Restoration of Aquatic Ecosystems Science, Technology, and Public Policy (1992) / Chapter Skim
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3 Planning and Evaluating Aquatic Ecosystem Restoration
3 Planning and Evaluating Aquatic Ecosystem Restoration
Pages 55-70
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From page 55... ...
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.
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From page 56... ...
Examples of state variables include river stage, water temperature, and fish species.
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From page 57... ...
REST012ATION 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.
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From page 58... ...
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.
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From page 59... ...
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.
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From page 60... ...
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.
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From page 61... ...
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.
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From page 62... ...
, 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.
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From page 63... ...
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.
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From page 64... ...
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)
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From page 65... ...
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.
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From page 66... ...
4. 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)
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From page 67... ...
8. Carrying capacity,food web support, and nutrient availability as determined for specific indicator species.
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From page 68... ...
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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From page 69... ...
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.
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From page 70... ...
Technical Publication 91-02. Environmental Sciences Division, Research and Evaluation Department, South Florida Water Management District, West Palm Beach, Fla.
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