Grantee Research Project Results

1996 Progress Report: Effects of Nutrients on Algal Growth

EPA Grant Number: R825433C061
Subproject: this is subproject number 061 , 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: Effects of Nutrients on Algal Growth
Investigators: Richerson, Peter , Goldman, Charles R.
Institution: University of California - Davis
EPA Project Officer: Packard, Benjamin H
Project Period: June 30, 1995 through June 30, 1998
Project Period Covered by this Report: June 30, 1995 through June 30, 1996
RFA: Exploratory Environmental Research Centers (1992) RFA Text |  Recipients Lists
Research Category: Center for Ecological Health Research , Targeted Research

Objective:

This project is focused on the effects of nutrients on algal growth and N fixation. We have conducted a program of bioassays which replicates old work showing that the lake is N limited, and that N fixation is in turn Fe limited. Fe is thus the master variable in the trophic dynamics of Clear Lake, and possibly a large class of alkaline lakes in arid regions. A fair number of lakes are known to be N limited, contrary to the hypothesis that N fixation should make P limiting in most lakes. These findings have stimulated the initiation of a major subprogram on Fe geochemistry. With assistance from the Analytical Core, we are developing state-of-the-art methods for speciating Fe. Measurements of water column Fe show substantial elevation of particulate but not dissolved Fe just above the sediment-water interface. Nevertheless, water from just above the sediments stimulates algal growth and N fixation in bioassays, whereas water within the sediment does not. In collaboration with Lake County, the Hopland Field Station, and the Clean Lakes project, we have added basic Fe measurements to ongoing nutrient-monitoring study of stream inflows and internal loading of P. We have also conducted a short coring project to attempt to understand why large amounts of P began to cycle in Clear Lake during the drought of the last decade.

A year-long limnological monitoring program was begun in June 1995 and will continue to next June. So far the pattern is clear that (1) in summer (from July to Sept.) total Fe, total P, soluble reactive P, and ammonium increase with the depth when dissolved oxygen (DO) decreases with depth and (2) soluble Fe and nitrate are not affected by DO and remain low in the water column.

This subproject has been combined with A1.e and the future plans for its work are reported there.

Supplemental Keywords:

nutrients, algae, algal, nitrogen, iron., RFA, Scientific Discipline, Toxics, Water, Waste, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Ecosystem Protection, exploratory research environmental biology, mercury transport, Geochemistry, Environmental Chemistry, Ecosystem/Assessment/Indicators, Restoration, HAPS, Ecological Effects - Environmental Exposure & Risk, Fate & Transport, Environmental Microbiology, Microbiology, Monitoring/Modeling, Biochemistry, decision-making, 33/50, Aquatic Ecosystem Restoration, West Coast, Geology, Environmental Engineering, Engineering, Ecological Indicators, valuation, stressors, mercury loading, nutrients, Clear Lake, Sulphur Bank Mercury Mine, algal growth, algal growth, mining, mercury & mercury compounds, Mercury Compounds, bioassay, phosphorus, nutrient monitoring , iron (Fe) , transport, microbiological aspects

Progress and Final Reports:

Original Abstract

1995

Final

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