Luke C Loken
Luke Loken is a Hydrologist with the Upper Midwest Water Science Center.
I am a hydrologist with the U.S. Geological Survey with a broad ecological background. My research focuses on hydrology and biogeochemistry in aquatic ecosystems at a range of ecological-scales. Some topics include: 1) The causes and consequences of spatial heterogeneity of water chemistry in lakes, rivers, and estuaries. 2) Drivers and patterns of ecosystem processes (metabolism, nutrient cycling, population dynamics). 3) The persistence of human-derived material (fertilizers, pesticides, chemicals) in river networks across landscapes.
Education and Certifications
Ph.D., Freshwater and Marine Sciences, University of Wisconsin-Madison, 2018
M.S., Freshwater and Marine Sciences, University of Wisconsin-Madison, 2014
B.S., Biology, University of Michigan, 2006
Affiliations and Memberships*
Center for Limnology (CFL) Affiliate
The Long-Term Ecological Research Network (LTER)
American Geophysical Union (AGU)
Association for the Sciences of Limnology and Oceanography (ASLO)
Society of Freshwater Sciences (SFS)
Science and Products
Below are data associated with this staff profile.
Nutrient Addition Experiment in the Sacramento River Deep Water Ship Channel Nutrient Addition Experiment in the Sacramento River Deep Water Ship Channel
Data were collected in the Sacramento River Deep Water Ship Channel (West Sacramento, CA) in support of a whole-ecosystem experiment investigating whether phytoplankton production and biomass would respond to nitrate additions, which could potentially be exported to food-limited regions in the Sacramento-San Joaquin Delta. The experiment was conducted from July 2 to September 18, 2019.
Soil physical, chemical, and biological data from edge-of-field agricultural water quality monitoring sites in Great Lakes States Soil physical, chemical, and biological data from edge-of-field agricultural water quality monitoring sites in Great Lakes States
Soil data were collected from catchments of USGS edge-of-field (EOF) monitoring sites in Great Lakes Restoration Initiative (GLRI) priority watersheds. As part of this release, soil data from 2016 through 2019 are provided from 14 sites spanning 5 Great Lake States (Wisconsin, Michigan, Ohio, Indiana, and New York). The data collected are from private farms representing a variety of...
Nutrient and sediment concentrations, loads, yields, and rainfall characteristics at USGS surface and subsurface-tile edge-of-field agricultural monitoring sites in Great Lakes States (ver. 3.0, November 2024) Nutrient and sediment concentrations, loads, yields, and rainfall characteristics at USGS surface and subsurface-tile edge-of-field agricultural monitoring sites in Great Lakes States (ver. 3.0, November 2024)
This data release focuses on nutrient and sediment concentrations, loads, and yields at USGS surface and subsurface-tile edge-of-field (EOF) agricultural monitoring sites in Great Lakes States. Water quality and rainfall metrics are summarized by individual flow events to evaluate the contribution of EOF losses to headwater stream networks in agricultural landscapes. USGS EOF sites are...
Below are publications associated with this staff profile.
Filter Total Items: 24
Assessment of conservation management practices on water quality and observed trends in the Plum Creek Basin, 2010–20 Assessment of conservation management practices on water quality and observed trends in the Plum Creek Basin, 2010–20
The U.S. Geological Survey and University of Wisconsin–Green Bay collected hydrologic and water-quality data to assess the effectiveness of agricultural conservation management practice (CMP) implementation at mainstem Plum Creek and west Plum Creek in northeastern Wisconsin. These two subbasins cover 88 percent of the Plum Creek Basin (Hydrologic Unit Code 12), which is a subbasin of...
Authors
Judy A. Horwatich, Kevin Fermanich, Matthew A. Pronschinske, Dale M. Robertson, Sarah Kussow, Luke C. Loken, Paul C. Reneau, Jeremy Freund, Matthew J. Komiskey
Hydrodynamics structure plankton communities and interactions in a freshwater tidal estuary Hydrodynamics structure plankton communities and interactions in a freshwater tidal estuary
Drivers of phytoplankton and zooplankton dynamics vary spatially and temporally in estuaries due to variation in hydrodynamic exchange and residence time, complicating efforts to understand controls on food web productivity. We conducted approximately monthly (2012–2019; n = 74) longitudinal sampling at 10 fixed stations along a freshwater tidal terminal channel in the San Francisco...
Authors
Adrianne P Smits, Luke C. Loken, Erwin E Van Nieuwenhuyse, Matthew J. Young, Paul Stumpner, Leah Kammel, Jon R. Burau, Randy A Dahlgren, Tiffany Brown, April Hennessey, Steven Sadro
Pesticide prioritization by potential biological effects in tributaries of the Laurentian Great Lakes Pesticide prioritization by potential biological effects in tributaries of the Laurentian Great Lakes
Watersheds of the Great Lakes Basin (USA/Canada) are highly modified and impacted by human activities including pesticide use. Despite labeling restrictions intended to minimize risks to nontarget organisms, concerns remain that environmental exposures to pesticides may be occurring at levels negatively impacting nontarget organisms. We used a combination of organismal-level toxicity...
Authors
Samantha K. Oliver, Steven R. Corsi, Austin K. Baldwin, Michelle A. Nott, Gerald T. Ankley, Brett R. Blackwell, Daniel L. Villeneuve, Michelle Hladik, Dana W. Kolpin, Luke C. Loken, Laura A. DeCicco, Michael T. Meyer, Keith A. Loftin
Prioritizing pesticides of potential concern and identifying potential mixture effects in Great Lakes tributaries using passive samplers Prioritizing pesticides of potential concern and identifying potential mixture effects in Great Lakes tributaries using passive samplers
To help meet the objectives of the Great Lakes Restoration Initiative with regard to increasing knowledge about toxic substances, 223 pesticides and pesticide transformation products were monitored in 15 Great Lakes tributaries using polar organic chemical integrative samplers. A screening-level assessment of their potential for biological effects was conducted by computing toxicity...
Authors
Luke C. Loken, Steven R. Corsi, David A. Alvarez, Gerald T. Ankley, Austin K. Baldwin, Bradley D. Blackwell, Laura A. DeCicco, Michelle A. Nott, Samantha K. Oliver, Daniel L. Villeneuve
Whole-ecosystem experiment illustrates short timescale hydrodynamic, light, and nutrient control of primary production in a terminal slough Whole-ecosystem experiment illustrates short timescale hydrodynamic, light, and nutrient control of primary production in a terminal slough
Estuaries are among the most productive of aquatic ecosystems. Yet the collective understanding of patterns and drivers of primary production in estuaries is incomplete, in part due to complex hydrodynamics and multiple controlling factors that vary at a range of temporal and spatial scales. A whole-ecosystem experiment was conducted in a deep, pelagically dominated terminal channel of...
Authors
Luke C. Loken, Steven Sadro, Leah Lenoch, Paul Stumpner, Randy A Dahlgren, Jon R. Burau, Erwin E Van Nieuwenhuyse
Challenges in linking soil health to edge-of-field water quality across the Great Lakes basin Challenges in linking soil health to edge-of-field water quality across the Great Lakes basin
To better understand agricultural nutrient losses, we evaluated relationships between management (e.g., manure and tillage), soil health measurements, and resulting edge-of-field (EOF) surface water quality. This work was conducted before or early into conservation implementation at 14 Great Lakes Restoration Initiative EOF sites spanning Wisconsin, Michigan, Indiana, Ohio, and New York...
Authors
Kevin Fermanich, Molly Meyers, Luke C. Loken, Marianne Bischoff-Gray, Ronald Turco, Karen Stahlhber, Lisa Duriancik, Mathew Dornbush, Matthew J. Komiskey
Non-USGS Publications**
Coyne, K. (2022), What You Think About How Soil and Water Health Connect May Be Wrong. CSA News, 67: 4-10. https://doi.org/10.1002/csan.20907
**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.
Below are software associated with this staff profile.
Science and Products
Below are data associated with this staff profile.
Nutrient Addition Experiment in the Sacramento River Deep Water Ship Channel Nutrient Addition Experiment in the Sacramento River Deep Water Ship Channel
Data were collected in the Sacramento River Deep Water Ship Channel (West Sacramento, CA) in support of a whole-ecosystem experiment investigating whether phytoplankton production and biomass would respond to nitrate additions, which could potentially be exported to food-limited regions in the Sacramento-San Joaquin Delta. The experiment was conducted from July 2 to September 18, 2019.
Soil physical, chemical, and biological data from edge-of-field agricultural water quality monitoring sites in Great Lakes States Soil physical, chemical, and biological data from edge-of-field agricultural water quality monitoring sites in Great Lakes States
Soil data were collected from catchments of USGS edge-of-field (EOF) monitoring sites in Great Lakes Restoration Initiative (GLRI) priority watersheds. As part of this release, soil data from 2016 through 2019 are provided from 14 sites spanning 5 Great Lake States (Wisconsin, Michigan, Ohio, Indiana, and New York). The data collected are from private farms representing a variety of...
Nutrient and sediment concentrations, loads, yields, and rainfall characteristics at USGS surface and subsurface-tile edge-of-field agricultural monitoring sites in Great Lakes States (ver. 3.0, November 2024) Nutrient and sediment concentrations, loads, yields, and rainfall characteristics at USGS surface and subsurface-tile edge-of-field agricultural monitoring sites in Great Lakes States (ver. 3.0, November 2024)
This data release focuses on nutrient and sediment concentrations, loads, and yields at USGS surface and subsurface-tile edge-of-field (EOF) agricultural monitoring sites in Great Lakes States. Water quality and rainfall metrics are summarized by individual flow events to evaluate the contribution of EOF losses to headwater stream networks in agricultural landscapes. USGS EOF sites are...
Below are publications associated with this staff profile.
Filter Total Items: 24
Assessment of conservation management practices on water quality and observed trends in the Plum Creek Basin, 2010–20 Assessment of conservation management practices on water quality and observed trends in the Plum Creek Basin, 2010–20
The U.S. Geological Survey and University of Wisconsin–Green Bay collected hydrologic and water-quality data to assess the effectiveness of agricultural conservation management practice (CMP) implementation at mainstem Plum Creek and west Plum Creek in northeastern Wisconsin. These two subbasins cover 88 percent of the Plum Creek Basin (Hydrologic Unit Code 12), which is a subbasin of...
Authors
Judy A. Horwatich, Kevin Fermanich, Matthew A. Pronschinske, Dale M. Robertson, Sarah Kussow, Luke C. Loken, Paul C. Reneau, Jeremy Freund, Matthew J. Komiskey
Hydrodynamics structure plankton communities and interactions in a freshwater tidal estuary Hydrodynamics structure plankton communities and interactions in a freshwater tidal estuary
Drivers of phytoplankton and zooplankton dynamics vary spatially and temporally in estuaries due to variation in hydrodynamic exchange and residence time, complicating efforts to understand controls on food web productivity. We conducted approximately monthly (2012–2019; n = 74) longitudinal sampling at 10 fixed stations along a freshwater tidal terminal channel in the San Francisco...
Authors
Adrianne P Smits, Luke C. Loken, Erwin E Van Nieuwenhuyse, Matthew J. Young, Paul Stumpner, Leah Kammel, Jon R. Burau, Randy A Dahlgren, Tiffany Brown, April Hennessey, Steven Sadro
Pesticide prioritization by potential biological effects in tributaries of the Laurentian Great Lakes Pesticide prioritization by potential biological effects in tributaries of the Laurentian Great Lakes
Watersheds of the Great Lakes Basin (USA/Canada) are highly modified and impacted by human activities including pesticide use. Despite labeling restrictions intended to minimize risks to nontarget organisms, concerns remain that environmental exposures to pesticides may be occurring at levels negatively impacting nontarget organisms. We used a combination of organismal-level toxicity...
Authors
Samantha K. Oliver, Steven R. Corsi, Austin K. Baldwin, Michelle A. Nott, Gerald T. Ankley, Brett R. Blackwell, Daniel L. Villeneuve, Michelle Hladik, Dana W. Kolpin, Luke C. Loken, Laura A. DeCicco, Michael T. Meyer, Keith A. Loftin
Prioritizing pesticides of potential concern and identifying potential mixture effects in Great Lakes tributaries using passive samplers Prioritizing pesticides of potential concern and identifying potential mixture effects in Great Lakes tributaries using passive samplers
To help meet the objectives of the Great Lakes Restoration Initiative with regard to increasing knowledge about toxic substances, 223 pesticides and pesticide transformation products were monitored in 15 Great Lakes tributaries using polar organic chemical integrative samplers. A screening-level assessment of their potential for biological effects was conducted by computing toxicity...
Authors
Luke C. Loken, Steven R. Corsi, David A. Alvarez, Gerald T. Ankley, Austin K. Baldwin, Bradley D. Blackwell, Laura A. DeCicco, Michelle A. Nott, Samantha K. Oliver, Daniel L. Villeneuve
Whole-ecosystem experiment illustrates short timescale hydrodynamic, light, and nutrient control of primary production in a terminal slough Whole-ecosystem experiment illustrates short timescale hydrodynamic, light, and nutrient control of primary production in a terminal slough
Estuaries are among the most productive of aquatic ecosystems. Yet the collective understanding of patterns and drivers of primary production in estuaries is incomplete, in part due to complex hydrodynamics and multiple controlling factors that vary at a range of temporal and spatial scales. A whole-ecosystem experiment was conducted in a deep, pelagically dominated terminal channel of...
Authors
Luke C. Loken, Steven Sadro, Leah Lenoch, Paul Stumpner, Randy A Dahlgren, Jon R. Burau, Erwin E Van Nieuwenhuyse
Challenges in linking soil health to edge-of-field water quality across the Great Lakes basin Challenges in linking soil health to edge-of-field water quality across the Great Lakes basin
To better understand agricultural nutrient losses, we evaluated relationships between management (e.g., manure and tillage), soil health measurements, and resulting edge-of-field (EOF) surface water quality. This work was conducted before or early into conservation implementation at 14 Great Lakes Restoration Initiative EOF sites spanning Wisconsin, Michigan, Indiana, Ohio, and New York...
Authors
Kevin Fermanich, Molly Meyers, Luke C. Loken, Marianne Bischoff-Gray, Ronald Turco, Karen Stahlhber, Lisa Duriancik, Mathew Dornbush, Matthew J. Komiskey
Non-USGS Publications**
Coyne, K. (2022), What You Think About How Soil and Water Health Connect May Be Wrong. CSA News, 67: 4-10. https://doi.org/10.1002/csan.20907
**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.
Below are software associated with this staff profile.
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government