Brent Knights (Former Employee)
Science and Products
Filter Total Items: 47
Lock operations influence upstream passages of invasive and native fishes at a Mississippi River high-head dam
Asian carps continue to expand their range in North America, necessitating efforts to limit the spread and establishment of reproducing populations. Mississippi River Lock and Dam 19 is a high-head dam that represents a population ‘pinch-point’ as passage through the lock chamber is the only means by which fishes can complete upstream movement. As such, this location could be a pivotal control poi
Authors
Andrea K. Fritts, Brent C. Knights, Jessica C. Stanton, Amanda S. Milde, Jonathan M. Vallazza, Marybeth K. Brey, Sara J. Tripp, Thomas E. Devine, Wesley Sleeper, James T. Lamer, Kyle J. Mosel
USGS Illinois River monitoring and evaluation
Asian carp monitoring and contract removal will continue throughout the Upper Illinois Waterway system as needed for adaptive management to mitigate, control, and contain Asian carp. Compiling data from monitoring and removal efforts into a centralized database (Illinois River Catch Database application) facilitates data standardization, quality, accessibility, sharing, and analysis to aid in Asia
Authors
Travis J. Harrison, Kevin D. Hop, Enrika Hlavacek, Brent C. Knights
USGS real-time telemetry in support of management
No abstract available.
Authors
Brent C. Knights, Marybeth K. Brey, Douglas Appel, Travis J. Harrison, James J. Duncker
USGS telemetry database and analyses in support of SEAcarP
No abstract available.
Authors
Brent C. Knights, Marybeth K. Brey, Jessica C. Stanton, Travis J. Harrison, Timothy J. Fox, Enrika Hlavacek, James J. Duncker
USGS Illinois River catch database and visualization
No abstract available.
Authors
Enrika Hlavacek, Travis J. Harrison, Brent C. Knights, Marybeth K. Brey
USGS geospatial support for unified fishing method
No abstract available.
Authors
Kevin D. Hop, Andrew C. Strassman, Jonathan M. Vallazza, Brent C. Knights
Estimating the degree to which distance and temperature differences drive changes in fish community composition over time in the upper Mississippi River
Similarity in community composition declines as distance between locations increases, a phenomenon that has been observed in a wide variety of freshwater, marine and terrestrial ecosystems. One driver of the distance-similarity relationship is the presence of environmental gradients that alter the suitability of sites for particular species. Although some environmental gradients, such as geology
Authors
James H. Larson, Jonathan M. Vallazza, Brent C. Knights
Influence of a high-head dam as a dispersal barrier to fish community structure of the Upper Mississippi River
In river systems, high‐head dams may increase the distance‐decay of fish community similarity by creating nearly impermeable dispersal barriers to certain species from upstream reaches. Substantial evidence suggests that migratory species are impacted by dams, and most previous studies in stream/river networks have focused on small streams and headwaters. Here, we assess whether a high‐head dam (L
Authors
Rebekah L. Anderson, Cory A. Anderson, James H. Larson, Brent C. Knights, Jonathan M. Vallazza, Sean E. Jenkins, James T. Lamer
Development of a quantitative PCR method for screening ichthyoplankton samples for bigheaded carps
Monitoring ichthyoplankton is useful for identifying reproductive fronts and spawning locations of bigheaded carps (Hypophthalmichthys spp.). Unfortunately, sorting and identifying ichthyoplankton to monitor for bigheaded carp reproduction is time consuming and expensive. Traditional methods require frequent egg-larvae sampling, sorting of all samples to obtain presumptively identified bigheaded c
Authors
Andrea K. Fritts, Brent C. Knights, James H. Larson, Jon Amberg, Christopher M. Merkes, Tariq Tajjioui, Steven E. Butler, Matthew J. Diana, David H. Wahl, Michael J. Weber, John D. Waters
USGS geospatial support for unified fishing method
No abstract available.
Authors
Kevin D. Hop, Andrew C. Strassman, Jonathan M. Vallazza, Brent C. Knights
Evaluating potential effects of bigheaded carps on fatty acid profiles of multiple trophic levels in large rivers of the Midwest, USA
Recent work indicates that the establishment of bigheaded carps (Hypophthalmichthys spp.) in the United States has led to a reduction in condition of native planktivores and may detrimentally affect other trophic levels by altering the base of aquatic food webs. We used fatty acids to evaluate potential effects of bigheaded carps on taxa from multiple trophic levels in the Upper Mississippi, Illin
Authors
Andrea K. Fritts, Brent C. Knights, Toben LaFrancois, Jonathan M. Vallazza, Lynn A. Bartsch, Michelle R. Bartsch, William B. Richardson, Sean Bailey, Rebecca Kreiling, Byron Karns
Stable isotope comparison between mantle and foot tissues of two freshwater unionids: Implications for food web studies
Unionid mussels are a key taxon for stable isotope studies of aquatic food webs, often serving as the primary integrator of the pelagic baseline. Past isotope studies with mussels have commonly used either foot tissue or mantle tissue, but no study has yet to quantify the relation of both carbon and nitrogen isotopes between these two tissue sources. This makes it difficult to justify cross-study
Authors
Toben LaFrancois, Andrea K. Fritts, Brent C. Knights, Byron Karns
Science and Products
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Filter Total Items: 47
Lock operations influence upstream passages of invasive and native fishes at a Mississippi River high-head dam
Asian carps continue to expand their range in North America, necessitating efforts to limit the spread and establishment of reproducing populations. Mississippi River Lock and Dam 19 is a high-head dam that represents a population ‘pinch-point’ as passage through the lock chamber is the only means by which fishes can complete upstream movement. As such, this location could be a pivotal control poiAuthorsAndrea K. Fritts, Brent C. Knights, Jessica C. Stanton, Amanda S. Milde, Jonathan M. Vallazza, Marybeth K. Brey, Sara J. Tripp, Thomas E. Devine, Wesley Sleeper, James T. Lamer, Kyle J. MoselUSGS Illinois River monitoring and evaluation
Asian carp monitoring and contract removal will continue throughout the Upper Illinois Waterway system as needed for adaptive management to mitigate, control, and contain Asian carp. Compiling data from monitoring and removal efforts into a centralized database (Illinois River Catch Database application) facilitates data standardization, quality, accessibility, sharing, and analysis to aid in AsiaAuthorsTravis J. Harrison, Kevin D. Hop, Enrika Hlavacek, Brent C. KnightsUSGS real-time telemetry in support of management
No abstract available.AuthorsBrent C. Knights, Marybeth K. Brey, Douglas Appel, Travis J. Harrison, James J. DunckerUSGS telemetry database and analyses in support of SEAcarP
No abstract available.AuthorsBrent C. Knights, Marybeth K. Brey, Jessica C. Stanton, Travis J. Harrison, Timothy J. Fox, Enrika Hlavacek, James J. DunckerUSGS Illinois River catch database and visualization
No abstract available.AuthorsEnrika Hlavacek, Travis J. Harrison, Brent C. Knights, Marybeth K. BreyUSGS geospatial support for unified fishing method
No abstract available.AuthorsKevin D. Hop, Andrew C. Strassman, Jonathan M. Vallazza, Brent C. KnightsEstimating the degree to which distance and temperature differences drive changes in fish community composition over time in the upper Mississippi River
Similarity in community composition declines as distance between locations increases, a phenomenon that has been observed in a wide variety of freshwater, marine and terrestrial ecosystems. One driver of the distance-similarity relationship is the presence of environmental gradients that alter the suitability of sites for particular species. Although some environmental gradients, such as geologyAuthorsJames H. Larson, Jonathan M. Vallazza, Brent C. KnightsInfluence of a high-head dam as a dispersal barrier to fish community structure of the Upper Mississippi River
In river systems, high‐head dams may increase the distance‐decay of fish community similarity by creating nearly impermeable dispersal barriers to certain species from upstream reaches. Substantial evidence suggests that migratory species are impacted by dams, and most previous studies in stream/river networks have focused on small streams and headwaters. Here, we assess whether a high‐head dam (LAuthorsRebekah L. Anderson, Cory A. Anderson, James H. Larson, Brent C. Knights, Jonathan M. Vallazza, Sean E. Jenkins, James T. LamerDevelopment of a quantitative PCR method for screening ichthyoplankton samples for bigheaded carps
Monitoring ichthyoplankton is useful for identifying reproductive fronts and spawning locations of bigheaded carps (Hypophthalmichthys spp.). Unfortunately, sorting and identifying ichthyoplankton to monitor for bigheaded carp reproduction is time consuming and expensive. Traditional methods require frequent egg-larvae sampling, sorting of all samples to obtain presumptively identified bigheaded cAuthorsAndrea K. Fritts, Brent C. Knights, James H. Larson, Jon Amberg, Christopher M. Merkes, Tariq Tajjioui, Steven E. Butler, Matthew J. Diana, David H. Wahl, Michael J. Weber, John D. WatersUSGS geospatial support for unified fishing method
No abstract available.AuthorsKevin D. Hop, Andrew C. Strassman, Jonathan M. Vallazza, Brent C. KnightsEvaluating potential effects of bigheaded carps on fatty acid profiles of multiple trophic levels in large rivers of the Midwest, USA
Recent work indicates that the establishment of bigheaded carps (Hypophthalmichthys spp.) in the United States has led to a reduction in condition of native planktivores and may detrimentally affect other trophic levels by altering the base of aquatic food webs. We used fatty acids to evaluate potential effects of bigheaded carps on taxa from multiple trophic levels in the Upper Mississippi, IllinAuthorsAndrea K. Fritts, Brent C. Knights, Toben LaFrancois, Jonathan M. Vallazza, Lynn A. Bartsch, Michelle R. Bartsch, William B. Richardson, Sean Bailey, Rebecca Kreiling, Byron KarnsStable isotope comparison between mantle and foot tissues of two freshwater unionids: Implications for food web studies
Unionid mussels are a key taxon for stable isotope studies of aquatic food webs, often serving as the primary integrator of the pelagic baseline. Past isotope studies with mussels have commonly used either foot tissue or mantle tissue, but no study has yet to quantify the relation of both carbon and nitrogen isotopes between these two tissue sources. This makes it difficult to justify cross-studyAuthorsToben LaFrancois, Andrea K. Fritts, Brent C. Knights, Byron Karns