Tamara Kraus
Tamara Kraus is a Research Soil Scientist at the California Water Science Center.
Tamara Kraus received a master's degree in Agronomy and a doctoral degree in Soils and Biogeochemistry from the University of California, Davis. She has been working at the USGS California Water Science Center (CAWSC) in Sacramento since 2004, where she does research on the cycling of carbon and nutrients, and the linkages between terrestrial and aquatic systems. Her projects span a range of topics from identifying sources of dissolved organic carbon and to inform drinking water quality management, to using constructed wetlands to reverse subsidence, to the application of in situ coagulation to remove mercury from surface waters, to understanding the links between nutrients and phytoplankton.
Professional Experience
2010-present Soil Scientist, US Geological Survey, Sacramento, CA
2006-2009 Post Doctoral Researcher, US Geological Survey through UC Davis, Sacramento, CA
2004-2005 National Research Council Post Doctoral Fellow with US Geological Survey, Sacramento, CA
1996-2003 Research Assistant: Soil Chemistry Lab, , University of California, Davis, CA
1996-2003 Teaching Assistant: Soils and Biogeochemistry, , University of California, Davis, CA
1995-1996 Post-Graduate Researcher/Project Manager, University of California, Davis, CA
1992-1994 Research Assistant: Agronomy, University of California, Davis, CA
Education and Certifications
Ph.D., Soils and Biogeochemistry, 2002, University of California, Davis , CA Dissertation: Tannins and Nutrient Dynamics in Forest Soils: Plant-Litter-Soil Interactions
M.S., Agronomy and Range Science, 1994, University of California, Davis, CAThesis: Weed Abundance and Competition in Water-Seeded versus Drill-Seeded Rice in California
B.A., Biology and Society: Agriculture and the Environment, 1989, College of Arts and Sciences Cornell University, Ithaca, NY
Science and Products
Decomposition of Organic Soils in the Sacramento-San Joaquin Delta
Low Intensity Chemical Dosing (LICD)
Effects of Aquatic Vegetation on Water Quality and Residence Time in the Bay-Delta
Assessment of nutrients and water-quality constituents at the Sacramento-San Joaquin River Confluence during a phytoplankton bloom in July 2017
High-Resolution Measurements to Identify Effects of Aquatic Vegetation on Water Quality and Stratification
Chemical and Stable Isotope Data for Discrete Water Samples Collected in the Northern Sacramento-San Joaquin Delta, 2011-2012
Assessing spatial variability of nutrients and related water quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2018 High resolution mapping surveys (ver. 2.0, October 2023)
Chemically enhanced treatment wetland to improve water quality and mitigate land subsidence in the Sacramento-San Joaquin Delta: Cost and design considerations
Sequestration and transformation in chemically enhanced treatment wetlands: DOC, DBPPs and Nutrients
Aluminum- and iron-based coagulation for in-situ removal of dissolved organic carbon, disinfection byproducts, mercury and other constituents from agricultural drain water
Effects of ferric sulfate and polyaluminum chloride coagulation enhanced treatment wetlands on Typha growth, soil and water chemistry
Procedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter
Sediment accretion and carbon storage in constructed wetlands receiving water treated with metal-based coagulants
Wetlands receiving water treated with coagulants improve water quality by removing dissolved organic carbon and disinfection byproduct precursors
Use of flow cytometry and stable isotope analysis to determine phytoplankton uptake of wastewater derived ammonium in a nutrient-rich river
Using paired in situ high frequency nitrate measurements to better understand controls on nitrate concentrations and estimate nitrification rates in a wastewater-impacted river
An introduction to high-frequency nutrient and biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California
Synthesis of data from high-frequency nutrient and associated biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California
Designing a high-frequency nutrient and biogeochemical monitoring network for the Sacramento–San Joaquin Delta, northern California
Science and Products
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Decomposition of Organic Soils in the Sacramento-San Joaquin Delta
The Sacramento-San Joaquin Delta of California was once a great tidal freshwater marsh. It is blanketed by peat and peaty alluvium deposited where streams originating in the Sierra Nevada, Coast Ranges, and South Cascade Range enter San Francisco Bay. In the late 1800s, levees were built along the stream channels, and the land thus protected from flooding was drained, cleared, and planted (...Low Intensity Chemical Dosing (LICD)
Rivers, wetlands, and agricultural operations supply natural organic material to the Sacramento-San Joaquin Delta (Delta) and the San Francisco Estuary. This natural organic matter provides many ecosystem benefits, but it also adversely affects drinking water. During drinking water treatment, chlorine added for purposes of pathogen control reacts with dissolved organic carbon (DOC) in the water to...Effects of Aquatic Vegetation on Water Quality and Residence Time in the Bay-Delta
The spread of invasive aquatic vegetation in the Sacramento-San Joaquin Delta is having a profound impact on the Delta’s natural habitat. The presence of these “aquatic weeds” has been shown to alter water velocity and increase water clarity, posing threats to native fish species, specifically the threatened Delta Smelt. These aquatic plants can also affect the foodweb by altering nutrient... - Data
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Assessment of nutrients and water-quality constituents at the Sacramento-San Joaquin River Confluence during a phytoplankton bloom in July 2017
This report documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta in the Sacramento-San Joaquin River Delta of California, USA. The data set includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, turbidity, and chlorophyll. Data-collection were conducted oHigh-Resolution Measurements to Identify Effects of Aquatic Vegetation on Water Quality and Stratification
The dataset documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta of the Sacramento-San Joaquin River Delta of California, USA. The dataset includes surface mapping, depth profile, and discrete data for nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, and chlChemical and Stable Isotope Data for Discrete Water Samples Collected in the Northern Sacramento-San Joaquin Delta, 2011-2012
This data set consists of chemical and stable isotope data obtained through the analysis of discrete water samples collected from 14 fixed sampling locations in the northern Sacramento-San Joaquin Delta at roughly monthly intervals between April 2011 and November 2012.Assessing spatial variability of nutrients and related water quality constituents in the California Sacramento-San Joaquin Delta at the landscape scale: 2018 High resolution mapping surveys (ver. 2.0, October 2023)
The dataset documents the spatial and temporal variability of nutrients and related water quality parameters at high spatial resolution in the North Delta, Central Delta, and the Western Delta out to Suisun Bay in the Sacramento-San Joaquin River Delta of California, USA. The dataset includes nitrate, ammonium, phosphate, dissolved organic carbon, temperature, conductivity, dissolved oxygen, and c - Publications
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Chemically enhanced treatment wetland to improve water quality and mitigate land subsidence in the Sacramento-San Joaquin Delta: Cost and design considerations
Water quality impairment and land surface subsidence threaten the viability of the Sacramento-San Joaquin Delta (Delta), a critical component of California’s water conveyance system. Current day irrigation drainage through Delta island peat soils impacts drinking water treatment and is linked to mercury transport, potentially posing both ecological and public health concerns. Hybrid coagulation-trAuthorsPhilip A. M. Bachand, Tamara E. C. Kraus, William R. Horwath, Nathan R. Hatch, Sandra M. BachandSequestration and transformation in chemically enhanced treatment wetlands: DOC, DBPPs and Nutrients
We examined the effectiveness of chemically enhanced treatment wetlands (CETWs), wetlands that received water treated with coagulants, to remove dissolved organic carbon (DOC), disinfection byproduct precursors (DBPPs), nutrients and metals from agricultural drain water. Wetlands consisted of controls with no coagulant addition, ferric sulfate dosed and polyaluminum chloride dosed treatments. CETWAuthorsPhilip A. M. Bachand, Sandra M. Bachand, Tamara E. C. Kraus, Dylan Stern, Yan Ling Liang, William R. HorwathAluminum- and iron-based coagulation for in-situ removal of dissolved organic carbon, disinfection byproducts, mercury and other constituents from agricultural drain water
Agricultural production on wetland soils can be significant sources of dissolved organic carbon (DOC), disinfection byproduct precursors, mercury and nutrients to downstream water bodies and accelerate land subsidence. Presented as a potential solution for in-situ water quality improvement and land subsidence mitigation, chemically enhanced treatment wetlands (CETWs) were used to leverage both coaAuthorsSandra M. Bachand, Tamara E. C. Kraus, Dylan Stern, Yan Ling Liang, William R. Horwath, Philip A. M. BachandEffects of ferric sulfate and polyaluminum chloride coagulation enhanced treatment wetlands on Typha growth, soil and water chemistry
Land surface subsidence is a concern in many deltas worldwide as it contributes to water quality degradation, loss of fertile land and increased potential for levee failure. As a possible solution to these concerns, on-site coagulation enhanced treatment wetlands(CETWs), coagulation water treatment followed by wetland passage serving as a settling basin, were implemented in a field-scale study locAuthorsYan Ling Liang, Tamara E. C. Kraus, Lucas C. R. Silva, Philip A. M. Bachand, Sandra M. Bachand, Timothy A. Doane, William R. HorwathProcedures for using the Horiba Scientific Aqualog® fluorometer to measure absorbance and fluorescence from dissolved organic matter
Advances in spectroscopic techniques have led to an increase in the use of optical measurements (absorbance and fluorescence) to assess dissolved organic matter composition and infer sources and processing. Although optical measurements are easy to make, they can be affected by many variables rendering them less comparable, including by inconsistencies in sample collection (for example, filter porAuthorsAngela M. Hansen, Jacob Fleck, Tamara E. C. Kraus, Bryan D. Downing, Travis von Dessonneck, Brian A. BergamaschiSediment accretion and carbon storage in constructed wetlands receiving water treated with metal-based coagulants
In many regions of the world, subsidence of organic rich soils threatens levee stability and freshwater supply, and continued oxidative loss of organic matter contributes to greenhouse gas production. To counter subsidence in the Sacramento-San Joaquin Delta of northern California, we examined the feasibility of using constructed wetlands receiving drainage water treated with metal-based coagulantAuthorsElizabeth B. Stumpner, Tamara E. C. Kraus, Yan Liang, Sandra M. Bachand, William R. Horwath, Philip A.M. BachandWetlands receiving water treated with coagulants improve water quality by removing dissolved organic carbon and disinfection byproduct precursors
Constructed wetlands are used worldwide to improve water quality while also providing critical wetland habitat. However, wetlands have the potential to negatively impact drinking water quality by exporting dissolved organic carbon (DOC) that upon disinfection can form disinfection byproducts (DBPs) like trihalomethanes (THMs) and haloacetic acids (HAAs). We used a replicated field-scale study locaAuthorsAngela M. Hansen, Tamara E. C. Kraus, Sandra M. Bachand, William R. Horwath, Philip A.M. BachandUse of flow cytometry and stable isotope analysis to determine phytoplankton uptake of wastewater derived ammonium in a nutrient-rich river
Anthropogenic alteration of the form and concentration of nitrogen (N) in aquatic ecosystems is widespread. Understanding availability and uptake of different N sources at the base of aquatic food webs is critical to establishment of effective nutrient management programs. Stable isotopes of N (14N, 15N) are often used to trace the sources of N fueling aquatic primary production, but effective useAuthorsCalla M. Schmidt, Tamara E. C. Kraus, Megan B. Young, Carol KendallUsing paired in situ high frequency nitrate measurements to better understand controls on nitrate concentrations and estimate nitrification rates in a wastewater-impacted river
We used paired continuous nitrate ( ) measurements along a tidally affected river receiving wastewater discharge rich in ammonium ( ) to quantify rates of change in concentration ( ) and estimate nitrification rates. sensors were deployed 30 km apart in the Sacramento River, California (USA), with the upstream station located immediately above the regional wastewater treatment plant (WWTP). We uAuthorsTamara E. C. Kraus, Katy O'Donnell, Bryan D. Downing, Jon R. Burau, Brian A. BergamaschiAn introduction to high-frequency nutrient and biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California
Executive SummaryThis report is the first in a series of three reports that provide information about high-frequency (HF) nutrient and biogeochemical monitoring in the Sacramento–San Joaquin Delta of northern California (Delta). This first report provides an introduction to the reasons for and fundamental concepts behind collecting HF measurements, and describes the benefits associated with a realAuthorsTamara E.C. Kraus, Brian A. Bergamaschi, Bryan D. DowningSynthesis of data from high-frequency nutrient and associated biogeochemical monitoring for the Sacramento–San Joaquin Delta, northern California
Executive SummaryThis report is the second in a series of three reports that provide information about high-frequency (HF) nutrient and biogeochemical monitoring in the Sacramento–San Joaquin Delta of northern California (Delta). The purpose of this report is to synthesize the data available from a nutrient and water-quality HF (about every 15 minutes) monitoring network operated by the U.S. GeoloAuthorsBryan D. Downing, Brian A. Bergamaschi, Tamara E.C. KrausDesigning a high-frequency nutrient and biogeochemical monitoring network for the Sacramento–San Joaquin Delta, northern California
Executive SummaryThis report is the third in a series of three reports that provide information about how high-frequency (HF) nutrient monitoring may be used to assess nutrient inputs and dynamics in the Sacramento–San Joaquin Delta, California (Delta). The purpose of this report is to provide the background, principles, and considerations for designing an HF nutrient-monitoring network for the DeAuthorsBrian A. Bergamaschi, Bryan D. Downing, Tamara E.C. Kraus, Brian A. Pellerin - Web Tools
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