3—
Planning and Evaluating Aquatic Ecosystem Restoration

INTRODUCTION

The fundamental goal of aquatic ecosystem restoration is to return it to a condition that resembles its natural predisturbance, state as closely as possible. Achievement of this goal entails restoration of the target ecosystem's structure and function both locally and within its broader landscape or watershed context. To measure the degree of success in achieving restoration goals, physical, chemical, and biological evaluation data are necessary to verify that an ecosystem is performing as it should.

To achieve long-term success, aquatic ecosystem restoration should address the causes and not just the symptoms of ecological disturbance. Sometimes these causes are obvious; sometimes they are subtle and far removed in space and time from the ecological damage, as in the case of Grove Lake in Pope County, Minnesota. In the 1800s, small prairie potholes were ditched and drained there in the headwaters of the Crow River (see Prairie Potholes case study, Appendix A). Runoff quantities and velocities were increased by the straightened, more efficient drainage system. This increased the movement of nutrients and sediments downstream. These materials entered Grove Lake and several downstream lakes, causing water quality problems that resulted in accelerated eutrophication and other changes in plant composition. The lakes also became progressively shallower and less attractive to wildlife. Dredging the lakes or altering the water chemistry produced temporary restoration of certain lake functions, but



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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy 3— Planning and Evaluating Aquatic Ecosystem Restoration INTRODUCTION The fundamental goal of aquatic ecosystem restoration is to return it to a condition that resembles its natural predisturbance, state as closely as possible. Achievement of this goal entails restoration of the target ecosystem's structure and function both locally and within its broader landscape or watershed context. To measure the degree of success in achieving restoration goals, physical, chemical, and biological evaluation data are necessary to verify that an ecosystem is performing as it should. To achieve long-term success, aquatic ecosystem restoration should address the causes and not just the symptoms of ecological disturbance. Sometimes these causes are obvious; sometimes they are subtle and far removed in space and time from the ecological damage, as in the case of Grove Lake in Pope County, Minnesota. In the 1800s, small prairie potholes were ditched and drained there in the headwaters of the Crow River (see Prairie Potholes case study, Appendix A). Runoff quantities and velocities were increased by the straightened, more efficient drainage system. This increased the movement of nutrients and sediments downstream. These materials entered Grove Lake and several downstream lakes, causing water quality problems that resulted in accelerated eutrophication and other changes in plant composition. The lakes also became progressively shallower and less attractive to wildlife. Dredging the lakes or altering the water chemistry produced temporary restoration of certain lake functions, but

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy once these symptom-oriented treatments had been completed, the symptoms began to reappear. Restoration of a river or other aquatic system requires replacing not only the predisturbance morphology but the hydrologic conditions as well. To accomplish this, land uses may have to be altered, vegetation may need to be reestablished, and interrelated ecosystems—tributaries or adjacent wetlands—may have to be given fundamental corrective ecological attention as well. FIGURE 3.1 Schematic representation of a restoration scenario. *Examples of state variables include river stage, water temperature, and fish species.

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy In the development of restoration strategies, restoration of an ecosystem to an approximation of its natural predisturbance condition should be pursued as the first goal. However, in some situations, this ideal may be impractical, as illustrated in Figure 3.1. The shaded area represents an ''envelope" in which the morphology and function of the ecosystem are considered to be acceptable and achievable under existing social, political, economic, and engineering constraints. The goals in this restoration scenario would be to move the ecosystem by the time the project is complete from its present state to some point within the achievable envelope. RESTORATION PROJECT PLANNING Planning a restoration project starts with specifying the project mission, goals, and objectives (Table 3.1). The goals and objectives then become the basis for the evaluation assessment criteria. The TABLE 3.1 Restoration Checklist Project Planning and Design 1. Has the problem requiring treatment been clearly understood and defined? 2. Is there a consensus on the restoration program's mission? 3. Have the goals and objectives been identified? 4. Has the restoration been planned with adequate scope and expertise? 5. Does the restoration management design have an annual or midcourse correction point in line with adaptive management procedures? 6. Are the performance indicators—the measurable biological, physical, and chemical attributes—directly and appropriately linked to the objectives? 7. Have adequate monitoring, surveillance, management, and maintenance programs been developed along with the project, so that monitoring costs and operational details are anticipated and monitoring results will be available to serve as input in improving restoration techniques used as the project matures? 8. Has an appropriate reference system (or systems) been selected from which to extract target values of performance indicators for comparison in conducting the project evaluation? 9. Have sufficient baseline data been collected over a suitable period of time on the project ecosystem to facilitate before-and-after treatment comparisons? 10. Have critical project procedures been tested on a small experimental scale in part of the project area to minimize the risks of failure? 11. Has the project been designed to make the restored ecosystem as self-sustaining as possible to minimize maintenance requirements? 12. Has thought been given to how long monitoring will have to be continued before the project can be declared effective? 13. Have risk and uncertainty been adequately considered in project planning?

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy During Restoration 1. Based on the monitoring results, are the anticipated intermediate objectives being achieved? If not, are appropriate steps being taken to correct the problem(s)? 2. Do the objectives or performance indicators need to be modified? If so, what changes may be required in the monitoring program? 3. Is the monitoring program adequate? Post-Restoration 1. To what extent were project goals and objectives achieved? 2. How similar in structure and function is the restored ecosystem to the target ecosystem? 3. To what extent is the restored ecosystem self-sustaining, and what are the maintenance requirements? 4. If all natural ecosystem functions were not restored, have critical ecosystem functions been restored? 5. If all natural components of the ecosystem were not restored, have critical components been restored? 6. How long did the project take? 7. What lessons have been learned from this effort? 8. Have those lessons been shared with interested parties to maximize the potential for technology transfer? 9. What was the final cost, in net present value terms, of the restoration project? 10. What were the ecological, economic, and social benefits realized by the project? 11. How cost-effective was the project? 12. Would another approach to restoration have produced desirable results at lower cost? project mission is the overall general purpose, such as the restoration of a particular stream and perhaps a fringe of adjoining riparian wetlands. The goals might include restoring water quality, benthic substrate, hydrology, channel stability, riverine flora and fauna, and wetland flora and fauna. Goals should be prioritized so that project designers and evaluators have a clear understanding of their relative importance. Objectives are then derived from the goals, giving, for example, the specific characteristics of water quality to be achieved, the particle size and condition of the benthic substrate, the species composition and population sizes of the various communities of aquatic biota expected, and so on. Finally, the evaluator must construct specific "performance indicators" linked to each objective. These performance indicators are specific measurable quantities that reveal

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy to what extent the objectives are being achieved. In the case of water quality, they might include indicators such as pH, amount of chlorophyll in a water sample, or Secchi disk visibility. In addition to specifying goals, objectives, and performance indicators, project managers and designers should propose a monitoring and assessment program that is appropriate in scale (areal extent), as well as in sampling frequency and intensity, to measure the performance indicators accurately and reliably, and thereby assess progress toward the project's objectives, goals, and mission. Project Schedule A realistic restoration schedule needs to be set to avoid inappropriate expenditures of effort and money. Enough time must be allowed for pre-and postproject monitoring so that the estimates of baseline and reference conditions used are representative and reliable. Monitoring must be maintained long enough for resource managers to confirm that the restoration can withstand unusual environmental events, such as floods, droughts, and frosts. In regions where environmental conditions are highly variable from year to year, the time frame will probably have to be long. For example, at least one wetland restoration project in San Francisco Bay has a 20-year monitoring requirement. Adequate financing must be provided to guarantee long-term maintenance and surveillance of the project. However, detailed 20-year monitoring and assessment programs will not be needed for every restoration project, particularly simple projects for which there is a large experience base. As restoration technology improves in reliability, selective monitoring using cost-effective indicators should become possible. Project Scale The areal extent of a restoration project is important for four reasons. First, the project area needs to be large enough to limit deleterious effects that boundary conditions may impose on interior aquatic functions. For example, a prairie slough restored too close to a highway may be stunted in its development by de-icing agents in road runoff. Second, project managers must be able to exert influence over zones in which major causes of ecological disturbance to the project are occurring, so that the disturbance can be controlled or eliminated. Third, the area needs to be large enough so that important effects of the project can be monitored for project assessment purposes. Finally, the project should be of an affordable size.

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy The restoration of a site should be considered in a regional context, and the area that will be available to reestablished wildlife communities should be considered in relation to the size and longevity of the organisms that will occupy the restoration site. Restoration of a vernal pool may be viewed in the context of its local watershed or with respect to the distribution of its main species or subspecies; however, plans for the restoration of migratory waterfowl or wading bird habitat must include continental or intercontinental considerations. In many cases, the restoration planner must review land uses adjacent to the project for potential disturbances or other effects of interactions, including hydrological connections. In developing specific plans for ecosystem reconstruction from the landscape perspective, it may be necessary to look quite far for undisturbed systems to serve as reference systems. For southern California coastal wetlands, the nearest low-disturbance reference site is 300 km south of the border in Mexico. Biogeographic information (i.e., distributional limits of species known to inhabit local, more disturbed sites) is clearly required to estimate whether the species lists and relative abundances of organisms at a distant site are appropriate for the restoration site. Knowledge of the migratory routes of birds and fish, and of dispersal patterns for invertebrate larvae and seeds, is critical in determining what scale to use in planning aquatic restorations. Ideally, an effective restoration will have a positive ecological influence beyond the immediate project site. For example, an isolated wetland may have been restored partly in the hope that migratory birds would use it. Its ability to provide the desired migratory bird habitat function, however, depends in part on processes operating on a continental scale; thus, assessment may require a much broader evaluation of waterfowl behavior and production than merely at the restoration site itself. For example, a restored wetland that fails to attract birds for a year or more need not be considered a failure if migratory patterns have shifted for reasons other than the quality of the restored habitat. The contrast between the temporal and spatial scales of existing restoration assessment practices and assessment needs as proposed in this chapter is depicted in Figure 3.2. Genetic Issues The scale of genetic variation is an important but little-known factor affecting restoration efforts. Until genetic inventories are available for species to be planted or transplanted to restoration sites, and until we understand how great the genetic variability must be in the

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy FIGURE 3.2 Time scale of the assessment. The diagram compares the usual (and very limited) protocol for assessing the "success" of a restoration site with an idealized framework, involving long-term, detailed, and large-scale evaluation. transplanted stock, it is advisable to select material from local sources by sampling broadly within those populations. Transplantation of Spartina foliosa from San Francisco Bay, where it is abundant, to San Diego Bay (more than 800 km away), where it is uncommon, may provide plant cover, but there are two risks if these populations are genetically distinct. The northern population may not tolerate the higher soil salinities that develop in some years; alternatively, a foreign population may grow better and outcompete the local ecotype. Only the use of local genotypes can preserve and maintain local biodiversity. The local range of genetic variation is also of concern. Because many of the favorite transplant species for marshes reproduce vegetatively (and are propagated vegetatively by suppliers), there is a risk that sites will be established from single clones, whose descendants may someday die en masse if a rare environmental event occurs or an unusual parasite infests the restoration site. Thus, care must be taken to specify local, diverse plant material, and suppliers must keep permanent records of the sources of their materials.

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy Human Influences It would be impractical to develop or implement a restoration program in most areas of the United States without explicitly considering the effects of humans (see Chapter 6). Consequently, project design criteria should reflect both human behavior and needs, and the biological needs of project species. For example, humans may demand that restoration work address acute water quality problems, reduce the threat of flooding, increase biodiversity, or simply create a more aesthetically pleasing landscape. In addition, humans may themselves damage the experimental ecosystem before it has a chance to develop. Adequate provision should therefore be made for project fencing or other access control, when necessary to safeguard against vandalism or depredations by domestic animals, or to provide wildlife seclusion and protection. The integration of human values and ecological performance is illustrated by the project assessment matrix shown in Figure 3.3. The unacceptable position in the lower left corner is identified by a solid black box. In this case, neither human nor ecological values are provided by the project. This position might be represented in the case of a dam constructed to provide irrigation where the stream flow was inadequate to fill the reservoir. Therefore the dam provided no agricultural benefits and destroyed wildlife habitat. The progression from the lower left corner (cell A0) to the upper right corner (cell C2) of the matrix can be represented by a project using wetlands for wastewater treatment. No ecological or human value is achieved if, when wastewater is discharged into the wetland, the wetland is destroyed and no nutrient removal occurs. However, some ecologic and human values can be achieved if the wetlands are able to survive wastewater discharge but are then converted to a low-density or a monotypic plant community. To achieve ultimate success (cell C2), the wastewater effluent would be treated to the desired standards while the wetland simultaneously supported a high density of plants and animals. This latter project might be termed restoration if wastewater flows emulated historic hydrologic conditions and if the plants, animals, and landscape adequately represented predisturbance conditions. A restoration often cannot follow a vertical path from low to high ecological values (cell A0 to C0). Some economic or social benefit often must be produced, tilting the line to the right toward C2. This need not be undesirable because ecological and human values can often be served simultaneously. Restoration failures may occur for several different kinds of reasons.

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy In the first case, restoration projects can be carelessly implemented, as when a contractor disregards engineering or horticultural specifications. Examples include installation of wetlands using nonlocal biota that may not be adapted to local soil salinity or temperature, or planting saltwater wetlands at the wrong tidal elevation. In these cases, the project might have succeeded had engineering design criteria and restoration protocols been observed. The failure is thus not a fault of ecological science or engineering knowledge but of implementation. Another kind of failure occurs when design criteria are scrupulously followed and the project designer's knowledge proves inadequate FIGURE 3.3 Project assessment matrix.

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy to produce a functional restoration design. A third class of failure occurs when objectives and criteria are not established prior to the project (Kusler and Kentula, 1989). These projects lack milestones to judge progress, and in the absence of assessment criteria for use in monitoring, it is hard to obtain early warnings that the restoration is not "on track." PURPOSE OF EVALUATION The general purpose of evaluating an aquatic ecosystem restoration project is either to determine how effective the restoration attempt was in replicating the target ecosystem or to select from among competing restoration projects the one most likely to prove effective. Evaluation of a completed restoration project (postproject evaluation) is vital to learning whether the permit requirements of a mandatory restoration project (e.g., one performed for mitigation purposes) have been achieved and is also essential for people conducting discretionary restoration projects to know how effective their efforts have been. Evaluation before the fact (preproject evaluation) can help a decision maker identify the project most likely to provide the greatest ecological benefits at the lowest cost, an especially important consideration in an era of budgetary constraints and enormous environmental challenges. Naturally, 100 percent similarity of a restored system to predisturbance conditions is impossible to achieve; even two parts of any single pristine aquatic system are never 100 percent similar in either structure or function. Therefore, perfection should not be expected in restoration, and restoration planners must recognize that restoration is an exercise in approximating prior conditions. SELECTING ASSESSMENT CRITERIA AND SYNTHESIZING DATA An evaluation of aquatic restoration must include procedures for synthesizing data to be produced by monitoring the restoration project or by analyzing the restoration proposals. The evaluation framework should define the problem, specify what data are to be collected when, and explain how the data are to be used once collected. The latter seemingly self-evident point is actually a critical issue in ecosystem evaluation. Because restoration strives to alter an existing ecosystem so that it becomes more similar to a predisturbance model, the evaluator needs to gather a comprehensive data set relating the restored system to the antecedent one in biological, physical, and chemical

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy terms. The data gathered on these diverse aspects of project performance can be extensive and conflicting, because achievements may differ greatly from one aspect of the restoration to another. (For example, a restoration may be effective in producing good water quality, but poor in reproducing some of the ecosystem's floral or faunal characteristics, or vice versa). Therefore, if a decision maker is to use the results of evaluation for a policy decision, rules may have to be established for synthesizing large quantities of observational data into a form in which comparisons between projects become possible, clear, and meaningful. Because in completely evaluating a restoration, one is in effect evaluating an entire ecosystem, a broadly representative range of assessment criteria must be used to reflect the major dimensions of the ecosystem, including its complex food webs, habitat heterogeneity, and dynamic physical, chemical, and biological processes. Thus, thorough evaluation of a restoration may become a complex, multidisciplinary process involving a great deal of data collection and necessitating that the resulting body of basically incomparable or unrelated data be reduced to manageable terms by using multiattribute decision techniques. (For a discussion of multiattribute decision techniques to compare complex restoration projects, see MacCrimmon, 1968; Raiffa, 1969; Stokey and Zeckhauser, 1978; Tecle et al., 1988; Berger, 1991). Interpretation of the results of evaluation is always facilitated by a skillfully written narrative explanation of project outcomes. Often this documentation will be all that is required, especially for relatively simple, straightforward projects. One solution to submerging the decision maker in a sea of data is to strategically select assessment criteria that suggest the presence of a host of other complex desired ecological states. For example, use of a measure such as the biomass of key indicator plants in a wetland species assemblage may provide a great deal of information about the reestablished vegetation. Use of the wetland by wading birds, waterfowl, and fish also provides "an integrated measure (i.e., [one] dependent on an array of structural features) . . . of floodplain integrity" (Toth, 1991). Assessment Criteria Assessment criteria should include both structural and functional attributes of the ecosystem, and should be based on known antecedent conditions of the target or reference ecosystem. These criteria should be established well before the assessment takes place and should be linked, as described above, to specific project objectives.

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy Assessment measurements should take into account both temporal variation and spatial heterogeneity. Thus, attributes that are patchy in time or space need widespread and long-term characterization. Multiple criteria should be employed to minimize the risk of overlooking important ecological effects, and a range of reference systems and long-term data sets should be compared with the project's attributes if possible. As noted in this chapter, performance indicators that are implicitly or explicitly derived from project objectives are the assessment criteria that are actually used in the evaluation process. However, selecting an appropriate subset of indicators from the universe of possible evaluation factors is a skill and an art—in essence, a separate decision problem that is of great importance to the feasibility, cost, and validity of the evaluation. To assist the decision maker in developing appropriate indicators, the next three sections contain annotated lists of possible structural, functional, and holistic ecological assessment criteria, adapted from Berger (1990). (Additional evaluation criteria for aquatic restoration are provided in Chapter 6 and Zedler et al., 1988; Berger, 1990, 1991; PERL, 1990; Southland, 1991.) STRUCTURAL CHARACTERISTICS The following are examples of structural characteristics: Water quality both on and off the project site, wherever affected by the restoration. Measures include dissolved oxygen, dissolved salts, dissolved toxics and other contaminants, floating or suspended matter, pH, odor, opacity, temperature profiles, and other indicators. Soil condition as revealed by soil chemistry; erodibility; permeability; organic content; soil stability; physical composition, including particle sizes and microfauna; and other factors. Geological condition as indicated by surface and subsurface rock and other strata, including aquifers (see hydrology). Hydrology, including quantity of discharge on annual, seasonal, and episodic basis; timing of discharge; surface flow processes, including velocities, turbulence, shear stress, bank/stream storage, and exchange processes; ground water flow and exchange processes; retention times; particle size distribution and quantities of bed load and suspended sediment; and sediment flux (aggradational or degradational tendencies) (Rosgen, 1988). Topography as indicated by surface contours; the relief (elevations and gradients) and configuration of site surface features; and project size and location in the watershed, including position relative

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy to similar or interdependent ecosystems. Riverine floodplain wetlands, for example, require a river to provide periodic inundation. Morphology( may be subsumed by topography) as indicated by the shape and form of the ecosystem, including subsurface features. For a lake, morphology includes shoreline circumference-to-area ratio, mean depth, and mean-depth-to-maximum-depth ratio. For rivers and streams, it includes channel patterns (braided, meandering, or straight); bank width-to-depth ratios; meander geometry (amplitude, length, radius of curvature); cross-sectional depth profiles; and riffle-to-pool ratio (river and stream descriptions). For wetlands, morphology includes inlets and outlets, channels, islands, adjacent uplands-to-wetlands ratio, fetch and exposure, and vegetation-water interspersion (Adamus et al., 1987). Flora and fauna, including density, diversity, growth rates, longevity, species integrity (presence of full complement of indigenous species found on the site prior to disturbance), productivity, stability, reproductive vigor, size-and age-class distribution, impacts on endangered species, incidence of disease, genetic defects, genetic dilution (by nonnative germ plasm), elevated body burdens of toxic substances, and evidence of biotic stress. Carrying capacity, food web support, and nutrient availability as determined for specific indicator species. Ultimately, these will be a function of nutrient availability in conjunction with other site-specific factors. Nutrient availability and nutrient flux patterns are therefore subsumed under ''carrying capacity." However, an understanding of nutrient dynamics will give the resource manager more predictive capability than simply knowing current carrying capacity. Two questions of interest are whether the ecosystem is gaining or losing nutrients, and whether the nutrient flux is comparable to that in the antecedent system. FUNCTIONAL CHARACTERISTICS The following are examples of functional characteristics: Surface and ground water storage, recharge, and supply. Floodwater and sediment retention. Transport of organisms, nutrients, and sediments. Humidification of atmosphere (by transpiration and evaporation). Oxygen production. Nutrient cycling. Biomass production, food web support, and species maintenance.

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy Provision of shelter for ecosystem users (e.g., from sun, wind, rain, or noise). Detoxification of waste and purification of water. Reduction of erosion and mass wastage. Energy flow. See Chapter 6, Tables 6.1 and 6.2, for a more complete list and discussion of functional characteristics. EMERGENT PROPERTIES The following are examples of emergent properties (i.e., those exhibited by the ecosystem as a whole): Resilience, the ability of the ecosystem to recover from perturbation Persistence, the ability of the ecosystem to undergo natural successional processes or persist in a climax sere (a stage in ecological succession), all without active human management. Persistence incorporates the notion of self-sufficiency, the ability of the ecosystem to survive as a dynamic system, evolving in a manner and at a rate regarded as normal for that type of ecosystem at its particular stage of development. To measure the persistence or degree to which reestablished biota can sustain themselves within the context of succession, measurement units may include time between needed management intervention or units of management effort required. Examples of typical postproject modifications or maintenance include grading, replanting, and controlling weeds and pests. Verisimilitude a broad, summative, characteristic of the restored ecosystem reflecting the overall similarity of the restored ecosystem to the standard of comparison, be it prior conditions of the ecosystem or of a reference system. See Chapter 6, Table 6.4, for additional emergent properties. CONCLUSIONS AND RECOMMENDATIONS The aim of restoration is to return ecosystems to a close approximation of their natural, self-sustaining, and predisturbance condition. The function of evaluating a restoration effort is to determine in a reliable scientific manner how effective a particular restoration has been, i.e., how similar the restored ecosystem is to the target ecosystem. For comprehensive preproject evaluation of prospective restoration alternatives, economic and social impacts must be considered

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy along with ecological effects, in addition to factors such as risk and social equity (the incidence of benefits and costs for different classes of people affected by the project). For dependable evaluations, assessment criteria must include both structural and functional attributes of the ecosystem. The scale of the restoration must be adequate to account for spatial heterogeneity of habitat and for interactions between the target system and its surrounding landscape. The duration of the project and its monitoring must be sufficient to encompass unusual environmental events that periodically stress the ecosystem. Assessment criteria, evaluation methodology, restoration techniques, and project implementation must all be able to stand up to the scrutiny of peer review. If, because of budgetary or other problems, a comprehensive restoration project cannot be completed, efforts should be made to conserve valuable and unique plants and animals so that they or their gene pools will be available when restoration becomes feasible. REFERENCES AND RECOMMENDED READING Adamus, P. R., E. J. Clairain, Jr., R. D. Smith, and R. E. Young. 1987. Wetland Evaluation Technique (WET). Vol. II. Methodology Operational Draft. U.S. Army Corps of Engineers Waterways Experiment Station, Vicksburg, Miss. Berger, J. J. 1190. Evaluating Ecological Protection and Restoration Projects: A Holistic Approach to the Assessment of Complex, Multi-Attribute Resource Management Problems. Ph.D. dissertation. University of California, Davis. Berger, J. J. 1991. A generic framework for evaluating complex restoration and conservation projects. Environ. Prof. 13(3):254–262. Cairns, J., Jr. 1991. The status of the theoretical and applied science of restoration ecology. Environ. Prof. 13(3):1–9. Kusler, J. A., and M.E. Kentula, eds. 1989. Executive Summary. Wetland Creation and Restoration: The Status of the Science. Vol. I. EPA 600/3–89/038A. U.S. Environmental Protection Agency, Washington, D.C. MacCrimmon, K. R. 1968. Decisionmaking Among Multiple-Attribute Alternatives: A Survey and Consolidated Approach. Memorandum RM-4823-ARPA. The Rand Corporation, Santa Monica, Calif. Pacific Estuarine Research Laboratory (PERL). 1990. A Manual for Assessing Restored and Natural Coastal Wetlands with Examples from Southern California. California Sea Grant Report No. T-CSGCP-021. La Jolla, Calif. Raiffa, H. 1969. Preferences for Multi-Attributed Alternatives. Memorandum RM-5868-DOTC/RC. Prepared for U.S. Department of Transportation, Federal Railroad Administration. Office of High Speed Ground Transportation, The Rand Corporation, Santa Monica, Calif. April. Rosgen, D. L. 1988. The conversion of a braided river pattern to meandering—A landmark restoration project. Paper presented at the California Riparian Systems Conference, September 22–24. Davis, Calif. Southland, M. T. 1991. Ecosystem Restoration Criteria: A Review and Conceptual Framework. Dynamac Corporation, Environmental Services, Rockville, Md.

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Restoration of Aquatic Ecosystems: Science, Technology, and Public Policy Stokey, E., and R. Zeckhauser. 1978. A Primer for Policy Analysis. W. W. Norton, New York. Tecle, A., M.M. Fogel, and L. Duckstein. 1988. Multicriterion analysis of forest watershed management alternatives. Water Resour. Bull. 24(6):1169–1178. Toth, L. 1991. Environmental Responses to the Kissimmee River Demonstration Project. Technical Publication 91–02. Environmental Sciences Division, Research and Evaluation Department, South Florida Water Management District, West Palm Beach, Fla. March. Water Resources Development Act of 1990. P. L. 101–640, Nov. 28, 1990, 104 Stat. 4604. Zedler, J. B., R. Langis, J. Cantilli, M. Zalejko, K. Swift, and S. Rutherford. 1988. Assessing the functions of mitigation marshes in Southern California. Pp. 323–330 in J. Kusler, S. Daly, and G. Brooks, eds., Urban Wetlands: Proceedings of the National Wetland Symposium, Oakland, California. Association of Wetland Managers, Berne, N.Y.