Economic Effects of Multiple Stresses

EPA Grant Number: R825433C060
Subproject: this is subproject number 060 , established and managed by the Center Director under grant R825433
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: EERC - Center for Ecological Health Research (Cal Davis)
Center Director: Rolston, Dennis E.
Title: Economic Effects of Multiple Stresses
Investigators: Wilen, James
Institution: University of California - Davis
EPA Project Officer: Packard, Benjamin H
Project Period: June 30, 1995 through June 30, 1998
RFA: Exploratory Environmental Research Centers (1992) RFA Text |  Recipients Lists
Research Category: Center for Ecological Health Research , Targeted Research


Ecosystems with multiple stresses typically generate effects on many endpoints. Managers face the problem of evaluating the importance of the cumulative impacts on multiple endpoints from the multiple stresses and then tracing back through the complex chains of causation to make decisions about which stresses are most important to reduce, given a valuation of the impacts on end-points. This project seeks to focuses on the end-points while examining economic effects of multiple stresses on the environment. These are generally of most immediate concern to managers and policy makers, while technical staff and scientists often focus on the stressors and the ecosystem processes they affect. For optimal environmental decision-making technical staff and scientists should be substantially influenced by the public's valuation of endpoints in the design of investigations leading to remediation.


The method being used to measure loss in recreation demand at Clear Lake due to water quality problems is the contingent valuation method, a survey technique which attempts to measure consumer surplus of an environmental amenity by asking respondents how much they would be willing to pay for provision of an amenity. In this case, the hypothesized amenities were: (i) an improvement in water quality, such that there would be fewer algal blooms and (ii) lower mercury concentration, so that consuming fish caught in Clear Lake would be safe.

Investigators visited the Clear Lake area on five separate weekends during the summer of 1995 in order to distribute contingent valuation surveys to Clear Lake visitors. Over 500 surveys were given out, and 302 were returned. Of those returned, 140 were usable. The remainder of those returned were either (a) pretest observations which were used to develop a more efficient survey design, (b) missing vital information, or were considered "protest" responses, in which the respondent failed to seriously consider the question of how much he or she was willing to pay for water quality improvement. Although the data collected was cleaned and analyzed and was generally of good quality, robust estimates with reasonable confidence intervals require a much larger data set. Preliminary results suggest that mercury contamination and algal blooms are considered roughly equally important problems by lake visitors.

Expected Results:

Investigators expect that additional data collection will be necessary because variation in water quality at the time of visitation is lacking. They hypothesize a relationship between a visitor's willingness to pay and the water quality at the time of visitation. Fortunately for the Clear Lake area but unfortunately for our research, the summer of 1995 was an unusually good one in terms of algal blooms, denying the opportunity to test our hypothesis.

A second part of this study will determine, in addition to dollars lost in reduced recreation demand, how much water quality problems have resulted in suppressed property values. Property value data for Lake County is dispersed and not easily accessible, and considerable time and expense is necessary to collect it. Time series data over the past 23 years on blue-green algae biomass and other water quality indices in the three different arms of Clear Lake has been collected by Center researchers. This data will be used as one or more of the explanatory variables in an hedonic regression of single-family residential property values. Property value data compiled for residential property transactions is available in computerized form for the years 1990 to the present.

Supplemental Keywords:

Aquatic ecosystem, California, Clear Lake, algal blooms, mercury, environmental economics, multiple stresses, contingent valuation, willingness to pay, environmental policy, recreational water quality., RFA, Economic, Social, & Behavioral Science Research Program, Scientific Discipline, Toxics, Geographic Area, Waste, Water, Ecosystem Protection/Environmental Exposure & Risk, mercury transport, Environmental Chemistry, Ecosystem/Assessment/Indicators, Ecosystem Protection, Geochemistry, HAPS, Restoration, Fate & Transport, Microbiology, Ecological Effects - Environmental Exposure & Risk, Environmental Microbiology, algal blooms, Biochemistry, decision-making, Aquatic Ecosystem Restoration, Engineering, Geology, West Coast, 33/50, Environmental Engineering, Economics & Decision Making, Ecological Indicators, contingent valuation, ecosystem valuation, valuation, stressors, mercury loading, property values, valuing environmental quality, Clear Lake, Sulphur Bank Mercury Mine, mining, mercury & mercury compounds, Mercury Compounds, public values, recreational demand, transport

Progress and Final Reports:

  • 1995
  • 1996 Progress Report
  • Final

  • Main Center Abstract and Reports:

    R825433    EERC - Center for Ecological Health Research (Cal Davis)

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R825433C001 Potential for Long-Term Degradation of Wetland Water Quality Due to Natural Discharge of Polluted Groundwater
    R825433C002 Sacramento River Watershed
    R825433C003 Endocrine Disruption in Fish and Birds
    R825433C004 Biomarkers of Exposure and Deleterious Effect: A Laboratory and Field Investigation
    R825433C005 Fish Developmental Toxicity/Recruitment
    R825433C006 Resolving Multiple Stressors by Biochemical Indicator Patterns and their Linkages to Adverse Effects on Benthic Invertebrate Patterns
    R825433C007 Environmental Chemistry of Bioavailability in Sediments and Water Column
    R825433C008 Reproduction of Birds and mammals in a terrestrial-aquatic interface
    R825433C009 Modeling Ecosystems Under Combined Stress
    R825433C010 Mercury Uptake by Fish
    R825433C011 Clear Lake Watershed
    R825433C012 The Role of Fishes as Transporters of Mercury
    R825433C013 Wetlands Restoration
    R825433C014 Wildlife Bioaccumulation and Effects
    R825433C015 Microbiology of Mercury Methylation in Sediments
    R825433C016 Hg and Fe Biogeochemistry
    R825433C017 Water Motions and Material Transport
    R825433C018 Economic Impacts of Multiple Stresses
    R825433C019 The History of Anthropogenic Effects
    R825433C020 Wetland Restoration
    R825433C021 Sierra Nevada Watershed Project
    R825433C022 Regional Transport of Air Pollutants and Exposure of Sierra Nevada Forests to Ozone
    R825433C023 Biomarkers of Ozone Damage to Sierra Nevada Vegetation
    R825433C024 Effects of Air Pollution on Water Quality: Emission of MTBE and Other Pollutants From Motorized Watercraft
    R825433C025 Regional Movement of Toxics
    R825433C026 Effect of Photochemical Reactions in Fog Drops and Aerosol Particles on the Fate of Atmospheric Chemicals in the Central Valley
    R825433C027 Source Load Modeling for Sediment in Mountainous Watersheds
    R825433C028 Stress of Increased Sediment Loading on Lake and Stream Function
    R825433C029 Watershed Response to Natural and Anthropogenic Stress: Lake Tahoe Nutrient Budget
    R825433C030 Mercury Distribution and Cycling in Sierra Nevada Waterbodies
    R825433C031 Pre-contact Forest Structure
    R825433C032 Identification and distribution of pest complexes in relation to late seral/old growth forest structure in the Lake Tahoe watershed
    R825433C033 Subalpine Marsh Plant Communities as Early Indicators of Ecosystem Stress
    R825433C034 Regional Hydrogeology and Contaminant Transport in a Sierra Nevada Ecosystem
    R825433C035 Border Rivers Watershed
    R825433C036 Toxicity Studies
    R825433C037 Watershed Assessment
    R825433C038 Microbiological Processes in Sediments
    R825433C039 Analytical and Biomarkers Core
    R825433C040 Organic Analysis
    R825433C041 Inorganic Analysis
    R825433C042 Immunoassay and Serum Markers
    R825433C043 Sensitive Biomarkers to Detect Biochemical Changes Indicating Multiple Stresses Including Chemically Induced Stresses
    R825433C044 Molecular, Cellular and Animal Biomarkers of Exposure and Effect
    R825433C045 Microbial Community Assays
    R825433C046 Cumulative and Integrative Biochemical Indicators
    R825433C047 Mercury and Iron Biogeochemistry
    R825433C048 Transport and Fate Core
    R825433C049 Role of Hydrogeologic Processes in Alpine Ecosystem Health
    R825433C050 Regional Hydrologic Modeling With Emphasis on Watershed-Scale Environmental Stresses
    R825433C051 Development of Pollutant Fate and Transport Models for Use in Terrestrial Ecosystem Exposure Assessment
    R825433C052 Pesticide Transport in Subsurface and Surface Water Systems
    R825433C053 Currents in Clear Lake
    R825433C054 Data Integration and Decision Support Core
    R825433C055 Spatial Patterns and Biodiversity
    R825433C056 Modeling Transport in Aquatic Systems
    R825433C057 Spatial and Temporal Trends in Water Quality
    R825433C058 Time Series Analysis and Modeling Ecological Risk
    R825433C059 WWW/Outreach
    R825433C060 Economic Effects of Multiple Stresses
    R825433C061 Effects of Nutrients on Algal Growth
    R825433C062 Nutrient Loading
    R825433C063 Subalpine Wetlands as Early Indicators of Ecosystem Stress
    R825433C064 Chlorinated Hydrocarbons
    R825433C065 Sierra Ozone Studies
    R825433C066 Assessment of Multiple Stresses on Soil Microbial Communities
    R825433C067 Terrestrial - Agriculture
    R825433C069 Molecular Epidemiology Core
    R825433C070 Serum Markers of Environmental Stress
    R825433C071 Development of Sensitive Biomarkers Based on Chemically Induced Changes in Expressions of Oncogenes
    R825433C072 Molecular Monitoring of Microbial Populations
    R825433C073 Aquatic - Rivers and Estuaries
    R825433C074 Border Rivers - Toxicity Studies