoordinated on a regional or a national basis. Much more restoration of aquatic ecosystems is needed to slow and reduce the loss of national aquatic resources, ecosystem services, and wildlife.
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From page 37... ...
To withstand the possible compound stresses from increasing population, and increased demands for aquatic ecosystem services, prudence requires that the nation adopt a national aquatic ecosystem restoration agenda. REFERENCES AND RECOMMENDED READING Abrahamson, D
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From page 38... ...
Madison, Wis. Federal Aid in Wildlife Restoration Act.
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From page 39... ...
National Wetlands Policy Forum. The Conservation Foundation, Washington, D.C.
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From page 40... ...
USGS Water Supply Paper 2294. Reston, Virginia Wilson, E
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