James J Roberts, PhD
James J Roberts is a Research Fisheries Biologist based in Huron, OH.
James has broad research expertise and investigates the ecological consequences of stressors like invasive species, climate change, and eutrophication for aquatic systems and specifically fish populations. There are three overall themes his research is split between (Invasive species, native fish ecology/conservation, and climate changes effects) which are all related to the conservation and management of aquatic species and systems.
Currently, he is investigating the movement, behavior, and habitat use of Grass Carp, an invasive species in the Great Lakes. He has also conducted research in the Laurentian Great Lakes examining the ecological consequences of seasonal hypolimnetic hypoxia, dead zones, in Lake Erie. Specifically, he studied the effects (behavioral, physiological, and inter-specific) of hypoxia on the benthic fish assemblage of Lake Erie, while focusing on yellow perch. Previously, James has explored the potential effects climate change may have on the persistence of Cutthroat Trout in stream and lake habitats throughout the Southern Rocky Mountain region."
Professional Experience
Research Fisheries Biologist, USGS 2020-present; Great Lakes Science Center
Fish Biologist, USGS 2015-2020; Colorado Water Science Center
Research Ecologist-Mendenhall Fellow, USGS 2012-2015; Fort Collins Science Center
Education and Certifications
Ph.D. University of Michigan
M.S. University of Wyoming
B.S. University of Michigan
Science and Products
Science pages by this scientist
Data releases by this scientist
Filter Total Items: 15
Grass Carp Movement and Capture Data from the Sandusky River, Lake Erie, Ohio, USA from 2020 to 2022 Grass Carp Movement and Capture Data from the Sandusky River, Lake Erie, Ohio, USA from 2020 to 2022
Data includes grass carp position and sampling data from 2020 to 2022. We used grass carp that were implanted with acoustic transmitters. The position data was generated in Fathom Position from receivers that composed several VEMCO Positioning Systems (VPS). We also queried the Great Lakes Acoustic Telemetry Observation Network (GLATOS) to obtain non-VPS position detections from...
Impacts of bird predation on the detection of acoustic telemetry tags in fish (ver. 2.0, September 2025) Impacts of bird predation on the detection of acoustic telemetry tags in fish (ver. 2.0, September 2025)
This data release contains the methodology and results of three field experiments performed in 2024 and 2025 to better understand how predation impacts detection efficiency of acoustic tags. The first experiment was a static approach focusing on how different tag types, tag power, depth, distance to passive receivers, and predation would affect detection efficiency and utilized both...
Hydroacoustic data from uncrewed surface vehicle (USV) overtakes in Lakes Huron and Michigan, 2021 Hydroacoustic data from uncrewed surface vehicle (USV) overtakes in Lakes Huron and Michigan, 2021
These data were derived from hydroacoustic data collected by uncrewed surface vehicles (USVs) and powered research vessels. The powered vessels overtook the USVs in Lakes Huron and Michigan to study fish avoidance of survey vessels during traditional acoustic surveys. The water column was divided into three depth groups (epilimnion, metalimnion, hypolimnion) for analysis. Each drone...
Fish assemblage data collected within Pictured Rocks National Lakeshore, Michigan Fish assemblage data collected within Pictured Rocks National Lakeshore, Michigan
Freshwater lake and stream fish data were collected as part of cooperative project between the U.S. Geological Survey and the U.S. National Park Service which began in 2021. Data was primarily collected from 22 sites within the Pictured Rocks National Lakeshore. The number of sites sampled each year as well as the types of data collected and sampling methods varied during each visit...
Dataset for temporal influences on selenium partitioning, trophic transfer, and exposure in a major U.S. river Dataset for temporal influences on selenium partitioning, trophic transfer, and exposure in a major U.S. river
The trace element selenium is an essential element with a narrow window between concentrations needed to support life and those that cause toxicity to egg laying organisms. Selenium bioaccumulation in aquatic organisms is primarily the result of trophic transfer through food webs and is poorly predicted by dissolved concentrations in freshwater bodies. To better understand the hydrologic...
Invertebrate community data from native trout lakes and streams in the Southern Rocky Mountains Invertebrate community data from native trout lakes and streams in the Southern Rocky Mountains
Native trout in the West suffer a high degree of vulnerability, as highlighted by cutthroat trout, a group of 14 subspecies, most of which have been petitioned for listing under the Endangered Species Act (ESA). In the Southern Rocky Mountains, greenback cutthroat trout (Oncorhynchus clarkii stomias; GBCT) are listed as threatened under the ESA, and few populations remain, in part...
Multimedia related to this scientist
Publications by this scientist
Filter Total Items: 42
Paired comparisons with quiet surface drones show evidence of fish behavioral response to motorized vessels during acoustic surveys in Lake Superior Paired comparisons with quiet surface drones show evidence of fish behavioral response to motorized vessels during acoustic surveys in Lake Superior
Acoustic surveys are important for fish stock assessments, but fish responses to survey vessels can bias acoustic estimates. We leveraged quiet uncrewed surface vessels (USVs) to characterize potential bias in acoustic surveys. Five conventional motorized ships overtook USVs from astern over 2 km transects at night in Lake Superior in 2022. We examined the difference in acoustic...
Authors
Thomas Evans, Lars Rudstam, Suresh Sethi, Daniel Yule, David Warner, Steve A. Farha, Andrew Barnard, Mark Dufour, Timothy O’Brien, Kayden Nasworthy, Ian Harding, Bradley Ray, Edmund J. Isaac, Joshua Blankenheim, Hannah Blair, James Watkins, Steven Senczyszyn, James Roberts, Peter C. Esselman
Silver Chub spawning confirmed in the Maumee River, a tributary of Lake Erie Silver Chub spawning confirmed in the Maumee River, a tributary of Lake Erie
Objective Biodiversity is declining due to invasive species and other factors that can affect individual species differently. Silver Chub Macrhybopsis storeriana are declining in their native range, and their conservation status in the Great Lakes ranges from secure to possibly extirpated. Lake Erie once supported a large Silver Chub population until it crashed in the 1950s. Additionally...
Authors
Ryan Brown, Christine Mayer, Nathan Thompson, Corbin Hilling, James Roberts, Catherine Richter
Capturing potential: Leveraging grass carp behavior Ctenopharyngodon idella for enhanced removal Capturing potential: Leveraging grass carp behavior Ctenopharyngodon idella for enhanced removal
Effective management of invasive species benefits from a comprehensive understanding of the species’ behavior and interactions with the invaded system. We investigated temporal dynamics of telemetry detections and the potential utility of a traitor approach for informing response efforts to the invasive grass carp (Ctenopharyngodon idella) population in the Sandusky River, a major...
Authors
Matthew Acre, Tyler Hessler, Sophia Bonjour, James Roberts, Scott Colborne, Travis O. Brenden, Lucas Nathan, Dustin Broaddus, Christopher Vandergoot, Christine Mayer, Song Qian, Robert D. Hunter, Ryan Brown, Robin Calfee
First documentation of grass carp spawning in Lake Erie’s Central Basin First documentation of grass carp spawning in Lake Erie’s Central Basin
Grass carp (Ctenopharyngodon idella) are non-indigenous to North America having been translocated to the United States in the 1960s as a potential non-chemical solution for nuisance aquatic vegetation. Reproductively viable grass carp now exist in many watersheds in the United States. In the Great Lakes basin, grass carp were first discovered in the 1980s with direct confirmation of...
Authors
Corbin Hilling, Adam Landry, James Roberts, Nathan Thompson, Cathy Richter, Ryan Brown, Christine Mayer, Song Qian
A proposed methodology for conducting threats assessments within the Great Lakes Coregonines restoration framework A proposed methodology for conducting threats assessments within the Great Lakes Coregonines restoration framework
This document serves to fulfill the Coregonine Threats Assessment Science Team’s charge of providing a written recommendation for a methodology to conduct threats assessments for Great Lakes coregonines within the Coregonine Restoration Framework (CRF). Through a series of team meetings that included presentations by experts on five candidate threats assessment frameworks followed by...
Authors
Andrew Honsey, David Smith, Charles Bronte, Andy Cook, D. Drake, Dimitry Gorsky, Timothy B. Johnson, Nicholas Mandrak, James Roberts, Shawn Sitar
Exploring the interior of Europa with the Europa Clipper Exploring the interior of Europa with the Europa Clipper
The Galileo mission to Jupiter revealed that Europa is an ocean world. The Galileo magnetometer experiment in particular provided strong evidence for a salty subsurface ocean beneath the ice shell, likely in contact with the rocky core. Within the ice shell and ocean, a number of tectonic and geodynamic processes may operate today or have operated at some point in the past, including...
Authors
James Roberts, William B. McKinnon, Catherine Elder, Gabriel Tobie, John Biersteker, Duncan Young, Ryan S. Park, Gregor Steinbrugge, Francis Nimmo, Samuel Howell, Julie C. Castillo-Rogez, Morgan Cable, Jacob Abrahams, Michael Bland, Chase Chivers, Corey Cochrane, Andrew Dombard, Carolyn Ernst, Antonio Genova, Christopher Gerekos, Christopher Glein, Camilla Harris, Hamish Hay, Paul Hayne, Matthew Hedman, Hauke Hussmann, Xianzhe Jia, Krishan Khurana, Walter Kiefer, Randolph Kirk, Margaret Kivelson, Justin Lawrence, Erin Leonard, Jonathan Lunine, Erwan Mazarico, Thomas McCord, Alfred McEwen, Carol Paty, Lynnae Quick, Carol Raymond, Kurt Retherford, Lorenz Roth, Abigail Rymer, Joachim Saur, Kirk Scanlan, Dustin Schroeder, David Senske, Wencheng Shao, Krista Soderlund, Elizabeth Spiers, Marshall Styczinski, Paolo Tortora, Steven Vance, Michaela Villarreal, Benjamin Weiss, Joseph Westlake, Paul Withers, Natalie Wolfenbarger, Bonnie Buratti, Haje Korth, Robert Pappalardo, Interior Group
Non-USGS Publications**
Isaak, D.J., C.C. Muhlfeld, A.S. Todd, R. Al-Chokhatchy, J.J. Roberts, K.D. Fausch, J.L. Kershner, and S.W. Hostetler. 2012 The past as prelude to the future: Retrospective assessments for anticipating future climate vulnerabilities of salmonid fishes in the Rocky Mountain West. Fisheries 37(12): 542-556.
Goto, D., K. Lindelof, D.L. Fanslow, S.A. Ludsin, J.J. Roberts, H.A. Vanderploeg, A.F. Wilson, and T.O. Höök. 2012. Indirect consequences of hypolimnetic hypoxia on
zooplankton growth in a large eutrophic lake. Aquatic Biology 16: 217-227.
zooplankton growth in a large eutrophic lake. Aquatic Biology 16: 217-227.
Roberts, J.J., P.A. Grecay, S.A. Ludsin, S.A. Pothoven, H.A. Vanderploeg, and T.O. Höök. 2012 Evidence of hypoxic foraging forays by yellow perch (Perca flavescens) and potential consequences for prey consumption. Freshwater Biology 57: 922-937.
Roberts, J.J., T.O. Hook, S.A. Ludsin, S.A. Pothoven, H.A. Vanderploeg, and S.B. Brandt. 2009. Effects of hypolimnetic hypoxia in Lake Erie's central basin on foraging and distribution of yellow perch. Journal of Experimental Marine Biology and Ecology. 131:S132-S142.
Roberts, J.J. and F.J. Rahel. 2008. Irrigation canals as sink habitat for trout and other fishes in a Wyoming drainage. Transactions of the American Fisheries Society. 137:951-961.
Roberts, J.J. and F.J. Rahel. 2005. Accuracy of aerial telemetry in fisheries studies. North American Journal of Fisheries Management. 25:660-666.
Roberts, J.J. 2010. The ecological consequences of hypoxia for yellow perch (Perca flavescens) in Lake Erie. Doctoral Dissertation. 181 pp.
**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 pages by this scientist
Data releases by this scientist
Filter Total Items: 15
Grass Carp Movement and Capture Data from the Sandusky River, Lake Erie, Ohio, USA from 2020 to 2022 Grass Carp Movement and Capture Data from the Sandusky River, Lake Erie, Ohio, USA from 2020 to 2022
Data includes grass carp position and sampling data from 2020 to 2022. We used grass carp that were implanted with acoustic transmitters. The position data was generated in Fathom Position from receivers that composed several VEMCO Positioning Systems (VPS). We also queried the Great Lakes Acoustic Telemetry Observation Network (GLATOS) to obtain non-VPS position detections from...
Impacts of bird predation on the detection of acoustic telemetry tags in fish (ver. 2.0, September 2025) Impacts of bird predation on the detection of acoustic telemetry tags in fish (ver. 2.0, September 2025)
This data release contains the methodology and results of three field experiments performed in 2024 and 2025 to better understand how predation impacts detection efficiency of acoustic tags. The first experiment was a static approach focusing on how different tag types, tag power, depth, distance to passive receivers, and predation would affect detection efficiency and utilized both...
Hydroacoustic data from uncrewed surface vehicle (USV) overtakes in Lakes Huron and Michigan, 2021 Hydroacoustic data from uncrewed surface vehicle (USV) overtakes in Lakes Huron and Michigan, 2021
These data were derived from hydroacoustic data collected by uncrewed surface vehicles (USVs) and powered research vessels. The powered vessels overtook the USVs in Lakes Huron and Michigan to study fish avoidance of survey vessels during traditional acoustic surveys. The water column was divided into three depth groups (epilimnion, metalimnion, hypolimnion) for analysis. Each drone...
Fish assemblage data collected within Pictured Rocks National Lakeshore, Michigan Fish assemblage data collected within Pictured Rocks National Lakeshore, Michigan
Freshwater lake and stream fish data were collected as part of cooperative project between the U.S. Geological Survey and the U.S. National Park Service which began in 2021. Data was primarily collected from 22 sites within the Pictured Rocks National Lakeshore. The number of sites sampled each year as well as the types of data collected and sampling methods varied during each visit...
Dataset for temporal influences on selenium partitioning, trophic transfer, and exposure in a major U.S. river Dataset for temporal influences on selenium partitioning, trophic transfer, and exposure in a major U.S. river
The trace element selenium is an essential element with a narrow window between concentrations needed to support life and those that cause toxicity to egg laying organisms. Selenium bioaccumulation in aquatic organisms is primarily the result of trophic transfer through food webs and is poorly predicted by dissolved concentrations in freshwater bodies. To better understand the hydrologic...
Invertebrate community data from native trout lakes and streams in the Southern Rocky Mountains Invertebrate community data from native trout lakes and streams in the Southern Rocky Mountains
Native trout in the West suffer a high degree of vulnerability, as highlighted by cutthroat trout, a group of 14 subspecies, most of which have been petitioned for listing under the Endangered Species Act (ESA). In the Southern Rocky Mountains, greenback cutthroat trout (Oncorhynchus clarkii stomias; GBCT) are listed as threatened under the ESA, and few populations remain, in part...
Multimedia related to this scientist
Publications by this scientist
Filter Total Items: 42
Paired comparisons with quiet surface drones show evidence of fish behavioral response to motorized vessels during acoustic surveys in Lake Superior Paired comparisons with quiet surface drones show evidence of fish behavioral response to motorized vessels during acoustic surveys in Lake Superior
Acoustic surveys are important for fish stock assessments, but fish responses to survey vessels can bias acoustic estimates. We leveraged quiet uncrewed surface vessels (USVs) to characterize potential bias in acoustic surveys. Five conventional motorized ships overtook USVs from astern over 2 km transects at night in Lake Superior in 2022. We examined the difference in acoustic...
Authors
Thomas Evans, Lars Rudstam, Suresh Sethi, Daniel Yule, David Warner, Steve A. Farha, Andrew Barnard, Mark Dufour, Timothy O’Brien, Kayden Nasworthy, Ian Harding, Bradley Ray, Edmund J. Isaac, Joshua Blankenheim, Hannah Blair, James Watkins, Steven Senczyszyn, James Roberts, Peter C. Esselman
Silver Chub spawning confirmed in the Maumee River, a tributary of Lake Erie Silver Chub spawning confirmed in the Maumee River, a tributary of Lake Erie
Objective Biodiversity is declining due to invasive species and other factors that can affect individual species differently. Silver Chub Macrhybopsis storeriana are declining in their native range, and their conservation status in the Great Lakes ranges from secure to possibly extirpated. Lake Erie once supported a large Silver Chub population until it crashed in the 1950s. Additionally...
Authors
Ryan Brown, Christine Mayer, Nathan Thompson, Corbin Hilling, James Roberts, Catherine Richter
Capturing potential: Leveraging grass carp behavior Ctenopharyngodon idella for enhanced removal Capturing potential: Leveraging grass carp behavior Ctenopharyngodon idella for enhanced removal
Effective management of invasive species benefits from a comprehensive understanding of the species’ behavior and interactions with the invaded system. We investigated temporal dynamics of telemetry detections and the potential utility of a traitor approach for informing response efforts to the invasive grass carp (Ctenopharyngodon idella) population in the Sandusky River, a major...
Authors
Matthew Acre, Tyler Hessler, Sophia Bonjour, James Roberts, Scott Colborne, Travis O. Brenden, Lucas Nathan, Dustin Broaddus, Christopher Vandergoot, Christine Mayer, Song Qian, Robert D. Hunter, Ryan Brown, Robin Calfee
First documentation of grass carp spawning in Lake Erie’s Central Basin First documentation of grass carp spawning in Lake Erie’s Central Basin
Grass carp (Ctenopharyngodon idella) are non-indigenous to North America having been translocated to the United States in the 1960s as a potential non-chemical solution for nuisance aquatic vegetation. Reproductively viable grass carp now exist in many watersheds in the United States. In the Great Lakes basin, grass carp were first discovered in the 1980s with direct confirmation of...
Authors
Corbin Hilling, Adam Landry, James Roberts, Nathan Thompson, Cathy Richter, Ryan Brown, Christine Mayer, Song Qian
A proposed methodology for conducting threats assessments within the Great Lakes Coregonines restoration framework A proposed methodology for conducting threats assessments within the Great Lakes Coregonines restoration framework
This document serves to fulfill the Coregonine Threats Assessment Science Team’s charge of providing a written recommendation for a methodology to conduct threats assessments for Great Lakes coregonines within the Coregonine Restoration Framework (CRF). Through a series of team meetings that included presentations by experts on five candidate threats assessment frameworks followed by...
Authors
Andrew Honsey, David Smith, Charles Bronte, Andy Cook, D. Drake, Dimitry Gorsky, Timothy B. Johnson, Nicholas Mandrak, James Roberts, Shawn Sitar
Exploring the interior of Europa with the Europa Clipper Exploring the interior of Europa with the Europa Clipper
The Galileo mission to Jupiter revealed that Europa is an ocean world. The Galileo magnetometer experiment in particular provided strong evidence for a salty subsurface ocean beneath the ice shell, likely in contact with the rocky core. Within the ice shell and ocean, a number of tectonic and geodynamic processes may operate today or have operated at some point in the past, including...
Authors
James Roberts, William B. McKinnon, Catherine Elder, Gabriel Tobie, John Biersteker, Duncan Young, Ryan S. Park, Gregor Steinbrugge, Francis Nimmo, Samuel Howell, Julie C. Castillo-Rogez, Morgan Cable, Jacob Abrahams, Michael Bland, Chase Chivers, Corey Cochrane, Andrew Dombard, Carolyn Ernst, Antonio Genova, Christopher Gerekos, Christopher Glein, Camilla Harris, Hamish Hay, Paul Hayne, Matthew Hedman, Hauke Hussmann, Xianzhe Jia, Krishan Khurana, Walter Kiefer, Randolph Kirk, Margaret Kivelson, Justin Lawrence, Erin Leonard, Jonathan Lunine, Erwan Mazarico, Thomas McCord, Alfred McEwen, Carol Paty, Lynnae Quick, Carol Raymond, Kurt Retherford, Lorenz Roth, Abigail Rymer, Joachim Saur, Kirk Scanlan, Dustin Schroeder, David Senske, Wencheng Shao, Krista Soderlund, Elizabeth Spiers, Marshall Styczinski, Paolo Tortora, Steven Vance, Michaela Villarreal, Benjamin Weiss, Joseph Westlake, Paul Withers, Natalie Wolfenbarger, Bonnie Buratti, Haje Korth, Robert Pappalardo, Interior Group
Non-USGS Publications**
Isaak, D.J., C.C. Muhlfeld, A.S. Todd, R. Al-Chokhatchy, J.J. Roberts, K.D. Fausch, J.L. Kershner, and S.W. Hostetler. 2012 The past as prelude to the future: Retrospective assessments for anticipating future climate vulnerabilities of salmonid fishes in the Rocky Mountain West. Fisheries 37(12): 542-556.
Goto, D., K. Lindelof, D.L. Fanslow, S.A. Ludsin, J.J. Roberts, H.A. Vanderploeg, A.F. Wilson, and T.O. Höök. 2012. Indirect consequences of hypolimnetic hypoxia on
zooplankton growth in a large eutrophic lake. Aquatic Biology 16: 217-227.
zooplankton growth in a large eutrophic lake. Aquatic Biology 16: 217-227.
Roberts, J.J., P.A. Grecay, S.A. Ludsin, S.A. Pothoven, H.A. Vanderploeg, and T.O. Höök. 2012 Evidence of hypoxic foraging forays by yellow perch (Perca flavescens) and potential consequences for prey consumption. Freshwater Biology 57: 922-937.
Roberts, J.J., T.O. Hook, S.A. Ludsin, S.A. Pothoven, H.A. Vanderploeg, and S.B. Brandt. 2009. Effects of hypolimnetic hypoxia in Lake Erie's central basin on foraging and distribution of yellow perch. Journal of Experimental Marine Biology and Ecology. 131:S132-S142.
Roberts, J.J. and F.J. Rahel. 2008. Irrigation canals as sink habitat for trout and other fishes in a Wyoming drainage. Transactions of the American Fisheries Society. 137:951-961.
Roberts, J.J. and F.J. Rahel. 2005. Accuracy of aerial telemetry in fisheries studies. North American Journal of Fisheries Management. 25:660-666.
Roberts, J.J. 2010. The ecological consequences of hypoxia for yellow perch (Perca flavescens) in Lake Erie. Doctoral Dissertation. 181 pp.
**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.