Final Report: Time Series Analysis and Modeling Ecological Risk

EPA Grant Number: R825433C058
Subproject: this is subproject number 058 , 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: Time Series Analysis and Modeling Ecological Risk
Investigators: Botsford, Louis , Jassby, Alan D. , Quinn, James
Institution: University of California - Davis
EPA Project Officer: Hahn, Intaek
Project Period: October 1, 1996 through September 30, 2000
RFA: Exploratory Environmental Research Centers (1992) RFA Text |  Recipients Lists
Research Category: Center for Ecological Health Research , Targeted Research


Predicting the effects of multiple stresses on biological endpoints, particularly populations of sensitive species, in a complex, spatially and temporally varying environment, challenges both the best available parameter estimation techniques and current risk assessment models. Models of risks to individual fish and wildlife populations in wide use at the beginning of the project treated temporal variation, spatial variability, or variability with age alone. However, models successfully predicting extinction risks when vital rates vary over both time and space, particularly for organisms such as fish that swim or are transported among multiple environments, were poorly developed. This research project supported two graduate students, Miguel Cisneros Mata and Tim Lee. The objective of this research project was to advance the theoretical framework for such models, and to apply them to four species (three fish and a marine mammal) protected under the Endangered Species Act. Two of the species, the totoaba, a very large and long-lived marine groundfish, and the vacita, a very small dolphin, both from the Gulf of California, are extremely rare and very long lived, and thus are difficult to model using standard survey data. Data on salmonid populations are much better, and the fish are short lived. The fact that they pass through many habitats during their life cycle, however, complicates risk assessments.

Summary/Accomplishments (Outputs/Outcomes):

The methods developed included estimating vital rates from size-age associations using odoliths and other ancillary data, developing mathematics for entering correlated stochasticity to age- or size-structured population models, and estimating the creative rate from reports from fishermen and landing statistics. In collaboration with the work of Dr. Orlob and students reported elsewhere in this document, we also developed methods for embedding age-size dynamics over time into "particles" transported through multiple environments—a more computationally efficient procedure than classic individually-based population models, and thus more suitable for analyzing large populations over wide areas.

The following activities were accomplished:

• In work on the endangered winter run chinook salmon, we formulated delisting criteria that specifically accounted for the fact that when attempting to delist, population growth parameters would not be known, but would be estimated with a precision that varied with the number of samples taken and the precision of the abundance data. This model has been applied to a variety of applied fisheries analyses, supported by matching funding from Sea Grant, California Fish and Game, the National Oceanic and Atmospheric Administration, the National Marine Fisheries Service, and others, including the development of models for managing red sea urchins (e.g., Smith, et al., 1998; Morgan, et al., 2000a, 2000b), Sacramento Valley/Bay-Delta salmonids (e.g., Botsford and Brittnacher, 1998), and subsequently by Botsford and colleagues in recovery plan actions for Columbia River salmon, Atlantic lobsters, and a variety of fisheries in crisis.

• We provided important understandings of both the utility and the limitations of marine reserves as a means to protecting marine populations (Hastings and Botsford, 2003). The totoaba and vacita research were instrumental to the policies established by Mexican fisheries authorities in protecting the two species, and ultimately in the decision to establish the international Northern Gulf of California Biosphere Reserve that protect the major habitat of both species (Cisneros-Mata, et al., 1995; Morales-Bojórquez, et al., 2001).

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., RFA, Scientific Discipline, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Hydrology, Ecology, State, Monitoring/Modeling, Ecological Risk Assessment, Ecology and Ecosystems, environmental monitoring, aquatic ecosystem, risk assessment model, modeling, multiple stressors, fisheries, time series analysis, ecological risk, ecosystem health, environmental stress, California (CA), hydrologic modeling, ecological models

Relevant Websites: Exit

Progress and Final Reports:

Original Abstract
  • 1997
  • 1998
  • 1999 Progress Report

  • 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