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.
High spatial resolution sensor-based surface water quality along 540 kilometers of the Illinois Waterway, 2022 and 2023 High spatial resolution sensor-based surface water quality along 540 kilometers of the Illinois Waterway, 2022 and 2023
In support of the U.S. Geological Survey (USGS)-Next Generation Water Observing System (NGWOS) program, water quality data were collected in 2022-2023 in the Illinois River Basin—the third USGS Integrated Water Science (IWS) basin. These data were collected to document spatial heterogeneity in water quality across seasons and hydrologic conditions and to improve predictions of carbon and...
Phosphorus, nitrogen, chloride, and suspended-sediment load estimates for the Great Lakes Restoration Initiative tributary monitoring network: Water years 2011–2023 Phosphorus, nitrogen, chloride, and suspended-sediment load estimates for the Great Lakes Restoration Initiative tributary monitoring network: Water years 2011–2023
Phosphorus, nitrogen, chloride, and suspended-sediment loads, in 24 U.S. tributaries of the Great Lakes, were estimated using U.S. Geological Survey (USGS) data from the Great Lakes Restoration Initiative (GLRI) monitoring program for the period Oct 2010 through Sept 2023 (USGS water years 2011-23). Specific water-quality constituents include total phosphorus, orthophosphate, particulate...
Laboratory Optical Measurements From Discrete Surface Water Samples Collected During Water Quality Mapping Campaigns on the Illinois Waterway and Chicago Area Waterway Systems Laboratory Optical Measurements From Discrete Surface Water Samples Collected During Water Quality Mapping Campaigns on the Illinois Waterway and Chicago Area Waterway Systems
Fluorescence and absorbance spectra were measured in discrete surface water samples collected during three sampling campaigns (Nov 2022, Mar/Apr 2023, Jul 2023) on the Illinois Waterway (IWW) and Chicago Area Waterway System (CAWS), which are the primary drainage of the Illinois River Basin (IRB). Water sampling was conducted concurrently with a boat-based water quality mapping effort...
Phosphorus, nitrogen, and suspended-sediment loads measured at the Great Lakes Restoration Initiative tributary monitoring network: Water years 2011–2020 Phosphorus, nitrogen, and suspended-sediment loads measured at the Great Lakes Restoration Initiative tributary monitoring network: Water years 2011–2020
Phosphorus, nitrogen, and suspended-sediment loads, in 24 U.S. tributaries of the Great Lakes, were calculated using U.S. Geological Survey (USGS) data from the Great Lakes Restoration Initiative (GLRI) monitoring program for the period Oct 2010 through Sept 2020 (USGS water years 2011–2020). Total phosphorus, orthophosphate, particulate phosphorus, total nitrogen, nitrate plus nitrite...
Per- and polyfluoroalkyl substances (PFAS) and pharmaceutical compound data from passive and sediment samples from 62 Great Lakes tributary sites collected in 2018 Per- and polyfluoroalkyl substances (PFAS) and pharmaceutical compound data from passive and sediment samples from 62 Great Lakes tributary sites collected in 2018
This dataset includes per-and polyfluoroalkyl substances (PFAS) and pharmaceuticals monitored at 62 sampling sites in tributaries of the Laurentian Great Lakes. Chemicals were evaluated in a sediment sample (PFAS only) and water concentrations were estimated using polar organic chemical integrative samplers (POCIS). Sediment samples were collected from the 62 sites in June and July 2018...
Pesticides and pesticide transformation product data from passive samplers deployed in 15 Great Lakes tributaries, 2016 Pesticides and pesticide transformation product data from passive samplers deployed in 15 Great Lakes tributaries, 2016
This dataset includes pesticides and pesticide transformation products in 15 tributaries of the Great Lakes. Pesticides were monitored using polar organic chemical integrative samplers (POCIS) to estimate concentrations in water following standard protocols (Alvarez, 2010) in June and July 2016. POCIS extracts were analyzed for 225 chemicals (USGS National Water Quality Laboratory...
Below are publications associated with this staff profile.
Filter Total Items: 24
Changes in phosphorus concentration and flux from 2011 to 2023 in major U.S. tributaries to the Laurentian Great Lakes Changes in phosphorus concentration and flux from 2011 to 2023 in major U.S. tributaries to the Laurentian Great Lakes
Reducing phosphorus (P) flux to the Great Lakes is critical for improving water quality and controlling eutrophication. We used 13 water years (2011–2023) of U.S. Geological Survey data from 24 major U.S. tributaries (representing 47% of the U.S. Great Lakes watershed area) to evaluate temporal changes in orthophosphate (PO4-P) and total P (TP) using Weighted Regressions on Time...
Authors
Dustin William Kincaid, Matthew W. Diebel, Erin E. Bertke, Donald B. Bonville, G. F. Koltun, Dale M. Robertson, Luke C. Loken
Per- and polyfluoroalkyl substances in surface water and sediment in Great Lakes tributaries and relations with watershed attributes Per- and polyfluoroalkyl substances in surface water and sediment in Great Lakes tributaries and relations with watershed attributes
Per- and polyfluoroalkyl substances (PFAS) are chemicals of emerging concern that potentially pose risks to human and environmental health. In May–Oct 2018, sediment and passively collected surface water samples were collected from 62 tributary sites of the Laurentian Great Lakes with site catchments spanning various land cover types. Discrete samples of sediment collected manually and...
Authors
Luke C. Loken, Steven R. Corsi, David A. Alvarez, Matthew A. Pronschinske, Peter L. Lenaker, Michelle A. Nott, Chen Zhang, Erin Mani, Gerald T. Ankley
Prioritizing chemicals of emerging concern in the Great Lakes Basin using covariance of chemical concentrations and diverse biological responses from a variety of species Prioritizing chemicals of emerging concern in the Great Lakes Basin using covariance of chemical concentrations and diverse biological responses from a variety of species
The Great Lakes Restoration Initiative aims to protect and restore the nation’s largest freshwater resource, in part, by furthering our understanding of the effects of contaminants of emerging concern (CECs) and chemical mixtures on aquatic and terrestrial organisms. To address this goal, an interagency team conducted field studies at sites along the Maumee River in Ohio, USA, in 2016...
Authors
Kelsey Vitense, Luke C. Loken, Erin C Maloney, Brett R. Blackwell, Timothy W. Collette, Steven R. Corsi, Christine M. Custer, Erik Davenport, Satomi Kohno, Stephanie E. Hummel
Potential for biological effects of per- and polyfluoroalkyl substances in Great Lakes tributaries and associations with land cover and wastewater effluent Potential for biological effects of per- and polyfluoroalkyl substances in Great Lakes tributaries and associations with land cover and wastewater effluent
Surface water concentrations of per- and polyfluoroalkyl substances (PFAS) and potential for resulting biological effects were estimated in a study using polar organic chemical integrative samplers (POCIS) from 60 tributary sites within 20 watersheds in the Great Lakes Basin in 2018. Sites represented a range of urban to agricultural, forested, and wetland land uses and included a...
Authors
Steven R. Corsi, Luke C. Loken, Gerald T. Ankley, David A. Alvarez, Daniel L. Villeneuve
Global methane emissions from rivers and streams Global methane emissions from rivers and streams
Methane (CH4) is a potent greenhouse gas and its concentrations have tripled in the atmosphere since the industrial revolution. There is evidence that global warming has increased CH4 emissions from freshwater ecosystems1,2, providing positive feedback to the global climate. Yet for rivers and streams, the controls and the magnitude of CH4 emissions remain highly uncertain3,4. Here we...
Authors
Gerard Rocher-Ros, Emily H. Stanley, Luke C. Loken, Nora J. Casson, Peter A. Raymond, Shaoda Liu, Giuseppe Amatulli, Ryan A. Sponseller
GRiMeDB: The Global River Database Methane Database of concentrations and fluxes GRiMeDB: The Global River Database Methane Database of concentrations and fluxes
Despite their small spatial extent, fluvial ecosystems play a significant role in processing and transporting carbon in aquatic networks, which results in substantial emission of methane (CH4) into the atmosphere. For this reason, considerable effort has been put into identifying patterns and drivers of CH4 concentrations in streams and rivers and estimating fluxes to the atmosphere...
Authors
Emily H. Stanley, Luke C. Loken, Nora J. Casson, Samantha K. Oliver, Ryan A. Sponseller, Marcus B. Wallin, Liwei Zhang, Gerard Rocher-Ros
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.
ToxMixtures: A package to explore toxicity due to chemical mixtures ToxMixtures: A package to explore toxicity due to chemical mixtures
The ToxMixtures R-package includes a set of functions to analyze, visualize, and organize measured chemical concentration data as it relates to chemical mixtures. ToxMixtures combines outputs from the R-package toxEval with open access sources on molecular biology to provide information on potential biological effects of chemicals detected in environmental matrices. To use ToxMixtures...
Science and Products
Below are data associated with this staff profile.
High spatial resolution sensor-based surface water quality along 540 kilometers of the Illinois Waterway, 2022 and 2023 High spatial resolution sensor-based surface water quality along 540 kilometers of the Illinois Waterway, 2022 and 2023
In support of the U.S. Geological Survey (USGS)-Next Generation Water Observing System (NGWOS) program, water quality data were collected in 2022-2023 in the Illinois River Basin—the third USGS Integrated Water Science (IWS) basin. These data were collected to document spatial heterogeneity in water quality across seasons and hydrologic conditions and to improve predictions of carbon and...
Phosphorus, nitrogen, chloride, and suspended-sediment load estimates for the Great Lakes Restoration Initiative tributary monitoring network: Water years 2011–2023 Phosphorus, nitrogen, chloride, and suspended-sediment load estimates for the Great Lakes Restoration Initiative tributary monitoring network: Water years 2011–2023
Phosphorus, nitrogen, chloride, and suspended-sediment loads, in 24 U.S. tributaries of the Great Lakes, were estimated using U.S. Geological Survey (USGS) data from the Great Lakes Restoration Initiative (GLRI) monitoring program for the period Oct 2010 through Sept 2023 (USGS water years 2011-23). Specific water-quality constituents include total phosphorus, orthophosphate, particulate...
Laboratory Optical Measurements From Discrete Surface Water Samples Collected During Water Quality Mapping Campaigns on the Illinois Waterway and Chicago Area Waterway Systems Laboratory Optical Measurements From Discrete Surface Water Samples Collected During Water Quality Mapping Campaigns on the Illinois Waterway and Chicago Area Waterway Systems
Fluorescence and absorbance spectra were measured in discrete surface water samples collected during three sampling campaigns (Nov 2022, Mar/Apr 2023, Jul 2023) on the Illinois Waterway (IWW) and Chicago Area Waterway System (CAWS), which are the primary drainage of the Illinois River Basin (IRB). Water sampling was conducted concurrently with a boat-based water quality mapping effort...
Phosphorus, nitrogen, and suspended-sediment loads measured at the Great Lakes Restoration Initiative tributary monitoring network: Water years 2011–2020 Phosphorus, nitrogen, and suspended-sediment loads measured at the Great Lakes Restoration Initiative tributary monitoring network: Water years 2011–2020
Phosphorus, nitrogen, and suspended-sediment loads, in 24 U.S. tributaries of the Great Lakes, were calculated using U.S. Geological Survey (USGS) data from the Great Lakes Restoration Initiative (GLRI) monitoring program for the period Oct 2010 through Sept 2020 (USGS water years 2011–2020). Total phosphorus, orthophosphate, particulate phosphorus, total nitrogen, nitrate plus nitrite...
Per- and polyfluoroalkyl substances (PFAS) and pharmaceutical compound data from passive and sediment samples from 62 Great Lakes tributary sites collected in 2018 Per- and polyfluoroalkyl substances (PFAS) and pharmaceutical compound data from passive and sediment samples from 62 Great Lakes tributary sites collected in 2018
This dataset includes per-and polyfluoroalkyl substances (PFAS) and pharmaceuticals monitored at 62 sampling sites in tributaries of the Laurentian Great Lakes. Chemicals were evaluated in a sediment sample (PFAS only) and water concentrations were estimated using polar organic chemical integrative samplers (POCIS). Sediment samples were collected from the 62 sites in June and July 2018...
Pesticides and pesticide transformation product data from passive samplers deployed in 15 Great Lakes tributaries, 2016 Pesticides and pesticide transformation product data from passive samplers deployed in 15 Great Lakes tributaries, 2016
This dataset includes pesticides and pesticide transformation products in 15 tributaries of the Great Lakes. Pesticides were monitored using polar organic chemical integrative samplers (POCIS) to estimate concentrations in water following standard protocols (Alvarez, 2010) in June and July 2016. POCIS extracts were analyzed for 225 chemicals (USGS National Water Quality Laboratory...
Below are publications associated with this staff profile.
Filter Total Items: 24
Changes in phosphorus concentration and flux from 2011 to 2023 in major U.S. tributaries to the Laurentian Great Lakes Changes in phosphorus concentration and flux from 2011 to 2023 in major U.S. tributaries to the Laurentian Great Lakes
Reducing phosphorus (P) flux to the Great Lakes is critical for improving water quality and controlling eutrophication. We used 13 water years (2011–2023) of U.S. Geological Survey data from 24 major U.S. tributaries (representing 47% of the U.S. Great Lakes watershed area) to evaluate temporal changes in orthophosphate (PO4-P) and total P (TP) using Weighted Regressions on Time...
Authors
Dustin William Kincaid, Matthew W. Diebel, Erin E. Bertke, Donald B. Bonville, G. F. Koltun, Dale M. Robertson, Luke C. Loken
Per- and polyfluoroalkyl substances in surface water and sediment in Great Lakes tributaries and relations with watershed attributes Per- and polyfluoroalkyl substances in surface water and sediment in Great Lakes tributaries and relations with watershed attributes
Per- and polyfluoroalkyl substances (PFAS) are chemicals of emerging concern that potentially pose risks to human and environmental health. In May–Oct 2018, sediment and passively collected surface water samples were collected from 62 tributary sites of the Laurentian Great Lakes with site catchments spanning various land cover types. Discrete samples of sediment collected manually and...
Authors
Luke C. Loken, Steven R. Corsi, David A. Alvarez, Matthew A. Pronschinske, Peter L. Lenaker, Michelle A. Nott, Chen Zhang, Erin Mani, Gerald T. Ankley
Prioritizing chemicals of emerging concern in the Great Lakes Basin using covariance of chemical concentrations and diverse biological responses from a variety of species Prioritizing chemicals of emerging concern in the Great Lakes Basin using covariance of chemical concentrations and diverse biological responses from a variety of species
The Great Lakes Restoration Initiative aims to protect and restore the nation’s largest freshwater resource, in part, by furthering our understanding of the effects of contaminants of emerging concern (CECs) and chemical mixtures on aquatic and terrestrial organisms. To address this goal, an interagency team conducted field studies at sites along the Maumee River in Ohio, USA, in 2016...
Authors
Kelsey Vitense, Luke C. Loken, Erin C Maloney, Brett R. Blackwell, Timothy W. Collette, Steven R. Corsi, Christine M. Custer, Erik Davenport, Satomi Kohno, Stephanie E. Hummel
Potential for biological effects of per- and polyfluoroalkyl substances in Great Lakes tributaries and associations with land cover and wastewater effluent Potential for biological effects of per- and polyfluoroalkyl substances in Great Lakes tributaries and associations with land cover and wastewater effluent
Surface water concentrations of per- and polyfluoroalkyl substances (PFAS) and potential for resulting biological effects were estimated in a study using polar organic chemical integrative samplers (POCIS) from 60 tributary sites within 20 watersheds in the Great Lakes Basin in 2018. Sites represented a range of urban to agricultural, forested, and wetland land uses and included a...
Authors
Steven R. Corsi, Luke C. Loken, Gerald T. Ankley, David A. Alvarez, Daniel L. Villeneuve
Global methane emissions from rivers and streams Global methane emissions from rivers and streams
Methane (CH4) is a potent greenhouse gas and its concentrations have tripled in the atmosphere since the industrial revolution. There is evidence that global warming has increased CH4 emissions from freshwater ecosystems1,2, providing positive feedback to the global climate. Yet for rivers and streams, the controls and the magnitude of CH4 emissions remain highly uncertain3,4. Here we...
Authors
Gerard Rocher-Ros, Emily H. Stanley, Luke C. Loken, Nora J. Casson, Peter A. Raymond, Shaoda Liu, Giuseppe Amatulli, Ryan A. Sponseller
GRiMeDB: The Global River Database Methane Database of concentrations and fluxes GRiMeDB: The Global River Database Methane Database of concentrations and fluxes
Despite their small spatial extent, fluvial ecosystems play a significant role in processing and transporting carbon in aquatic networks, which results in substantial emission of methane (CH4) into the atmosphere. For this reason, considerable effort has been put into identifying patterns and drivers of CH4 concentrations in streams and rivers and estimating fluxes to the atmosphere...
Authors
Emily H. Stanley, Luke C. Loken, Nora J. Casson, Samantha K. Oliver, Ryan A. Sponseller, Marcus B. Wallin, Liwei Zhang, Gerard Rocher-Ros
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.
ToxMixtures: A package to explore toxicity due to chemical mixtures ToxMixtures: A package to explore toxicity due to chemical mixtures
The ToxMixtures R-package includes a set of functions to analyze, visualize, and organize measured chemical concentration data as it relates to chemical mixtures. ToxMixtures combines outputs from the R-package toxEval with open access sources on molecular biology to provide information on potential biological effects of chemicals detected in environmental matrices. To use ToxMixtures...
*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