Grantee Research Project Results

1996 Progress Report: The History of Anthropogenic Effects

EPA Grant Number: R825433C019
Subproject: this is subproject number 019 , 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: UC Davis Center for Children's Environmental Health and Disease Prevention
Center Director: Van de Water, Judith
Title: The History of Anthropogenic Effects
Investigators: Richerson, Peter , Suchanek, Thomas
Current Investigators: Richerson, Peter , Nelson, Douglas , Anderson, Daniel , Suchanek, Thomas
Institution: University of California - Davis
EPA Project Officer: Packard, Benjamin H
Project Period: October 1, 1996 through September 30, 2000
Project Period Covered by this Report: October 1, 1996 through September 30, 1997
RFA: Exploratory Environmental Research Centers (1992) RFA Text |  Recipients Lists
Research Category: Center for Ecological Health Research , Targeted Research

Objective:

Sediment cores are useful tools in reconstructing the history of aquatic ecosystems. For many parameters, stresses and responses at the time of sediment deposition cause specific signals in a core.

Current Status:

The USGS raised some very deep cores (115m long, representing 450,000 years) during the 1970s and 80s for work on the long time scale, and the UC Davis Mercury Project raised some shallow cores (~1m, representing 50-75 years) during 1992 to investigate changes in sediment mercury since the last mining episode. We are now collecting cores of 2-3 meters length, which will reflect the last 300-400 years of changes in the lake in order to assess the kinds of natural and anthropogenic stresses applied at various time frames since the advent of European colonization. In collaboration with several other projects, we are also investigating the documentary history available to reconstruct stress events and responses. A combination of cores and standard historical analysis, together with process oriented investigations, should result in an excellent reconstruction of past stresses and their effects. The use of museum specimens for retrospective analysis of exposure is described in Project B.3. Ultimately, we intend to synthesize the information from the cores, historical analysis, and the long-term monitoring record into as complete a picture as possible of the anthropogenic and natural stresses that have impacted the Clear Lake watershed.

For the past year we have been designing a sampling protocol and methodology and doing the historical legwork for the Clear Lake ecosystem. Because Clear Lake is relatively shallow, we have been able to use a simple hand-driven coring device to sample the whole historical sequence well back into the pre-European period. These cores will be dated (²¹⁰Pb analysis) and analyzed for a large number of parameters (x-ray, nutrients, Hg, diatoms, pollen, algal pigments, microbial community structure, etc.) These measurements will allow us to reconstruct the effects of major events in the basin (i.e. dam construction, dential logging, road building, stream channel disturbance, mining activities, residential development, etc.) on physical and biological responses such as sediment rate and planktonic community composition.

Some data are now available from our first two cores, raised from the large Upper Arm basin. They are remarkably consistent in showing very small effects of early settlement (including mining), but very big changes in recent decades. Mercury concentrations in cores increased by a factor of ten, nitrogen content fell by a factor of three, and the percent of inorganic matter in cores significantly increases at a depth of 35 cm in one core and 70 cm in the other. There is a small increase in mercury above background about 70 cm deeper in both cores. The cores are as yet undated, and previous short cores have estimated sedimentation rates of from about 0.8 to 1.35 cm/yr. The biggest stresses on the system have likely occurred in the last 45-70 years, and there are a remarkable number of large changes that begin at the same time.

Future Activities:

During the next year, we will raise 6 cores from Clear Lake and have them analyzed for the different parameters. There will be 2 cores raised from each of the three basins of the lake. By doing this, we can test how deposition has changed, both within the basins and between the basins. Our cores will be analyzed for many of the same methods and for many of the same parameters as the cores previously retrieved from Lake Tahoe. (See Section C. 1) We will collaborate with the Tahoe group on a synthetic and comparative project to compare the anthropogenic impacts in these two basins.

Supplemental Keywords:

sediment cores, sampling, ecosystem., RFA, Ecosystem Protection/Environmental Exposure & Risk, Scientific Discipline, Geographic Area, Water, Waste, Toxics, Aquatic Ecosystem, Restoration, Aquatic Ecosystems & Estuarine Research, Ecological Indicators, Environmental History, Engineering, Fate & Transport, West Coast, Ecosystem Protection, Aquatic Ecosystem Restoration, mercury transport, HAPS, Environmental Chemistry, 33/50, Ecosystem/Assessment/Indicators, Microbiology, Monitoring/Modeling, Geochemistry, Geology, Ecological Effects - Environmental Exposure & Risk, Environmental Engineering, mercury & mercury compounds, mining, lake ecosystem, sediment cores, Sulphur Bank Mercury Mine, ecosystem indicators, Clear Lake , Mercury Compounds, anthropogenic stresses, mercury loading, transport, aquatic ecosystems, nutrients, Clear Lake, anthropogenic stress, mercury

Progress and Final Reports:

Original Abstract

1997

1998

1999

Final Report

Main Center Abstract and Reports:

R825433    UC Davis Center for Children's Environmental Health and Disease Prevention

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