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Final Report: Modeling Ecosystems Under Combined Stress
EPA Grant Number: R825433C009Subproject: this is subproject number 009 , 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: Modeling Ecosystems Under Combined Stress
Investigators: Orlob, Gerald
Institution: University of California - Davis
EPA Project Officer: Levinson, Barbara
Project Period: October 1, 1996 through September 30, 2000
RFA: Exploratory Environmental Research Centers (1992)
Research Category: Center for Ecological Health Research , Targeted Research
Description:
Objective:The objective of this research project was to refine and apply existing mathematical models to evaluate hydrodynamic, water quality, and ecological responses of the Sacramento River/Delta system to alternative management strategies. We also wanted to provide information to guide research and complement other Center studies on fate and transport of toxicants, algal and other food web productivity, and fisheries biology.
Summary/Accomplishments (Outputs/Outcomes):These mathematical models are the primary tools for assessing the impacts of changed management strategies in the delta habitat, as measured by changes in flows, water levels, and water quality attributes. These changes result from specific alterations in the physical configuration of the water conveyance system and/or changes in the modes of operation identified with future strategies for water development in the delta and beyond.
We applied these models to simulate hydrodynamic, water quality, and ecological changes in the Sacramento River-Bay-Delta system that may be expected under proposed CALFED management scenarios. CALFED is a cooperative interagency program that seeks to develop and implement innovative and practical physical and/or operational alternatives for the management of fish and wildlife, water supply, flood control, and water quality in the bay/delta system. We tested the models' capability to simulate system behavior by calibration using historic data on flows, water quality, and behavior of juvenile salmon, a species potentially at risk in future development of water transfer schemes.
Our results support the potential of these mathematical tools to assess the consequences of possible management alternatives proposed by CALFED. Modeling of these alternatives, although limited in scope in this research project, indicated significant impacts of structural and operational modifications on delta flows, circulation patterns, and salinity distributions within the delta channels. Flow magnitudes increased in both north and south delta regions where channel enlargements were proposed. Although flows were increased in locations where channels were enlarged, velocity changes were minimal.
We examined two scenarios with regard to water quality: (1) a base case with withdrawals under existing conditions at Clifton Court Forebay; and (2) an operational case involving withdrawal into the Isolated Facility at Hood (a location along the Sacramento River, north of the delta). The results of the modeling simulations indicated that utilizing multiple withdrawals can improve salinity intrusion control, especially in dry and critical years. A facility such as the isolated canal was found to be only marginally beneficial in regulating water quality under either normal or wet hydrological conditions.
The impacts of proposed CALFED alternatives on juvenile winter-run Chinook salmon were assessed using a suite of models, including the newly developed SAMTRK. For all of the major alternatives, simulation results indicated that the numbers of juvenile salmon would be expected to decrease, especially in the vicinity of diversion locations. For scenarios involving pumping or channel modification to increase flow through the delta, the models indicated an increased likelihood of losses of juvenile salmon because of entrainment in diverted flows.
The results from simulations with diversions through the Isolated Facility indicate that adverse impacts correlate with the efficacy of measures to prevent losses because of entrainments (i.e., screening) and with the magnitude of diversions. Before analysis of the simulation results, it was believed that an isolated diversion facility might decrease overall salmon losses because the decrease through delta flows would not divert as many juvenile salmon into the southern delta. Although simulation results did indicate that losses of juveniles in the southern delta would decrease for the case of diversion through the Isolated Facility at Hood, the overall salmon loss actually increased because of very large losses at the Isolated Facility intake. The proposed canal intake at Hood is aligned with the main stem of the river along which all downstream migrants must pass, whereas only a limited number of salmon pass by each agricultural diversion location in the delta. The efficiency of screening facilities and their influence on juvenile survival is suggested as a primary target for future investigation using tools such as the several mathematical models that were developed in this research project.
The following activities were accomplished:
• We adapted, developed, and applied a suite of mechanistic mathematical models to provide needed insight concerning the effects of specific options for management of the Sacramento-Bay-Delta system on hydrodynamics, water quality, and ecosystem behavior. The models developed in this research provide unique tools for the assessment of the impacts of proposed management alternatives. Such tools could be utilized by federal, state, and local agencies, as well as researchers and others charged with the management and protection of water resources and aquatic ecosystems.
• We developed a new simulation model, SAMTRK, which employed a unique particle-tracking algorithm that describes the transport of individual eggs/larvae and small juvenile life stages of salmon, or groups of salmon, through the Sacramento River/Delta system. This model will be useful to other researchers investigating environmental impacts on salmon in the delta.
• We compared simulation results for selected scenarios to actual field observations to ensure that the physical models provide credible representations of the dynamic responses of the modeled environments. This validated the use of the model for future applications.
• The model results indicated that the proposed CALFED alternatives for structural and operational modifications resulted in significant impacts on delta flows, circulation patterns, and salinity distributions within the delta channels. This information should alert managers to the consequences of their alternative management strategies.
• The impacts of the various scenarios on water quality were found to be most prominent in the Isolated Facility scenario. This information could be used by managers of resources that are sensitive to water quality such as drinking water supply, agricultural diversions, and sensitive aquatic species.
• The simulation results indicated that multiple withdrawal capability is important for salinity intrusion control, especially in dry and critical years. On the other hand, a diversion canal such as the Isolated Facility was found to be only marginally effective in regulating water quality under either normal or wet hydrological conditions. This information should have implications for CALFED's environmental management decisions.
• For all of the major alternative strategies modeled, the numbers of juvenile winter-run Chinook salmon decreased, primarily because of increased losses at diversion locations. CALFED should use this information when planning future management strategies.
• Although the simulation results indicated that losses of juveniles in the south delta would decrease for the case of diversion through the Isolated Facility at Hood, the overall salmon loss actually increased because of very large losses at the intake; losses that might be mitigated by screening. Again, CALFED and other management agencies should keep our findings in mind.
• The losses of juvenile winter-run Chinook salmon at diversion locations were very sensitive to screening efficiency. This indicates that the screen design and orientation are important topics for future evaluations by investigators.
Supplemental Keywords:ecosystem, ecosystem protection, environmental exposure and risk, geographic area, international cooperation, water, terrestrial ecosystems, aquatic ecosystem, aquatic ecosystem restoration, aquatic ecosystems and estuarine research, biochemistry, ecological effects, ecological indicators, ecological monitoring, ecology and ecosystems, environmental chemistry, restoration, state, water and watershed, watershed, watershed development, watershed land use, watershed management, watershed modeling, watershed restoration, watershed sustainability, agricultural watershed, exploratory research environmental biology, California, CA, Clear Lake, Lake Tahoe, anthropogenic effects, aquatic habitat, biogeochemical cycling, ecological assessment, ecology assessment models, ecosystem monitoring, ecosystem response, ecosystem stress, environmental stress, environmental stress indicators, fish habitat, hydrologic modeling, hydrology, integrated watershed model, lake ecosystems, lakes, land use, nutrient dynamics, nutrient flux, water management options, water quality, wetlands. , Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, RFA, Ecosystem/Assessment/Indicators, Biology, exploratory research environmental biology, Ecology, Aquatic Ecosystems & Estuarine Research, Ecological Risk Assessment, Aquatic Ecosystem, Ecological Indicators, Biochemistry, Ecological Effects - Environmental Exposure & Risk, Ecosystem Protection, Ecology and Ecosystems, ecosystem response , riverine ecosystems, modeling biological effects, modeling chemical effects, river systems, chinook salmon, combined stresses, riverine ecosystems , Sacramento River, aquatic ecosystems, environmental stress, multiple pollutants, ecosystem, modeling, rivers, ecosystem stress, ecosystem response, multiple stressors
Relevant Websites:
Progress and Final Reports:
2000 Progress Report
Original Abstract
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