Patrick M Kocovsky
I am the Aquatic Invasive Species Program Manager within the Biological Threats and Invasive Species Research Program in the Ecosystems Mission Area.
I administer the USGS’ national research program on Aquatic Invasive Species. Our research foci include risk assessment, early detection and rapid response, and developing and evaluating deterrents and control methods for aquatic invasive species.
Education and Certifications
BS in Fishery Biology, magna cum laude, Colorado State, 1993
MS in Wildlife and Fisheries Science, Penn State, 1999
PhD in Wildlife and Fisheries Science, Penn State, 2004
Post-doc with USGS Northern Appalachian Research Lab on suitability of Susquehanna River tributaries for restoration of anadromous alosines and catadromous American Eel.
Science and Products
Filter Total Items: 13
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Modeling framework to estimate spawning and hatching locations of pelagically-spawned eggs
Identifying spawning and hatching locations is vital to controlling invasive fish and conserving imperiled fish, which can be difficult for pelagically-spawning species with semi-buoyant eggs. In freshwater systems, this reproductive strategy is common among cyprinid species, such as Chinese carp species currently threatening the Great Lakes. Following the confirmation that one of these species, G
Authors
Holly S. Embke, Patrick Kočovský, Tatiana Garcia, Christine M. Mayer, Song S. Qian
Diets of endangered silver chub (Macrhybopsis storeriana, Kirtland, 1844) in Lake Erie and implications for recovery
Silver chub (Macrhybopsis storeriana, Kirtland, 1844) is a native Cyprinid in Lake Erie, one of the Laurentian Great Lakes of North America. It is listed as endangered by the US state of New York and Canada, which has a recovery plan, and as special concern by the state of Michigan. Silver chub faces a potential threat to recovery from control efforts for invasive Grass carp (Ctenopharyngodon idel
Authors
Patrick Kočovský
Fish community responses to submerged aquatic vegetation in Maumee Bay, Western Lake Erie
Submerged aquatic vegetation (SAV) in clearwater systems simultaneously provides habitat for invertebrate prey and acts as refugia for small fishes. Many fishes in Lake Erie rely on shallow, heavily vegetated bays as spawning grounds and the loss or absence of which is known to reduce recruitment in other systems. The Maumee River and Maumee Bay, which once had abundant macrophyte beds, have exper
Authors
Jacob Miller, Patrick Kočovský, Daniel Wiegmann, Jeffery G. Miner
Inferred fish behavior its implications for hydroacoustic surveys in nearshore habitats
Population availability and vessel avoidance effects on hydroacoustic abundance estimates may be scale dependent; therefore, it is important to evaluate these biases across systems. We performed an inter-ship comparison survey to determine the effect of vessel size, day-night period, depth, and environmental gradients on walleye (Sander vitreus) density estimates in Lake Erie, an intermediate-scal
Authors
Mark R. DuFour, Christine M. Mayer, Song S. Qian, Christopher Vandergoot, Richard T. Kraus, Patrick Kočovský, David M. Warner
Water guns affect abundance and behavior of bigheaded carp and native fish differently
Water guns have shown the potential to repel nuisance aquatic organisms. This study examines the effects of exposure to a 1966.4 cm3 seismic water gun array (two guns) on the abundance and behavior of Bighead Carp Hypophthalmichthys nobilis, Silver Carp H. molitrix (collectively referred to as bigheaded carp) and native fishes (e.g., Smallmouth Buffalo Ictiobus bubalus). Water guns were deployed i
Authors
Jose Rivera, David C. Glover, Patrick Kočovský, James E. Garvey, Mark P. Gaikowski, Nathan R. Jensen, Ryan F. Adams
Evaluating factors driving population densities of mayfly nymphs in Western Lake Erie
Mayfly (Hexagenia spp.) nymphs have been widely used as indicators of water and substrate quality in lakes. Thermal stratification and the subsequent formation of benthic hypoxia may result in nymph mortality. Our goal was to identify potential associations between recent increases in temperature and eutrophication, which exacerbate hypoxic events in lakes, and mayfly populations in Lake Erie. Nym
Authors
Martin A. Stapanian, Patrick Kočovský, Betsy L. Bodamer Scarbro
An integral projection model with YY-males and application to evaluating grass carp control
Invasive fish species disrupt ecosystems and cause economic damage. Several methods have been discussed to control populations of invasive fish including the release of YY-males. YY-males are fish that have 2 male chromosomes compared to a XY-male. When YY-males mate, they only produce male (XY) offspring. This decreases the female proportion of the population and can, in theory, eradicate local p
Authors
Richard A. Erickson, Eric A. Eager, Marybeth K. Brey, Michael J. Hansen, Patrick Kočovský
Reconciling catch differences from multiple fishery independent gill net surveys
Fishery independent gill net surveys provide valuable demographic information for population assessment and resource management, but relative to net construction, the effects of ancillary species, and environmental variables on focal species catch rates are poorly understood. In response, we conducted comparative deployments with three unique, inter-agency, survey gill nets used to assess walleye
Authors
Richard T. Kraus, Christopher Vandergoot, Patrick M. Kocovsky, Mark W. Rogers, H. Andrew Cook, Travis O. Brenden
Sparse targets in hydroacoustic surveys: Balancing quantity and quality of in situ target strength data
Hydroacoustic sampling of low-density fish in shallow water can lead to low sample sizes of naturally variable target strength (TS) estimates, resulting in both sparse and variable data. Increasing maximum beam compensation (BC) beyond conventional values (i.e., 3 dB beam width) can recover more targets during data analysis; however, data quality decreases near the acoustic beam edges. We identifi
Authors
Mark R. DuFour, Christine M. Mayer, Patrick Kočovský, Song Qian, David M. Warner, Richard T. Kraus, Christopher Vandergoot
Fisheries research and monitoring activities of the Lake Erie Biological Station, 2016
We conducted a biomass-based assessment of the Lake Erie Western Basin fish community using data collected from 2013-2016 Western Basin (spring and autumn) bottom trawl surveys. Biomass of total catch per hectare has decreased 75 percent since 2013. Declines were observed across all functional groups, but most notable was the decline of Emerald Shiner, which decreased from 25.3 kg/ha in spring 201
Authors
Betsy L. Bodamer Scarbro, Richard T. Kraus, Patrick Kočovský, Christopher Vandergoot
First direct confirmation of grass carp spawning in a Great Lakes tributary
Grass carp (Ctenopharyngodon idella), an invasive species of Asian carp, has been stocked for many decades in the United States for vegetation control. Adult individuals have been found in all of the Great Lakes except Lake Superior, but no self-sustaining populations have yet been identified in Great Lakes tributaries. In 2012, a commercial fisherman caught four juvenile diploid grass carp in the
Authors
Holly S. Embke, Patrick M. Kocovsky, Catherine A. Richter, Jeremy J. Pritt, Christine M. Mayer, Song Qian
Developing fish trophic interaction indicators of climate change for the Great Lakes
This project addressed regional climate change effects on aquatic food webs in the Great Lakes. We sought insights by examining Lake Erie as a representative system with a high level of anthropogenic impacts, strong nutrient gradients, seasonal hypoxia, and spatial overlap of cold- and cool-water fish guilds. In Lake Erie and in large embayments throughout the Great Lakes basin, this situation is
Authors
Richard T. Kraus, Carey T. Knight, Ann Marie Gorman, Patrick M. Kocovsky, Brian C. Weidel, Mark W. Rogers
Science and Products
Filter Total Items: 13
No Result Found
Filter Total Items: 50
Modeling framework to estimate spawning and hatching locations of pelagically-spawned eggs
Identifying spawning and hatching locations is vital to controlling invasive fish and conserving imperiled fish, which can be difficult for pelagically-spawning species with semi-buoyant eggs. In freshwater systems, this reproductive strategy is common among cyprinid species, such as Chinese carp species currently threatening the Great Lakes. Following the confirmation that one of these species, G
Authors
Holly S. Embke, Patrick Kočovský, Tatiana Garcia, Christine M. Mayer, Song S. Qian
Diets of endangered silver chub (Macrhybopsis storeriana, Kirtland, 1844) in Lake Erie and implications for recovery
Silver chub (Macrhybopsis storeriana, Kirtland, 1844) is a native Cyprinid in Lake Erie, one of the Laurentian Great Lakes of North America. It is listed as endangered by the US state of New York and Canada, which has a recovery plan, and as special concern by the state of Michigan. Silver chub faces a potential threat to recovery from control efforts for invasive Grass carp (Ctenopharyngodon idel
Authors
Patrick Kočovský
Fish community responses to submerged aquatic vegetation in Maumee Bay, Western Lake Erie
Submerged aquatic vegetation (SAV) in clearwater systems simultaneously provides habitat for invertebrate prey and acts as refugia for small fishes. Many fishes in Lake Erie rely on shallow, heavily vegetated bays as spawning grounds and the loss or absence of which is known to reduce recruitment in other systems. The Maumee River and Maumee Bay, which once had abundant macrophyte beds, have exper
Authors
Jacob Miller, Patrick Kočovský, Daniel Wiegmann, Jeffery G. Miner
Inferred fish behavior its implications for hydroacoustic surveys in nearshore habitats
Population availability and vessel avoidance effects on hydroacoustic abundance estimates may be scale dependent; therefore, it is important to evaluate these biases across systems. We performed an inter-ship comparison survey to determine the effect of vessel size, day-night period, depth, and environmental gradients on walleye (Sander vitreus) density estimates in Lake Erie, an intermediate-scal
Authors
Mark R. DuFour, Christine M. Mayer, Song S. Qian, Christopher Vandergoot, Richard T. Kraus, Patrick Kočovský, David M. Warner
Water guns affect abundance and behavior of bigheaded carp and native fish differently
Water guns have shown the potential to repel nuisance aquatic organisms. This study examines the effects of exposure to a 1966.4 cm3 seismic water gun array (two guns) on the abundance and behavior of Bighead Carp Hypophthalmichthys nobilis, Silver Carp H. molitrix (collectively referred to as bigheaded carp) and native fishes (e.g., Smallmouth Buffalo Ictiobus bubalus). Water guns were deployed i
Authors
Jose Rivera, David C. Glover, Patrick Kočovský, James E. Garvey, Mark P. Gaikowski, Nathan R. Jensen, Ryan F. Adams
Evaluating factors driving population densities of mayfly nymphs in Western Lake Erie
Mayfly (Hexagenia spp.) nymphs have been widely used as indicators of water and substrate quality in lakes. Thermal stratification and the subsequent formation of benthic hypoxia may result in nymph mortality. Our goal was to identify potential associations between recent increases in temperature and eutrophication, which exacerbate hypoxic events in lakes, and mayfly populations in Lake Erie. Nym
Authors
Martin A. Stapanian, Patrick Kočovský, Betsy L. Bodamer Scarbro
An integral projection model with YY-males and application to evaluating grass carp control
Invasive fish species disrupt ecosystems and cause economic damage. Several methods have been discussed to control populations of invasive fish including the release of YY-males. YY-males are fish that have 2 male chromosomes compared to a XY-male. When YY-males mate, they only produce male (XY) offspring. This decreases the female proportion of the population and can, in theory, eradicate local p
Authors
Richard A. Erickson, Eric A. Eager, Marybeth K. Brey, Michael J. Hansen, Patrick Kočovský
Reconciling catch differences from multiple fishery independent gill net surveys
Fishery independent gill net surveys provide valuable demographic information for population assessment and resource management, but relative to net construction, the effects of ancillary species, and environmental variables on focal species catch rates are poorly understood. In response, we conducted comparative deployments with three unique, inter-agency, survey gill nets used to assess walleye
Authors
Richard T. Kraus, Christopher Vandergoot, Patrick M. Kocovsky, Mark W. Rogers, H. Andrew Cook, Travis O. Brenden
Sparse targets in hydroacoustic surveys: Balancing quantity and quality of in situ target strength data
Hydroacoustic sampling of low-density fish in shallow water can lead to low sample sizes of naturally variable target strength (TS) estimates, resulting in both sparse and variable data. Increasing maximum beam compensation (BC) beyond conventional values (i.e., 3 dB beam width) can recover more targets during data analysis; however, data quality decreases near the acoustic beam edges. We identifi
Authors
Mark R. DuFour, Christine M. Mayer, Patrick Kočovský, Song Qian, David M. Warner, Richard T. Kraus, Christopher Vandergoot
Fisheries research and monitoring activities of the Lake Erie Biological Station, 2016
We conducted a biomass-based assessment of the Lake Erie Western Basin fish community using data collected from 2013-2016 Western Basin (spring and autumn) bottom trawl surveys. Biomass of total catch per hectare has decreased 75 percent since 2013. Declines were observed across all functional groups, but most notable was the decline of Emerald Shiner, which decreased from 25.3 kg/ha in spring 201
Authors
Betsy L. Bodamer Scarbro, Richard T. Kraus, Patrick Kočovský, Christopher Vandergoot
First direct confirmation of grass carp spawning in a Great Lakes tributary
Grass carp (Ctenopharyngodon idella), an invasive species of Asian carp, has been stocked for many decades in the United States for vegetation control. Adult individuals have been found in all of the Great Lakes except Lake Superior, but no self-sustaining populations have yet been identified in Great Lakes tributaries. In 2012, a commercial fisherman caught four juvenile diploid grass carp in the
Authors
Holly S. Embke, Patrick M. Kocovsky, Catherine A. Richter, Jeremy J. Pritt, Christine M. Mayer, Song Qian
Developing fish trophic interaction indicators of climate change for the Great Lakes
This project addressed regional climate change effects on aquatic food webs in the Great Lakes. We sought insights by examining Lake Erie as a representative system with a high level of anthropogenic impacts, strong nutrient gradients, seasonal hypoxia, and spatial overlap of cold- and cool-water fish guilds. In Lake Erie and in large embayments throughout the Great Lakes basin, this situation is
Authors
Richard T. Kraus, Carey T. Knight, Ann Marie Gorman, Patrick M. Kocovsky, Brian C. Weidel, Mark W. Rogers