I am a Microbiologist in the Studies Section.
I started with the USGS New Mexico Water Science Center in 2003 as a student studying Earth Science with an emphasis on subsurface (groundwater) microbiology. After receiving an MS in Biology in 2009, I worked as a Hydrologic Technician and later, Microbiologist, with the Oregon Water Science Center, Klamath Falls Field Station. In Oregon, I worked primarily on monitoring the frequent cyanobacteria blooms and associated toxins (“HABs”) and environmental parameters in Upper Klamath Lake. In 2018, I transferred to the Wyoming-Montana Water Science Center, and I am now building a microbiology/microbial ecology program and supporting water-quality studies throughout Montana and Wyoming.
Professional Experience
Microbiologist, USGS, Dec 2013-present
Hydrologist, USGS, Jan 2010-Dec 2013
Hydrologic Technician, USGS, April 2009-Jan 2010
Graduate Research Assistant, Portland State University, Sept 2005-April 2009
Hydrologic Technician, USGS, Jan 2003-June 2005
Education and Certifications
M.S. Biology, Portland State University, 2009
B.S. Earth and Planetary Sciences (Magna Cum Laude), University of New Mexico, 2005
B.S. Zoology (Summa Cum Laude), Texas State University, 1997
Science and Products
High-Resolution, Interagency Biosurveillance of Threatened Surface Waters in the United States
Advances in information technology now provide large volume, high-frequency data collection which may improve real-time biosurveillance and forecasting. But, big data streams present challenges for data management and timely analysis. As a first step in creating a data science pipeline for translating large datasets into meaningful interpretations, we created a cloud-hosted PostgreSQL database tha
Using High-Throughput DNA Sequencing, Genetic Fingerprinting, and Quantitative PCR as Tools for Monitoring Bloom-Forming and Toxigenic Cyanobacteria in Upper Klamath Lake, Oregon, 2013 and 2014
Monitoring the community structure and metabolic activities of cyanobacterial blooms in Upper Klamath Lake, Oregon, is critical to lake management because these blooms degrade water quality and produce toxic microcystins that are harmful to humans, domestic animals, and wildlife. Genetic tools, such as DNA fingerprinting by terminal restriction fragment length polymorphism (T-RFLP) analysis, high-
Filter Total Items: 13
Growth of coal mining operations in the Elk River Valley (Canada) linked to increasing solute transport of Se, NO3-, and SO42- into the transboundary Koocanusa Reservoir (USA-Canada)
Koocanusa Reservoir (KOC) is a waterbody that spans the United States (U.S.) and Canadian border. Increasing concentrations of total selenium (Se), nitrate + nitrite (NO3–, nitrite is insignificant or not present), and sulfate (SO42–) in KOC and downstream in the Kootenai River (Kootenay River in Canada) are tied to expanding coal mining operations in the Elk River Watershed, Canada. Using a paire
Authors
Meryl Biesiot Storb, Ashley Morgan Bussell, Sara L. Caldwell Eldridge, Robert M. Hirsch, Travis S. Schmidt
Spatiotemporal variations in copper, arsenic, cadmium, and zinc concentrations in surface water, fine-grained bed sediment, and aquatic macroinvertebrates in the upper Clark Fork Basin, western Montana—A 20-year synthesis, 1996–2016
The legacy of mining-related contamination in the upper Clark Fork Basin created an extensive longitudinal gradient in metal concentrations, extending from Silver Bow Creek to Lake Pend Oreille, Idaho. Downstream metal concentrations continue to decline, but, despite such improvements, the ecological health of much of the river remains uncertain. Understanding the long-term consequences of the Cla
Authors
Sara L. Caldwell Eldridge, Michelle I. Hornberger
Community for data integration 2019 project report
The U.S. Geological Survey Community for Data Integration annually supports small projects focusing on data integration for interdisciplinary research, innovative data management, and demonstration of new technologies. This report provides a summary of the 14 projects supported in fiscal year 2019 and outlines their goals, activities, and accomplishments. Proposals in 2019 were encouraged to addre
Authors
Amanda N. Liford, Caitlin M. Andrews, Aparna Bamzai, Joseph A. Bard, David S. Blehert, John B. Bradford, Wesley M. Daniel, Sara L. Caldwell Eldridge, Frank Engel, Jason A. Ferrante, Amy K. Gilmer, Margaret E. Hunter, Jeanne M. Jones, Benjamin Letcher, Frances L. Lightsom, Richard R. McDonald, Leah E. Morgan, Sasha C. Reed, Leslie Hsu
By
Ecosystems Mission Area, Water Resources Mission Area, Science Synthesis, Analysis and Research Program, Science Analytics and Synthesis (SAS) Program, Volcano Hazards Program, Community for Data Integration (CDI), Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center, National Wildlife Health Center, Oklahoma-Texas Water Science Center, Southwest Biological Science Center, Volcano Science Center, Western Geographic Science Center, Wetland and Aquatic Research Center , Woods Hole Coastal and Marine Science Center, Science Data Management
Sampling and analysis plan for the Koocanusa Reservoir and upper Kootenai River, Montana, water-quality monitoring program, 2021
In 2021, the U.S. Geological Survey will collect water-quality samples and environmental data from 3 sites in Koocanusa Reservoir and from 1 site in the Kootenai River. The transboundary Koocanusa Reservoir is in southeastern British Columbia, Canada, and northwestern Montana, United States, and was formed with the construction of Libby Dam on the Kootenai River 26 kilometers upstream from Libby,
Authors
Sara L. Caldwell Eldridge, Melissa A. Schaar, Chad B. Reese, Ashley M. Bussell, Thomas Chapin
Integrating environmental DNA results with diverse data sets to improve biosurveillance of river health
Autonomous, robotic environmental (e)DNA samplers now make it possible for biological observations to match the scale and quality of abiotic measurements collected by automated sensor networks. Merging these automated data streams may allow for improved insight into biotic responses to environmental change and stressors. Here, we merged eDNA data collected by robotic samplers installed at three U.
Authors
Adam J. Sepulveda, Andrew B. Hoegh, Joshua A. Gage, Sara L. Caldwell Eldridge, James M. Birch, Christian Stratton, Patrick R. Hutchins, Elliott Barnhart
Quantification of trace element loading in the upper Tenmile Creek drainage basin near Rimini, Montana, September 2011
The principle sources of trace elements entering upper Tenmile Creek, Montana, during September 2011, four trace metals and the metalloid arsenic, were identified and quantified by combining and analyzing streamflow data determined from tracer injection with trace-element concentrations and related water-quality data determined from synoptic sampling. The study reach was along upper Tenmile Creek,
Authors
Tom Cleasby, Sara L. Caldwell Eldridge
Contaminant concentrations in sediments, aquatic invertebrates, and fish in proximity to rail tracks used for coal transport in the Pacific Northwest: A baseline assessment
Railway transport of coal poses an environmental risk because coal dust contains polycyclic aromatic hydrocarbons (PAHs), mercury (Hg), and other trace metals. In the Pacific Northwest, proposed infrastructure projects could result in an increase in coal transport by train through the Columbia River corridor. Baseline information is needed on current distributions, levels, and spatial patterns of
Authors
Whitney B Hapke, Robert W. Black, Collin A. Eagles-Smith, Cassandra Smith, Lyndal Johnson, Gina M Ylitalo, Daryle Boyd, Jay W. Davis, Sara L. Caldwell Eldridge, Elena Nilsen
Annual variations in microcystin occurrence in Upper Klamath Lake, Oregon, based on high-throughput DNA sequencing, qPCR, and environmental parameters
Cyanobacteria-dominated blooms in Upper Klamath Lake, Oregon, create poor water quality and produce microcystins that may be detrimental to local wildlife and human health. Genetic tools, including high-throughput DNA sequencing and quantitative polymerase chain reaction (qPCR), have been shown to improve the identification and quantification of key groups associated with these blooms over more tr
Authors
Sara L. Caldwell Eldridge, Tamara M. Wood
Nutrient loads in the Lost River and Klamath River Basins, south-central Oregon and northern California, March 2012–March 2015
The U.S. Geological Survey and Bureau of Reclamation collected water-quality data from March 2012 to March 2015 at locations in the Lost River and Klamath River Basins, Oregon, in an effort to characterize water quality and compute a nutrient budget for the Bureau of Reclamation Klamath Reclamation Project. The study described in this report resulted in the following significant findings:Total pho
Authors
Liam N. Schenk, Marc A. Stewart, Sara L. Caldwell Eldridge
Using high-throughput DNA sequencing, genetic fingerprinting, and quantitative PCR as tools for monitoring bloom-forming and toxigenic cyanobacteria in Upper Klamath Lake, Oregon, 2013 and 2014
Monitoring the community structure and metabolic activities of cyanobacterial blooms in Upper Klamath Lake, Oregon, is critical to lake management because these blooms degrade water quality and produce toxic microcystins that are harmful to humans, domestic animals, and wildlife. Genetic tools, such as DNA fingerprinting by terminal restriction fragment length polymorphism (T-RFLP) analysis, high-
Authors
Sara L. Caldwell Eldridge, Conner Driscoll, Theo W. Dreher
Statistical analysis of the water-quality monitoring program, Upper Klamath Lake, Oregon, and optimization of the program for 2013 and beyond
Upper Klamath Lake in south-central Oregon has become increasingly eutrophic over the past century and now experiences seasonal cyanobacteria-dominated and potentially toxic phytoplankton blooms. Growth and decline of these blooms create poor water-quality conditions that can be detrimental to fish, including two resident endangered sucker species. Upper Klamath Lake is the primary water supply to
Authors
Sara L. Caldwell Eldridge, Susan A. Wherry, Tamara M. Wood
Water-quality data from Upper Klamath and Agency Lakes, Oregon, 2009-10
The U.S. Geological Survey Upper Klamath Lake water-quality monitoring program collected data from multiparameter continuous water-quality monitors, weekly water-quality samples, and meteorological stations during 2009 and 2010 from May through November each year. The results of these measurements and sample analyses, as well as quality-control data for the water-quality samples, are presented in
Authors
D. Blake Eldridge, Sara L. Caldwell Eldridge, Liam N. Schenk, Dwight Q. Tanner, Tamara M. Wood
Non-USGS Publications**
Caldwell Eldridge, S.L, Wood, T.M., Echols, K.R., and Topping, B.R., 2013, Microcystins, nutrient dynamics, and other environmental factors during blooms of non-microcystin-producing Aphanizomenon flos-aquae in Upper Klamath Lake, Oregon, 2009, Lake and Reservoir Management, 29: 68-81
Caldwell, S. Liu, Y. Ferrera, I., Beveridge, T. and Reysenbach, A.-L., 2010, Thermocrinis minervae sp. nov., a hydrogen- and sulfur-oxidizing, thermophilic member of the Aquificales from a Costa Rican terrestrial hot spring, International Journal of Systematic and Evolutionary Microbiology, 60: 338-343
Caldwell, S.L., Laidler, J.R., Brewer, E.A., Eberly, J.O., Sandborgh, S.C., and Colwell F.S., 2008, Anaerobic Oxidation of Methane: Mechanisms, Bioenergetics, and the Ecology of Associated Microorganisms, Environmental Science and Technology, 42: 18, 6791-6799
**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.
Science and Products
- Science
High-Resolution, Interagency Biosurveillance of Threatened Surface Waters in the United States
Advances in information technology now provide large volume, high-frequency data collection which may improve real-time biosurveillance and forecasting. But, big data streams present challenges for data management and timely analysis. As a first step in creating a data science pipeline for translating large datasets into meaningful interpretations, we created a cloud-hosted PostgreSQL database tha - Data
Using High-Throughput DNA Sequencing, Genetic Fingerprinting, and Quantitative PCR as Tools for Monitoring Bloom-Forming and Toxigenic Cyanobacteria in Upper Klamath Lake, Oregon, 2013 and 2014
Monitoring the community structure and metabolic activities of cyanobacterial blooms in Upper Klamath Lake, Oregon, is critical to lake management because these blooms degrade water quality and produce toxic microcystins that are harmful to humans, domestic animals, and wildlife. Genetic tools, such as DNA fingerprinting by terminal restriction fragment length polymorphism (T-RFLP) analysis, high- - Publications
Filter Total Items: 13
Growth of coal mining operations in the Elk River Valley (Canada) linked to increasing solute transport of Se, NO3-, and SO42- into the transboundary Koocanusa Reservoir (USA-Canada)
Koocanusa Reservoir (KOC) is a waterbody that spans the United States (U.S.) and Canadian border. Increasing concentrations of total selenium (Se), nitrate + nitrite (NO3–, nitrite is insignificant or not present), and sulfate (SO42–) in KOC and downstream in the Kootenai River (Kootenay River in Canada) are tied to expanding coal mining operations in the Elk River Watershed, Canada. Using a paireAuthorsMeryl Biesiot Storb, Ashley Morgan Bussell, Sara L. Caldwell Eldridge, Robert M. Hirsch, Travis S. SchmidtSpatiotemporal variations in copper, arsenic, cadmium, and zinc concentrations in surface water, fine-grained bed sediment, and aquatic macroinvertebrates in the upper Clark Fork Basin, western Montana—A 20-year synthesis, 1996–2016
The legacy of mining-related contamination in the upper Clark Fork Basin created an extensive longitudinal gradient in metal concentrations, extending from Silver Bow Creek to Lake Pend Oreille, Idaho. Downstream metal concentrations continue to decline, but, despite such improvements, the ecological health of much of the river remains uncertain. Understanding the long-term consequences of the ClaAuthorsSara L. Caldwell Eldridge, Michelle I. HornbergerCommunity for data integration 2019 project report
The U.S. Geological Survey Community for Data Integration annually supports small projects focusing on data integration for interdisciplinary research, innovative data management, and demonstration of new technologies. This report provides a summary of the 14 projects supported in fiscal year 2019 and outlines their goals, activities, and accomplishments. Proposals in 2019 were encouraged to addreAuthorsAmanda N. Liford, Caitlin M. Andrews, Aparna Bamzai, Joseph A. Bard, David S. Blehert, John B. Bradford, Wesley M. Daniel, Sara L. Caldwell Eldridge, Frank Engel, Jason A. Ferrante, Amy K. Gilmer, Margaret E. Hunter, Jeanne M. Jones, Benjamin Letcher, Frances L. Lightsom, Richard R. McDonald, Leah E. Morgan, Sasha C. Reed, Leslie HsuByEcosystems Mission Area, Water Resources Mission Area, Science Synthesis, Analysis and Research Program, Science Analytics and Synthesis (SAS) Program, Volcano Hazards Program, Community for Data Integration (CDI), Geology, Geophysics, and Geochemistry Science Center, Geosciences and Environmental Change Science Center, National Wildlife Health Center, Oklahoma-Texas Water Science Center, Southwest Biological Science Center, Volcano Science Center, Western Geographic Science Center, Wetland and Aquatic Research Center , Woods Hole Coastal and Marine Science Center, Science Data ManagementSampling and analysis plan for the Koocanusa Reservoir and upper Kootenai River, Montana, water-quality monitoring program, 2021
In 2021, the U.S. Geological Survey will collect water-quality samples and environmental data from 3 sites in Koocanusa Reservoir and from 1 site in the Kootenai River. The transboundary Koocanusa Reservoir is in southeastern British Columbia, Canada, and northwestern Montana, United States, and was formed with the construction of Libby Dam on the Kootenai River 26 kilometers upstream from Libby,AuthorsSara L. Caldwell Eldridge, Melissa A. Schaar, Chad B. Reese, Ashley M. Bussell, Thomas ChapinIntegrating environmental DNA results with diverse data sets to improve biosurveillance of river health
Autonomous, robotic environmental (e)DNA samplers now make it possible for biological observations to match the scale and quality of abiotic measurements collected by automated sensor networks. Merging these automated data streams may allow for improved insight into biotic responses to environmental change and stressors. Here, we merged eDNA data collected by robotic samplers installed at three U.AuthorsAdam J. Sepulveda, Andrew B. Hoegh, Joshua A. Gage, Sara L. Caldwell Eldridge, James M. Birch, Christian Stratton, Patrick R. Hutchins, Elliott BarnhartQuantification of trace element loading in the upper Tenmile Creek drainage basin near Rimini, Montana, September 2011
The principle sources of trace elements entering upper Tenmile Creek, Montana, during September 2011, four trace metals and the metalloid arsenic, were identified and quantified by combining and analyzing streamflow data determined from tracer injection with trace-element concentrations and related water-quality data determined from synoptic sampling. The study reach was along upper Tenmile Creek,AuthorsTom Cleasby, Sara L. Caldwell EldridgeContaminant concentrations in sediments, aquatic invertebrates, and fish in proximity to rail tracks used for coal transport in the Pacific Northwest: A baseline assessment
Railway transport of coal poses an environmental risk because coal dust contains polycyclic aromatic hydrocarbons (PAHs), mercury (Hg), and other trace metals. In the Pacific Northwest, proposed infrastructure projects could result in an increase in coal transport by train through the Columbia River corridor. Baseline information is needed on current distributions, levels, and spatial patterns ofAuthorsWhitney B Hapke, Robert W. Black, Collin A. Eagles-Smith, Cassandra Smith, Lyndal Johnson, Gina M Ylitalo, Daryle Boyd, Jay W. Davis, Sara L. Caldwell Eldridge, Elena NilsenAnnual variations in microcystin occurrence in Upper Klamath Lake, Oregon, based on high-throughput DNA sequencing, qPCR, and environmental parameters
Cyanobacteria-dominated blooms in Upper Klamath Lake, Oregon, create poor water quality and produce microcystins that may be detrimental to local wildlife and human health. Genetic tools, including high-throughput DNA sequencing and quantitative polymerase chain reaction (qPCR), have been shown to improve the identification and quantification of key groups associated with these blooms over more trAuthorsSara L. Caldwell Eldridge, Tamara M. WoodNutrient loads in the Lost River and Klamath River Basins, south-central Oregon and northern California, March 2012–March 2015
The U.S. Geological Survey and Bureau of Reclamation collected water-quality data from March 2012 to March 2015 at locations in the Lost River and Klamath River Basins, Oregon, in an effort to characterize water quality and compute a nutrient budget for the Bureau of Reclamation Klamath Reclamation Project. The study described in this report resulted in the following significant findings:Total phoAuthorsLiam N. Schenk, Marc A. Stewart, Sara L. Caldwell EldridgeUsing high-throughput DNA sequencing, genetic fingerprinting, and quantitative PCR as tools for monitoring bloom-forming and toxigenic cyanobacteria in Upper Klamath Lake, Oregon, 2013 and 2014
Monitoring the community structure and metabolic activities of cyanobacterial blooms in Upper Klamath Lake, Oregon, is critical to lake management because these blooms degrade water quality and produce toxic microcystins that are harmful to humans, domestic animals, and wildlife. Genetic tools, such as DNA fingerprinting by terminal restriction fragment length polymorphism (T-RFLP) analysis, high-AuthorsSara L. Caldwell Eldridge, Conner Driscoll, Theo W. DreherStatistical analysis of the water-quality monitoring program, Upper Klamath Lake, Oregon, and optimization of the program for 2013 and beyond
Upper Klamath Lake in south-central Oregon has become increasingly eutrophic over the past century and now experiences seasonal cyanobacteria-dominated and potentially toxic phytoplankton blooms. Growth and decline of these blooms create poor water-quality conditions that can be detrimental to fish, including two resident endangered sucker species. Upper Klamath Lake is the primary water supply toAuthorsSara L. Caldwell Eldridge, Susan A. Wherry, Tamara M. WoodWater-quality data from Upper Klamath and Agency Lakes, Oregon, 2009-10
The U.S. Geological Survey Upper Klamath Lake water-quality monitoring program collected data from multiparameter continuous water-quality monitors, weekly water-quality samples, and meteorological stations during 2009 and 2010 from May through November each year. The results of these measurements and sample analyses, as well as quality-control data for the water-quality samples, are presented inAuthorsD. Blake Eldridge, Sara L. Caldwell Eldridge, Liam N. Schenk, Dwight Q. Tanner, Tamara M. WoodNon-USGS Publications**
Caldwell Eldridge, S.L, Wood, T.M., Echols, K.R., and Topping, B.R., 2013, Microcystins, nutrient dynamics, and other environmental factors during blooms of non-microcystin-producing Aphanizomenon flos-aquae in Upper Klamath Lake, Oregon, 2009, Lake and Reservoir Management, 29: 68-81Caldwell, S. Liu, Y. Ferrera, I., Beveridge, T. and Reysenbach, A.-L., 2010, Thermocrinis minervae sp. nov., a hydrogen- and sulfur-oxidizing, thermophilic member of the Aquificales from a Costa Rican terrestrial hot spring, International Journal of Systematic and Evolutionary Microbiology, 60: 338-343Caldwell, S.L., Laidler, J.R., Brewer, E.A., Eberly, J.O., Sandborgh, S.C., and Colwell F.S., 2008, Anaerobic Oxidation of Methane: Mechanisms, Bioenergetics, and the Ecology of Associated Microorganisms, Environmental Science and Technology, 42: 18, 6791-6799**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.