1、API PUBLr304 71 0732270 0528298 952 m Evaluation of Restoration Alternatives for Natural Resources Injured by Oil Spills HEALTH AND ENVIRONMENTAL AFFAIRS DEPARTMENT API PUBLICATION NUMBER 304 AUGUST 1991 Amerkan Petraleum Institute 1220 L Street. Northwest 41 Washington, D.C. 20005 API PUBL*304 91 W
2、 0732290 0528299 699 = Evaluation of Restoration Alternatives for Natural Resources Injured by Oil Spills Health and Environmental Sciences Department PUBLICATION NUMBER 304 AUGUST 1991 PREPARED UNDER CONTRACT BY: PIETER N. BOOTH D. SCOTT BECKER ROBERT A. PASTOROK JENNIFER R. SAMPSON WENDY J. GRAHAM
3、 PTI ENVIRONMENTAL SERVICE 15375 SE 30TH PLACE, SUITE 250 BELLEVUE, WA 98007 API PUBLX304 71 = O732290 0528300 330 FOREWORD API PUBLICATIONS NECESSARILY ADDRESS PROBLEMS OF A GENERAL NATURE. WITH RESPECT TO PARTICULAR CIRCUMSTANCES, LOCAL, STATE AND FEDERAL LAWS AND REGULATIONS SHOULD BE REVIEWED. A
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6、ENT OF LEERS PATENT. API PUBL*3OY 91 0732290 05230L 277 = Table of Contents Lit of Figures vii List of Tables ix Executive Summary xi 1 . Introduction 1 Objectives 1 Regulatory Background and Definitions 2 Report Scope and Organization . 5 2 . Conceptual Approach 7 Oil Spill Impact and Recovery 7 Ma
7、rginal Economic Analysis . 9 Estimation of Natural Resource Damages . 9 Balancing Restoration Costs and Resource Damages: The Concept of Economic Efficiency . 10 Determination of Economic Efficiency . 11 3 . Overview of Selected Oil Spill Case Histories 17 Case Histories of Oil Spills in Marine Habi
8、tats 17 Case Histories of Oil Spills in River and Stream Habitats 18 4 . Naturai Recovery 21 Definition of Natural Recovery 21 Evaluation of Natural Recovery . 23 Measures of Environmental Recovery . 26 Habitat Recovery 26 Biological Recovery 26 Resource Services Recovery 28 Factors Affecting Recove
9、ry Potential 30 Factors Related to Oil Spill Characteristics 31 Factors Related to Habitat Characteristics 32 Natural Recovery Rates . 34 . iii API PUBL*304 91, 0732290 0528302 LO3 5 . Technical Feasibility and Physical Practicability of Restoration 39 Available Restoration Techniques . 40 Habitat C
10、haracteristics that Limit Restoration 41 Vegetated Habitats 41 Exposed Rocky Shores and Beaches . 41 Sheltered Rocky Shores and Beaches 41 River and Stream Habitats . 41 Special Use Habitais., 42 Oil Characteristics that Limit Restoration . 42 Classification of Techniques . 43 6 . Impacts of Restora
11、tion Techniques 45 Seagrass Beds . 46 Kelp 49 Salt Marshes 50 Mangrove Forests 52 Dispersants . 53 Beach Cleaning 54 Sediment Removal 55 Sheltered Rocky Shores and Beaches . 56 Dispersants . 56 Flushing 57 Sediment Agitation . 57 Exposed Rocky Shores and Beaches 53 Enhanced Biodegradation 57 River a
12、nd Stream Habitats 57 Special Use Habitats . 59 Classification of Techniques . 60 7 . Evaluation of Natural Recovery and Restoration Tradeoffs 63 Application of the Conceptual Approach 63 Compounding and Discounting . 63 Development of Scenarios . 64 Illustration of Economic Efficiency 66 iv API PUB
13、LW304 71 0732270 0528303 04T W Table of Contents Scenario 1: Sheltered ShorelineSoft-Bottom Habitat . 67 Key Attributes . 67 Comparison of Lost Use Damages to Restoration Costs . 70 Scenario 2: Exposed Rocky Shoreline Habitat . 72 Comparison of Lost Use Damages to Restoration Costs . 75 Key Attribut
14、es . 77 Comparison of Lost Use Damages to Restoration Cost 80 Key Attributes . 72 Scenario 3: Sensitive Vegetated Habitat-Salt Marsh 76 Scenario 4: Low-Energy River and Stream Habitat . 83 Key Attributes . 83 Scenario 5: High-Energy River and Stream Habitat 90 Key Attributes . 90 Comparison of Lost
15、Use Damages to Restoration Cost 92 Sensitivity Analysis 94 Other Damage-Related Attributes 95 Incident-Related Attributes 96 Timing of the Accrual of Costs and Damages . 97 8 . Conclusions 99 Case History Data . 99 Natural Recovery 99 Technical Feasibility and Physical Practicability of Restoration
16、100 Impacts of Restoration Techniques . 100 Evaluation of Natural Recovery and Restoration Tradeoffs 101 9 . References 103 APPENDIX A Restoration Techniques APPENDIX B APPENDIX C Comparison of Lost Use Damages to Restoration Cost 87 Nonuse Values and the Availability of Substitutes 95 Habitat Const
17、raints on Feasibility and Practicability of Restoration Ecological Impacts of Restoration Techniques API PUBL+304 91 0732290 0528304 T8b = Vi API PUBL*304 91 m 0732290 0528305 912 m List of Figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. F
18、igure 11. Figure 12. Conceptual model of spill impacts and recovery Determination of economic efficiency Annual natural resource damages and restoration costs under a scenario of natural recovery and two restoration alternatives (Plan A and Plan B) Estimated biological natural recovery times for var
19、ious kinds of habitats Hypothetical restoration costs for Scenario 1 Hypothetical damages from lost use of areas for clamming and fishing, swimming and sunbathing, and bird-watching for Scenario 1 Hypothetical restoration costs for Scenario 3 Hypothetical damages from lost use of areas for clamming
20、and fishing, hunting, bird-watching, and other recreation for Scenario 3 Hypothetical restoration costs for Scenario 4 Hypothetical damages from lost use of areas for fishing, hunting, bird-watching, and other recreation for Scenario 4 Hypothetical restoration costs for Scenario 5 Hypothetical damag
21、es from lost use of areas for fishing, hunting and trapping, and other recreation for Scenario 5 8 12 12 34 69 71 80 81 86 88 92 92 API PUBL*304 91 m 0732290 0528306 859 m viii API PUBL*304 91 = 0732290 0528307 795 W List of Tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table
22、 8. Table 9. Table 10. Table 1 1. Table 12. Table 13. Table 14. Table 15. Table 16. Table 17. Table 18. Determination of net resource value Comparison of restoration and residual damages under four scenarios Comparison of cost of natural recovery vs. restoration under three scenarios Summary of sele
23、cted oil spills in marine environments Summary of selected oil spills in river and stream environments Factors that affect the potential for natural recovery from an oil spill Shoreline restoration techniques Technical feasibility of restoration techniques Summary of potential low-impact restoration
24、 techniques Sheltered shoreline case studies and Scenario 1 attributes Annual hypothetical restoration costs and lost-use damages for a Scenario 1 spill Exposed rocky shoreline case studies and Scenario 2 attributes Annual hypothetical restoration costs and lost-use damages for a Scenario 2 spill Se
25、nsitive vegeated shoreline (salt marsh) case studies and Scenario 3 attributes Annual hypothetical restoration costs and lost-use damages for a Scenario 3 spill Lowenergy river and stream case studies and Scenario 4 attributes Annual hypothetid restoration costs and lost-use damages for a Scenario 4
26、 spiil Annual hypothetical restoration costs and lost-use damages for a Scenario 5 spiil 10 11 13 18 19 30 40 44 61 68 70 73 76 78 82 84 89 94 ix API PUBL8304 91 0732290 0528308 621 X API PUBLU304 91 H 0732290 0528309 568 = Executive Summary The appropriateness of a habitat restoration alternative f
27、oilowing an oil spill depends on a variety of factors, including 1) the predicted rate of natural ecological recovery without restoration, 2) the actual effectiveness of the restoration alternative for enhancing the natural recovery rate, and 3) the cost of implementing restoration actions relative
28、to the natural resource damages from the oil spill. This report builds upon previous work in the field of oil spill impact assessment and habitat restoration to assess the technical feasibility and practicability of proactive restoration following oil spills and presents an approach for evaluating t
29、radeoffs between natural recovery and active restoration. The following major tasks were completed as part of this study: Evaluation of measures of natural recovery, factors affecting natural recovery, and recovery rates in selected aquatic ecosystems after oil spills Evaluation of technical feasibi
30、lity, practicability, and ecological impacts of restoration techniques Evaluation of natural resource damages relative to the costs of restoration under scenarios of low-intensity restoration, high-intensity restoration, and natural re- covery (no active restoration). Scenarios used to evaluate the
31、tradeoffs between natural recovery and restoration were based on selected case studies. The scenarios were developed to represent a broad spectrum of possible oil spills. They also represent several of the historiai oil spill cases with the largest body of knowledge regarding environmental impacts,
32、resto- ration, and natural recovery. Natural Recovery Full recovery of an ecosystem may be achieved by natural processes without restoration efforts by humans. The rate at which natural recovery occurs will be a function of habitat type (e.g., rocky shoreline vs. salt marsh), amount and type of petr
33、oleum (e.g., crude xi API PUBL*304 93 0732290 0528330 28T M Executive Summary oil vs. refined products), geographic location (e.g., arctic vs. tropics), and other location-specific factors (e.g., sediment grain size, tidal flushing, exposure). Assessment of natural recovery may include measures of p
34、hysical- chemical habitat recovery (e.g. ? concentration of petroleum hydro- carbon residues), biological community recovery (e.g . , species abundances or community indices), and resource services recovery (Le, recovery of environmental attributes that are vaiued by hu- mans). From a natural resour
35、ce damages perspective, resource services recovery is often most important. Physical-chemical re- covery can generally be expected to occur more rapidly than biological recovery (largely because biological recovery is often dependent on habitat recovery). Estimates of biological recovery times have
36、been derived in the scientific literature on oil spiiis and range from approximately 2-3 years for rivers, streams, and exposed marine shores to approximately 10-20 years for mangrove forests. Recovery of resource services may occur more slowly or more rapidly than biological recovery, depending on
37、the relation- ships between the services and the elements of the environment (e.g., habitats and species) that are affected by an oil spill. Technical Feasibility and Physical Practicability of Restoration For the purposes of this study, the term restoration includes oil spa cleanup techniques used
38、before or in support of activities that are intended to directly enhance animal or plant populations. Techni- cally feasible activities that can be applied as restoration techniques include chemical dispersal, sorption, flushing, substrate removal, manual oil removal, vacuum pumping of oil, enhanced
39、 biodegra- dation of oil, wildlife rehabilitation, introduction of plants or animals, and physical habitat enhancement. Natural recovery is a technically feasible option for all spill circumstances, although recovery times may be long for iarge spills in sheltered habitats such as marshes and mangro
40、ve swamps. Technical and physical factors may need to be evaluated on a case-bycase basis to determine when a particular restoration option is practicable. xi i API PUBL*304 91 = 0732290 052831L 116 = Executive Summary Impacts of Restoration Techniques Oil spill case histories have shown that restor
41、ation efforts may fii and result in delayed recovery because of adverse impacts mainly related to physical effects on habitat structure, redistribution of spilled oil or other contaminants present before the spill, and alteration of biological assemblages. However, there are several low-impact resto
42、ration techniques that may be applicable to a variety of habitats. If restoration activities are implemented properly, low-impact techniques include sorption, flushing, vacuum pump- ing, enhanced biodegradation, wildlife rehabilitation, introduction of plants or animals, and physical habitat enhance
43、ment. Evaluation of Natural Recovery and Restoration Tradeoffs Natural recovery processes are generally the dominant factors controlling the recovery of oiled habitats regardless of restoration efforts. Hypothetical restoration costs and natural resource dam- ages (Le., lost resource value) were dev
44、eloped for oil spill scenarios in the following habitats: Soft-bottom Exposed rocky shoreline Saltmarsh Low-energy river or stream High-energy river or stream. Hypothetical scenarios were developed because existing data from case histories were inadequate for evaluating restoration costs and natural
45、 resource damages. When the objective of a spiil response (including restoration com- ponents) is to minimize the total cost to society of a spill, and the total cost of a spill is quantified based on the sum of restoration costs and natural resource damages, natural recovery is typically the prefer
46、red option for marine habitats and low-energy river and stream habitats based on hypothetical scenarios. Restoration is favored in the highenergy river and stream habitat scenario primar- ily because of the assumed effectiveness of sediment agitation as the restoration action. in most oil spill case
47、s with low natural resource xiii API PUBL*30Lt 91 W 0732290 0528312 052 W Executive Summary values, it is likely that active restoration will not be economically efficient. In general, available restoration techniques are not very effective for enhancing natural recovery. Moreover, human interventio
48、n to clean habitats or restore key species has sometimes rearded recov- ery, especially in sedimentary habitats or sensitive vegetated habi- tats where oil may be inadvertently mixed into sediments and organisms may be injured by foot traffk and heavy machinery. In these cases, restoration activitie
49、s may cause more severe impacts than those caused by the oil spill alone. xiv API PUBL*3OLi 9L 0732290 0528333 T99 I Introduction Most ecological systems have the ability to recover naturally from perturbations such as oil spills (e.g., Neff 1987; Baker et ai. 1990). However, in certain circumstances active restoration of habitats following a spill may enhance the rate of natural recovery. The appropriateness of habitat restoration following an oil spill depends on the predicted rate of ecological recovery without restoration, the effectiveness of restoration techniques for enha
