Natalie K Day
Natalie is a Biologist with the Colorado Water Science Center
Natalie is a cross-disciplinary biologist working on the Colorado Plateau. She seeks to provide relevant information to land managers, policy makers, and the public. Some of her research interests include assessing the effects of land disturbance in drylands on regional hydrology, understanding controls on riverine algal blooms, and assessing long-term changes in streamflow and water quality. Natalie works to improve the sharing of information among different fields and conducts research that is collaborative and useful.
Professional Experience
Biologist, USGS-Colorado Water Science Center, Grand Junction, CO, Fall 2019-present
Biologist, USGS-Canyonland Research Station, Moab, UT, 2016-2019
Biological Field Technician, USGS-Canyonland Research Station, Moab, UT, 2010-2011
Research Assistant, Utah Water Research Lab, Logan, UT, 2009-2010
Research Assistant, Biogeochemistry Lab, Utah State University, Logan, UT, 2008-2009
Student Technician, National Science Foundation, Toolik Lake, AK, advised by George Kling, 2007
Student Technician, National Science Foundation, Hubbard Brook Experimental Forest, advised by Gene Likens , 2007
Education and Certifications
Master of Science in Biogeochemistry, the University of Wyoming, Laramie, WY, 2015
Focus: Nitrogen cycling in headwater streams in Rocky Mountain National Park, CO
Advised by Robert O. Hall, Jr.Bachelor of Arts in Biology, Lewis & Clark College, Portland, OR, 2008
Focus: Aquatic biogeochemistry
Science and Products
Assessment of Mercury and Selenium Accumulation in Upper Colorado River Basin Fish
More than 50 years of existing mercury and selenium concentrations in native and nonnative fish species residing in streams within the Upper Colorado River Basin were compiled and analyzed to provide an understanding of concentrations among different species, sampling years, and locations to determine potential health risks. Concentrations of mercury and selenium were above health benchmarks in 13...
Characterization of Streamflow, Suspended Sediment, and Nutrients in the Upper Yampa River Basin
The Upper Yampa River Basin (UYRB) drains approximately 1,800 square miles west of the Continental Divide in northwestern Colorado. In 2019, the USGS, in cooperation with local stakeholders in the UYRB water community, initiated a study to characterize streamflow, suspended sediment, and nutrients using historic and recently acquired water-quality data from a long-term monitoring program initiated...
Analyte concentrations and stable isotopes in fish tissue collected across the upper Colorado River Basin in 2016 and 2017 Analyte concentrations and stable isotopes in fish tissue collected across the upper Colorado River Basin in 2016 and 2017
These data were compiled to examine analyte concentrations, including mercury and selenium, and stable isotopes in native and non-native fish across rivers in the Upper Colorado River Basin. Data were collected in 2016 and 2017. Tissue samples were collected as whole-body or muscle plugs (biopsies). Tissue samples were analyzed for stable isotopes in 772 samples, for selenium and 54...
Long-term trends in annual, seasonal, and monthly streamflow metrics at streamgages in the Upper Colorado River Basin, 1981-2022 Long-term trends in annual, seasonal, and monthly streamflow metrics at streamgages in the Upper Colorado River Basin, 1981-2022
Identifying long-term trends in water availability, including surface water quantity, is a key part of the U.S. Geological Survey (USGS) Integrated Water Availability Assessments (IWAAs) mission. This data release includes input and output data used in Mann-Kendall trend analyses to characterize streamflow conditions at 124 USGS streamgages in the Upper Colorado River Basin for water...
Benthic algae community composition data from the Colorado River Basin, Colorado, from 2022-23 Benthic algae community composition data from the Colorado River Basin, Colorado, from 2022-23
This dataset includes benthic algae community composition data in the Colorado River near Cameo, Colorado, U.S. Geological Survey (USGS) site number 09095500, from 2022 to 2023, and from three sites in the upper White River Basin, Colorado, in 2022. Taxonomic classification of algae species is not known well in theses rivers, and this study was conducted to record different algae species...
Erosion rates and salinity and selenium yields in a basin near Rangely, Colorado following the 2017 Dead Dog wildfire as modeled by WEPP and measured from UAV Erosion rates and salinity and selenium yields in a basin near Rangely, Colorado following the 2017 Dead Dog wildfire as modeled by WEPP and measured from UAV
This data release accompanies a U.S Geological Survey study that assessed sediment, salinity, and selenium yields following the Dead Dog wildfire in northwestern Colorado. The Dead Dog fire ignited on June 11, 2017, near Rangely, Colorado, and burned over 17,000 acres, including the B2 study area. Two methodologies were used to quantify erosion and associated salinity and sediment yields...
Channel Characteristics, benthic algae, and water quality model data for selected sites in the upper White River Basin, Colorado, 2018-21 Channel Characteristics, benthic algae, and water quality model data for selected sites in the upper White River Basin, Colorado, 2018-21
This U.S. Geological Survey (USGS) data release provides benthic algae and stream channel characteristics data collected from 20 water-quality sites in the Upper White River Basin, Colorado., during 2018-2021. Also included are input and output data from streamflow and water-quality regression models used to characterize streamflow and water-quality conditions at 3 sites in the Upper...
Orthoimagery, digital elevation, digital terrain, final surface, and vegetation classification models for four stream catchments in western Colorado 2016 Orthoimagery, digital elevation, digital terrain, final surface, and vegetation classification models for four stream catchments in western Colorado 2016
Unmanned Aerial System (UAS) flights were conducted over four stream catchments in Rio Blanco County, Colorado, during the summer of 2016. Two sties had active oil and gas operations within the basin whereas the other two sites did not. Structure from motion (SfM) was used to align raw images and create a dense point cloud, georectified orthoimage, and Digital Elevation Model (DEM) for...
Input and output data from streamflow and water-quality regression models used to characterize streamflow and water-quality conditions in the Upper Yampa River Basin, Colorado, from 1992-2018 Input and output data from streamflow and water-quality regression models used to characterize streamflow and water-quality conditions in the Upper Yampa River Basin, Colorado, from 1992-2018
This dataset includes input and output data from streamflow and water-quality regression models used to characterize streamflow and water-quality conditions in the Upper Yampa River Basin, Colorado from 1999-2018. All input data, including discrete and continuous streamflows and discrete concentrations of suspended sediment, Kjeldahl nitrogen, and total phosphorus, were compiled from the...
Surrogate regression models for computation of time series suspended-sediment concentrations at Muddy Creek above Paonia Reservoir, Anthracite Creek above mouth near Somerset, and North Fork Gunnison below Raven Gulch near Somerset, Colorado Surrogate regression models for computation of time series suspended-sediment concentrations at Muddy Creek above Paonia Reservoir, Anthracite Creek above mouth near Somerset, and North Fork Gunnison below Raven Gulch near Somerset, Colorado
This model archive summary documents the surrogate regression model used to compute suspended-sediment concentrations at Muddy Creek above Paonia Reservoir, CO, USGS site number 385903107210800. The methods used follow U.S. Geological Survey (USGS) guidance as referenced in relevant Office of Surface Water Technical Memorandum (TM) 2016.07 and Office of Water Quality TM 2016.10, and USGS...
Fish tissue mercury and selenium concentrations in Upper Colorado River Basin: 1962-2011 Fish tissue mercury and selenium concentrations in Upper Colorado River Basin: 1962-2011
These data were compiled to study mercury and selenium concentrations in fish species and assemblages in lotic waterbodies across the Upper Colorado River Basin. Data were compiled from State and Federal agencies. This data table contains raw concentration data, as well as standardized concentrations corrected for differences based on sample type (i.e., tissue type), species-specific...
Salinity or sum of constituents— Methods comparison for computing dissolved solids concentrations in streams of the Upper Colorado River Basin Salinity or sum of constituents— Methods comparison for computing dissolved solids concentrations in streams of the Upper Colorado River Basin
The Colorado River is an important water source in the southwestern United States and northern Mexico. High concentrations of dissolved solids in the river, sourced mainly from the Upper Colorado River Basin (UCOL), cause hundreds of millions of dollars in damages annually to crops and infrastructure. Determinations of total dissolved solids (TDS) in river and tributary samples often...
Authors
Fred D. Tillman, Matthew P. Miller, Daniel Wise, R. Blaine McCleskey, Natalie K. Day
Wildland fire effects on sediment, salinity, and selenium yields in a basin underlain by Cretaceous marine shales near Rangely, Colorado Wildland fire effects on sediment, salinity, and selenium yields in a basin underlain by Cretaceous marine shales near Rangely, Colorado
Understanding and quantifying soil erosion from rangelands is a high priority for land managers, especially in areas underlain by Cretaceous Mancos Shale, which is a natural source of sediment, salinity, and selenium to surface waters in many areas of western Colorado and eastern Utah. The purpose of this report is to present the results of a U.S. Geological Survey study that assessed...
Authors
Natalie K. Day, Todd M. Preston, Patrick C. Longley
Investigation of potential factors controlling benthic algae in the upper White River Basin, Colorado, 2018–21 Investigation of potential factors controlling benthic algae in the upper White River Basin, Colorado, 2018–21
Nuisance levels of benthic filamentous green algae are becoming increasingly common in surface waters of Colorado and the western United States. In 2018 the U.S. Geological Survey began a study in cooperation with the White River and Douglas Creek Conservation Districts, Colorado River Basin Salinity Control Forum, and the Colorado River Water Conservation District to collect and analyze...
Authors
Natalie K. Day, Mark F. Henneberg
Potential factors controlling benthic algae in the upper White River Basin, Colorado, 2018–21 Potential factors controlling benthic algae in the upper White River Basin, Colorado, 2018–21
Nuisance levels of benthic algae are becoming increasingly common in surface waters of the western United States and can compromise aesthetic quality, limit recreational activities, block water infrastructure, and negatively affect aquatic life. In cooperation with the White River and Douglas Creek Conservation Districts, the Colorado River Basin Salinity Control Forum, and the Colorado...
Authors
Rachel G. Gidley, Natalie K. Day
Characterization of streamflow and nutrient occurrence in the upper White River Basin, Colorado, 1980–2020 Characterization of streamflow and nutrient occurrence in the upper White River Basin, Colorado, 1980–2020
In 2016, Colorado Parks and Wildlife identified filamentous algae collected from the main stem White River as Cladophora glomerata, a pervasive nuisance aquatic alga. Excessive levels of filamentous algae can compromise aesthetic quality, limit recreational activities, and have negative effects on aquatic life including strong fluctuations in dissolved oxygen levels and a reduction in...
Authors
Natalie K. Day
A review of current capabilities and science gaps in water supply data, modeling, and trends for water availability assessments in the Upper Colorado River Basin A review of current capabilities and science gaps in water supply data, modeling, and trends for water availability assessments in the Upper Colorado River Basin
The Colorado River is a critical water resource in the southwestern United States, supplying drinking water for 40 million people in the region and water for irrigation of 2.2 million hectares of land. Extended drought in the Upper Colorado River Basin (UCOL) and the prospect of a warmer climate in the future pose water availability challenges for those charged with managing the river...
Authors
Fred D. Tillman, Natalie K. Day, Matthew P. Miller, Olivia L. Miller, Christine A. Rumsey, Daniel Wise, Patrick C. Longley, Morgan C. McDonnell
Analysis of Escherichia coli, total recoverable iron, and dissolved selenium concentrations, loading, and identifying data gaps for selected 303(d) listed streams, Grand Valley, western Colorado, 1980–2018 Analysis of Escherichia coli, total recoverable iron, and dissolved selenium concentrations, loading, and identifying data gaps for selected 303(d) listed streams, Grand Valley, western Colorado, 1980–2018
Tributaries to the Colorado River in the Grand Valley in western Colorado (segment COLCLC13b) have been placed on the State of Colorado 303(d) list as impaired for Escherichia coli (E. coli), total recoverable iron, and dissolved selenium. The Colorado Department of Public Health and Environment Water Quality Control Division is required to develop total maximum daily loads for these...
Authors
Lisa D. Miller, Rachel G. Gidley, Natalie K. Day, Judith C. Thomas
Assessment of streamflow and water quality in the Upper Yampa River Basin, Colorado, 1992–2018 Assessment of streamflow and water quality in the Upper Yampa River Basin, Colorado, 1992–2018
The Upper Yampa River Basin drains approximately 2,100 square miles west of the Continental Divide in north-western Colorado. There is a growing need to understand potential changes in the quantity and quality of water resources as the basin is undergoing increasing land and water development to support growing municipal, industrial, and recreational needs. The U.S. Geological Survey, in...
Authors
Natalie K. Day
Mercury and selenium concentrations in fishes of the Upper Colorado River Basin, southwestern United States: A retrospective assessment Mercury and selenium concentrations in fishes of the Upper Colorado River Basin, southwestern United States: A retrospective assessment
Mercury (Hg) and selenium (Se) are contaminants of concern for fish in the Upper Colorado River Basin (UCRB). We explored Hg and Se in fish tissues (2,324 individuals) collected over 50 years (1962–2011) from the UCRB. Samples include native and non-native fish collected from lotic waterbodies spanning 7 major tributaries to the Colorado River. There was little variation of total mercury...
Authors
Natalie K. Day, Travis Schmidt, James Roberts, Barbara C. Osmundson, James Willacker, Collin A. Eagles-Smith
Microsite enhancements for soil stabilization and rapid biocrust colonization in degraded drylands Microsite enhancements for soil stabilization and rapid biocrust colonization in degraded drylands
In dryland ecosystems, natural recovery of biological soil crusts (biocrusts) following disturbance may be slow or inhibited, necessitating active restoration practices. While biocrusts can be readily propagated under environmentally controlled conditions, rehabilitation in the field is complicated by environmental stresses which may be particularly acute in degraded, destabilized soils...
Authors
Stephen E. Fick, Natalie K. Day, Michael C. Duniway, Sean Lawrence Hoy-Skubik, Nichole N. Barger
Amendments fail to hasten biocrust recovery or soil stability at a disturbed dryland sandy site Amendments fail to hasten biocrust recovery or soil stability at a disturbed dryland sandy site
In most drylands, biological soil crusts (biocrusts), an assemblage of lichens, bryophytes, fungi, green algae, and cyanobacteria, are critical to healthy ecosystem function. However, they are extremely sensitive to disturbance and attempts to facilitate their recovery have had variable success. In this study, we applied soil amendments designed to improve soil surface stability and...
Authors
David G. Chandler, Natalie K. Day, Matthew D. Madsen, Jayne Belnap
Non-USGS Publications**
Jech, S.D., Dohrenwend, K., Day, N., Barger, N.N., Antoninka, A., Bowker, M.A., Reed, S., and Tucker, C., 2025, Developing biocrust field cultivation techniques for soil restoration: An assessment of bacterial communities: Applied Soil Ecology, v. 206, article 10586, https://doi.org/10.1016/j.apsoil.2024.105861.
Antoninka, A., Rowe, H., Weser, J., Langenfeld, D., Brady, J., Sprague, T., Day, N., 2024. Comparing greenhouse and field biocrust cultivation methods in the Sonoran Desert. Ecological Solutions and Evidence.
Jech, S.D., Day, N., Barger, N.N., Antoninka, A., Bowker, M.A., Reed, S., Tucker, C., 2023. Cultivating Resilience in Dryland Soils: An Assisted Migration Approach to Biological Soil Crust Restoration. Microorganisms Special Issue New Horizons in Terrestrial Cyanobacteria: Advancing Fundamental Understanding of Physiology, Ecology and Genomics.
Tillman, Fred D, Natalie K. Day, Matthew P. Miller, Olivia L. Miller, Christine A. Rumsey, Daniel R. Wise, Patrick C. Longley, and Morgan C. McDonnell. 2022. "A Review of Current Capabilities and Science Gaps in Water Supply Data, Modeling, and Trends for Water Availability Assessments in the Upper Colorado River Basin" Water 14, no. 23: 3813. https://doi.org/10.3390/w14233813
Sutfin, N.A., Wohl, E., Fegel, T., Day, N., Lynch, L., 2021. Logjams and Channel Morphology Influence Sediment Storage, Transformation of Organic Matter, and Carbon Storage Within Mountain Stream Corridors. Water resources research. v. 57(5), https://doi.org/10.1029/2020WR028046
Fick, S.E., Day, N., Duniway, M.C., Hoy‐Skubik, S. and Barger, N.N., 2019. Microsite enhancements for soil stabilization and rapid biocrust colonization in degraded drylands. Restoration Ecology.
Tucker, C., Antoninka, A., Day, N., Poff, B. and Reed, S., 2020. Biological soil crust salvage for dryland restoration: an opportunity for natural resource restoration. Restoration Ecology.
Amendments fail to hasten biocrust recovery or soil stability at a disturbed dryland sandy site
Day, N.K., Hall Jr, R.O. 2017. Ammonium uptake kinetics and nitrification in mountain streams. Freshwater Science v. 36.1, p. 41-54.
Day, N.K., Likens, G.E., Judd, K.E., 2006. Nitrogen cycling in streams: A comparison of the roles of debris dams and mosses. Institute of Ecosystem Studies.
**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
Assessment of Mercury and Selenium Accumulation in Upper Colorado River Basin Fish
More than 50 years of existing mercury and selenium concentrations in native and nonnative fish species residing in streams within the Upper Colorado River Basin were compiled and analyzed to provide an understanding of concentrations among different species, sampling years, and locations to determine potential health risks. Concentrations of mercury and selenium were above health benchmarks in 13...
Characterization of Streamflow, Suspended Sediment, and Nutrients in the Upper Yampa River Basin
The Upper Yampa River Basin (UYRB) drains approximately 1,800 square miles west of the Continental Divide in northwestern Colorado. In 2019, the USGS, in cooperation with local stakeholders in the UYRB water community, initiated a study to characterize streamflow, suspended sediment, and nutrients using historic and recently acquired water-quality data from a long-term monitoring program initiated...
Analyte concentrations and stable isotopes in fish tissue collected across the upper Colorado River Basin in 2016 and 2017 Analyte concentrations and stable isotopes in fish tissue collected across the upper Colorado River Basin in 2016 and 2017
These data were compiled to examine analyte concentrations, including mercury and selenium, and stable isotopes in native and non-native fish across rivers in the Upper Colorado River Basin. Data were collected in 2016 and 2017. Tissue samples were collected as whole-body or muscle plugs (biopsies). Tissue samples were analyzed for stable isotopes in 772 samples, for selenium and 54...
Long-term trends in annual, seasonal, and monthly streamflow metrics at streamgages in the Upper Colorado River Basin, 1981-2022 Long-term trends in annual, seasonal, and monthly streamflow metrics at streamgages in the Upper Colorado River Basin, 1981-2022
Identifying long-term trends in water availability, including surface water quantity, is a key part of the U.S. Geological Survey (USGS) Integrated Water Availability Assessments (IWAAs) mission. This data release includes input and output data used in Mann-Kendall trend analyses to characterize streamflow conditions at 124 USGS streamgages in the Upper Colorado River Basin for water...
Benthic algae community composition data from the Colorado River Basin, Colorado, from 2022-23 Benthic algae community composition data from the Colorado River Basin, Colorado, from 2022-23
This dataset includes benthic algae community composition data in the Colorado River near Cameo, Colorado, U.S. Geological Survey (USGS) site number 09095500, from 2022 to 2023, and from three sites in the upper White River Basin, Colorado, in 2022. Taxonomic classification of algae species is not known well in theses rivers, and this study was conducted to record different algae species...
Erosion rates and salinity and selenium yields in a basin near Rangely, Colorado following the 2017 Dead Dog wildfire as modeled by WEPP and measured from UAV Erosion rates and salinity and selenium yields in a basin near Rangely, Colorado following the 2017 Dead Dog wildfire as modeled by WEPP and measured from UAV
This data release accompanies a U.S Geological Survey study that assessed sediment, salinity, and selenium yields following the Dead Dog wildfire in northwestern Colorado. The Dead Dog fire ignited on June 11, 2017, near Rangely, Colorado, and burned over 17,000 acres, including the B2 study area. Two methodologies were used to quantify erosion and associated salinity and sediment yields...
Channel Characteristics, benthic algae, and water quality model data for selected sites in the upper White River Basin, Colorado, 2018-21 Channel Characteristics, benthic algae, and water quality model data for selected sites in the upper White River Basin, Colorado, 2018-21
This U.S. Geological Survey (USGS) data release provides benthic algae and stream channel characteristics data collected from 20 water-quality sites in the Upper White River Basin, Colorado., during 2018-2021. Also included are input and output data from streamflow and water-quality regression models used to characterize streamflow and water-quality conditions at 3 sites in the Upper...
Orthoimagery, digital elevation, digital terrain, final surface, and vegetation classification models for four stream catchments in western Colorado 2016 Orthoimagery, digital elevation, digital terrain, final surface, and vegetation classification models for four stream catchments in western Colorado 2016
Unmanned Aerial System (UAS) flights were conducted over four stream catchments in Rio Blanco County, Colorado, during the summer of 2016. Two sties had active oil and gas operations within the basin whereas the other two sites did not. Structure from motion (SfM) was used to align raw images and create a dense point cloud, georectified orthoimage, and Digital Elevation Model (DEM) for...
Input and output data from streamflow and water-quality regression models used to characterize streamflow and water-quality conditions in the Upper Yampa River Basin, Colorado, from 1992-2018 Input and output data from streamflow and water-quality regression models used to characterize streamflow and water-quality conditions in the Upper Yampa River Basin, Colorado, from 1992-2018
This dataset includes input and output data from streamflow and water-quality regression models used to characterize streamflow and water-quality conditions in the Upper Yampa River Basin, Colorado from 1999-2018. All input data, including discrete and continuous streamflows and discrete concentrations of suspended sediment, Kjeldahl nitrogen, and total phosphorus, were compiled from the...
Surrogate regression models for computation of time series suspended-sediment concentrations at Muddy Creek above Paonia Reservoir, Anthracite Creek above mouth near Somerset, and North Fork Gunnison below Raven Gulch near Somerset, Colorado Surrogate regression models for computation of time series suspended-sediment concentrations at Muddy Creek above Paonia Reservoir, Anthracite Creek above mouth near Somerset, and North Fork Gunnison below Raven Gulch near Somerset, Colorado
This model archive summary documents the surrogate regression model used to compute suspended-sediment concentrations at Muddy Creek above Paonia Reservoir, CO, USGS site number 385903107210800. The methods used follow U.S. Geological Survey (USGS) guidance as referenced in relevant Office of Surface Water Technical Memorandum (TM) 2016.07 and Office of Water Quality TM 2016.10, and USGS...
Fish tissue mercury and selenium concentrations in Upper Colorado River Basin: 1962-2011 Fish tissue mercury and selenium concentrations in Upper Colorado River Basin: 1962-2011
These data were compiled to study mercury and selenium concentrations in fish species and assemblages in lotic waterbodies across the Upper Colorado River Basin. Data were compiled from State and Federal agencies. This data table contains raw concentration data, as well as standardized concentrations corrected for differences based on sample type (i.e., tissue type), species-specific...
Salinity or sum of constituents— Methods comparison for computing dissolved solids concentrations in streams of the Upper Colorado River Basin Salinity or sum of constituents— Methods comparison for computing dissolved solids concentrations in streams of the Upper Colorado River Basin
The Colorado River is an important water source in the southwestern United States and northern Mexico. High concentrations of dissolved solids in the river, sourced mainly from the Upper Colorado River Basin (UCOL), cause hundreds of millions of dollars in damages annually to crops and infrastructure. Determinations of total dissolved solids (TDS) in river and tributary samples often...
Authors
Fred D. Tillman, Matthew P. Miller, Daniel Wise, R. Blaine McCleskey, Natalie K. Day
Wildland fire effects on sediment, salinity, and selenium yields in a basin underlain by Cretaceous marine shales near Rangely, Colorado Wildland fire effects on sediment, salinity, and selenium yields in a basin underlain by Cretaceous marine shales near Rangely, Colorado
Understanding and quantifying soil erosion from rangelands is a high priority for land managers, especially in areas underlain by Cretaceous Mancos Shale, which is a natural source of sediment, salinity, and selenium to surface waters in many areas of western Colorado and eastern Utah. The purpose of this report is to present the results of a U.S. Geological Survey study that assessed...
Authors
Natalie K. Day, Todd M. Preston, Patrick C. Longley
Investigation of potential factors controlling benthic algae in the upper White River Basin, Colorado, 2018–21 Investigation of potential factors controlling benthic algae in the upper White River Basin, Colorado, 2018–21
Nuisance levels of benthic filamentous green algae are becoming increasingly common in surface waters of Colorado and the western United States. In 2018 the U.S. Geological Survey began a study in cooperation with the White River and Douglas Creek Conservation Districts, Colorado River Basin Salinity Control Forum, and the Colorado River Water Conservation District to collect and analyze...
Authors
Natalie K. Day, Mark F. Henneberg
Potential factors controlling benthic algae in the upper White River Basin, Colorado, 2018–21 Potential factors controlling benthic algae in the upper White River Basin, Colorado, 2018–21
Nuisance levels of benthic algae are becoming increasingly common in surface waters of the western United States and can compromise aesthetic quality, limit recreational activities, block water infrastructure, and negatively affect aquatic life. In cooperation with the White River and Douglas Creek Conservation Districts, the Colorado River Basin Salinity Control Forum, and the Colorado...
Authors
Rachel G. Gidley, Natalie K. Day
Characterization of streamflow and nutrient occurrence in the upper White River Basin, Colorado, 1980–2020 Characterization of streamflow and nutrient occurrence in the upper White River Basin, Colorado, 1980–2020
In 2016, Colorado Parks and Wildlife identified filamentous algae collected from the main stem White River as Cladophora glomerata, a pervasive nuisance aquatic alga. Excessive levels of filamentous algae can compromise aesthetic quality, limit recreational activities, and have negative effects on aquatic life including strong fluctuations in dissolved oxygen levels and a reduction in...
Authors
Natalie K. Day
A review of current capabilities and science gaps in water supply data, modeling, and trends for water availability assessments in the Upper Colorado River Basin A review of current capabilities and science gaps in water supply data, modeling, and trends for water availability assessments in the Upper Colorado River Basin
The Colorado River is a critical water resource in the southwestern United States, supplying drinking water for 40 million people in the region and water for irrigation of 2.2 million hectares of land. Extended drought in the Upper Colorado River Basin (UCOL) and the prospect of a warmer climate in the future pose water availability challenges for those charged with managing the river...
Authors
Fred D. Tillman, Natalie K. Day, Matthew P. Miller, Olivia L. Miller, Christine A. Rumsey, Daniel Wise, Patrick C. Longley, Morgan C. McDonnell
Analysis of Escherichia coli, total recoverable iron, and dissolved selenium concentrations, loading, and identifying data gaps for selected 303(d) listed streams, Grand Valley, western Colorado, 1980–2018 Analysis of Escherichia coli, total recoverable iron, and dissolved selenium concentrations, loading, and identifying data gaps for selected 303(d) listed streams, Grand Valley, western Colorado, 1980–2018
Tributaries to the Colorado River in the Grand Valley in western Colorado (segment COLCLC13b) have been placed on the State of Colorado 303(d) list as impaired for Escherichia coli (E. coli), total recoverable iron, and dissolved selenium. The Colorado Department of Public Health and Environment Water Quality Control Division is required to develop total maximum daily loads for these...
Authors
Lisa D. Miller, Rachel G. Gidley, Natalie K. Day, Judith C. Thomas
Assessment of streamflow and water quality in the Upper Yampa River Basin, Colorado, 1992–2018 Assessment of streamflow and water quality in the Upper Yampa River Basin, Colorado, 1992–2018
The Upper Yampa River Basin drains approximately 2,100 square miles west of the Continental Divide in north-western Colorado. There is a growing need to understand potential changes in the quantity and quality of water resources as the basin is undergoing increasing land and water development to support growing municipal, industrial, and recreational needs. The U.S. Geological Survey, in...
Authors
Natalie K. Day
Mercury and selenium concentrations in fishes of the Upper Colorado River Basin, southwestern United States: A retrospective assessment Mercury and selenium concentrations in fishes of the Upper Colorado River Basin, southwestern United States: A retrospective assessment
Mercury (Hg) and selenium (Se) are contaminants of concern for fish in the Upper Colorado River Basin (UCRB). We explored Hg and Se in fish tissues (2,324 individuals) collected over 50 years (1962–2011) from the UCRB. Samples include native and non-native fish collected from lotic waterbodies spanning 7 major tributaries to the Colorado River. There was little variation of total mercury...
Authors
Natalie K. Day, Travis Schmidt, James Roberts, Barbara C. Osmundson, James Willacker, Collin A. Eagles-Smith
Microsite enhancements for soil stabilization and rapid biocrust colonization in degraded drylands Microsite enhancements for soil stabilization and rapid biocrust colonization in degraded drylands
In dryland ecosystems, natural recovery of biological soil crusts (biocrusts) following disturbance may be slow or inhibited, necessitating active restoration practices. While biocrusts can be readily propagated under environmentally controlled conditions, rehabilitation in the field is complicated by environmental stresses which may be particularly acute in degraded, destabilized soils...
Authors
Stephen E. Fick, Natalie K. Day, Michael C. Duniway, Sean Lawrence Hoy-Skubik, Nichole N. Barger
Amendments fail to hasten biocrust recovery or soil stability at a disturbed dryland sandy site Amendments fail to hasten biocrust recovery or soil stability at a disturbed dryland sandy site
In most drylands, biological soil crusts (biocrusts), an assemblage of lichens, bryophytes, fungi, green algae, and cyanobacteria, are critical to healthy ecosystem function. However, they are extremely sensitive to disturbance and attempts to facilitate their recovery have had variable success. In this study, we applied soil amendments designed to improve soil surface stability and...
Authors
David G. Chandler, Natalie K. Day, Matthew D. Madsen, Jayne Belnap
Non-USGS Publications**
Jech, S.D., Dohrenwend, K., Day, N., Barger, N.N., Antoninka, A., Bowker, M.A., Reed, S., and Tucker, C., 2025, Developing biocrust field cultivation techniques for soil restoration: An assessment of bacterial communities: Applied Soil Ecology, v. 206, article 10586, https://doi.org/10.1016/j.apsoil.2024.105861.
Antoninka, A., Rowe, H., Weser, J., Langenfeld, D., Brady, J., Sprague, T., Day, N., 2024. Comparing greenhouse and field biocrust cultivation methods in the Sonoran Desert. Ecological Solutions and Evidence.
Jech, S.D., Day, N., Barger, N.N., Antoninka, A., Bowker, M.A., Reed, S., Tucker, C., 2023. Cultivating Resilience in Dryland Soils: An Assisted Migration Approach to Biological Soil Crust Restoration. Microorganisms Special Issue New Horizons in Terrestrial Cyanobacteria: Advancing Fundamental Understanding of Physiology, Ecology and Genomics.
Tillman, Fred D, Natalie K. Day, Matthew P. Miller, Olivia L. Miller, Christine A. Rumsey, Daniel R. Wise, Patrick C. Longley, and Morgan C. McDonnell. 2022. "A Review of Current Capabilities and Science Gaps in Water Supply Data, Modeling, and Trends for Water Availability Assessments in the Upper Colorado River Basin" Water 14, no. 23: 3813. https://doi.org/10.3390/w14233813
Sutfin, N.A., Wohl, E., Fegel, T., Day, N., Lynch, L., 2021. Logjams and Channel Morphology Influence Sediment Storage, Transformation of Organic Matter, and Carbon Storage Within Mountain Stream Corridors. Water resources research. v. 57(5), https://doi.org/10.1029/2020WR028046
Fick, S.E., Day, N., Duniway, M.C., Hoy‐Skubik, S. and Barger, N.N., 2019. Microsite enhancements for soil stabilization and rapid biocrust colonization in degraded drylands. Restoration Ecology.
Tucker, C., Antoninka, A., Day, N., Poff, B. and Reed, S., 2020. Biological soil crust salvage for dryland restoration: an opportunity for natural resource restoration. Restoration Ecology.
Amendments fail to hasten biocrust recovery or soil stability at a disturbed dryland sandy site
Day, N.K., Hall Jr, R.O. 2017. Ammonium uptake kinetics and nitrification in mountain streams. Freshwater Science v. 36.1, p. 41-54.
Day, N.K., Likens, G.E., Judd, K.E., 2006. Nitrogen cycling in streams: A comparison of the roles of debris dams and mosses. Institute of Ecosystem Studies.
**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.