Patrick M Kocovsky
My main research focus in on invasive species, primarily spawning and recruitment of Grass Carp in Lake Erie and potential control measures. I also study biology, taxonomy, and recovery of Silver Chub, a native and imperiled species with similar spawning requirements as Grass Carp. I also conduct hydroacoustics research in support of fisheries monitoring and management.
Biography
Education:
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.
I am a fish ecologist and invasive species specialist within Ecosystems Mission Area. My role is coordinating research and development of technologies in support of management and control of the four major Chinese carps (commonly referred to as “Asian carps”) in north America. I am also adjunct research faculty in the Department of Environmental Sciences at the University of Toledo, where I serve on numerous graduate academic committees.
Science and Products
Grass Carp in Lake Erie
Grass Carp, commonly used in aquaculture to control plant growth, escaped captivity in the Mississippi River and have been in the Great Lakes since 1975. Spawning surveys have documented spawning since 2015 in the Sandusky River leading to expanded surveys and an effort to confine reproduction to the western part of Lake Erie.
Asian Carp Integrated Control and Containment: Development of Monitoring and Response Methodologies, and Implementation of an Adaptive Management Framework to Work Towards Eradication of Grass Carp in Lake Erie
The US Geological Survey is studying life history and habitats of invasive Grass Carp with a goal of developing strategies and tactics to greatly reduce or possibly eradicate Grass Carp from Lake Erie.
Understanding How Climate Change will Impact Aquatic Food Webs in 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...
Water Chemistry of Great Lakes Tributaries, 2017-2018
Chemical composition of fish bones can be used to trace fish migrations and other movements (e.g., use of tributaries for spawning). Chemical composition of water is required to be able to trace fish migrations or movements to particular rivers or streams. Because water chemistry can change over time due to changes in land use, tectonic movements that alter groundwater pathways, polluti
Developmental Stages of Grass Carp (Ctenopharyngodon idella) eggs in the Sandusky River
Grass Carp Ctenopharyngodon idella was imported to the United States in the 1960s for research into its usefulness as a biocontrol agent for nuisance aquatic vegetation. Escapees and intentionally stocked individuals founded wild, spawning populations in the Mississippi River and tributaries to the Laurentian Great Lakes. USGS-led research on the Sandusky River, a tributary to Lake Erie, de...
Developmental Stages of Grass Carp (Ctenopharyngodon idella) eggs in the Sandusky River in 2017
Grass Carp Ctenopharyngodon idella was imported to the United States in the 1960s for research into its usefulness as a biocontrol agent for nuisance aquatic vegetation. Escapees and intentionally stocked individuals founded wild, spawning populations in the Mississippi River and tributaries to the Laurentian Great Lakes. USGS-led research on the Sandusky River, a tributary to Lake Erie, de...
Stable Isotopes of Silver Chub, Dreissenid mussels, and Hexagenia spp. Mayflies from Western Lake Erie, 2014
This table contains Carbon and Nitrogen stable isotope data for Silver Chub (Macrhybopsis storeriana), dreissenid mussels, and Hexagenia spp. mayflies from western Lake Erie in 2014. Samples were collected between May and September 2014 as part of both routine monitoring and a lake-wide coordinated monitoring effort. Silver Chub were collected in trawls; Hexagenia and Dreissenids were c
Diets of Silver Chub (Macrhybopsis storeriana) in western Lake Erie, 2014
Diet and estimated ages of Silver Chub (Macrhybopsis storeriana) collected by the US Geological Survey in western Lake Erie in 2014 are presented. Fish were frozen in the field at -20 C and dissected in the lab. Ages were estimated by one experienced biologist who estimated ages twice, then reconciled age estimates when the two age estimates differed. Diet taxa were enumerated, dried indi
Densities of Hexagenia mayfly nymphs in western Lake Erie, 1999-2014
Densities of Hexagenia spp. mayfly nymphs by age class are presented from 1999 through 2014. This range is significant in that it includes the year of peak abundance following recovery from ~4 decades of near extirpation (~1960 through the mid-1990s) through a period of decline. This range overlaps with fluctuations in abundance of other potentially relevant species, such as Round Goby
Status of the major aquaculture carps of China in the Laurentian Great Lakes Basin
There is concern of economic and environmental damage occuring if any of the four major aquacultured carp species of China, black carp Mylopharyngodon piceus, bighead carp Hypophthalmichthys nobilis, silver carp H. molitrix, or grass carp Ctenopharyngodon idella, were to establish in the Laurentian Great Lakes. All four are...
Chapman, Duane C.; Benscoter, Allison; Embke, Holly S.; King, Nicole R.; Kocovsky, Patrick; Lewis, Teresa D.; Mandrak, Nicholas E. Validation of the model-predicted spawning area of grass carp Ctenopharyngodon idella in the Sandusky River
Spawning of grass carp, Ctenopharyngodon idella, in the Great Lakes basin was verified when eight fertilized eggs were collected in the Sandusky River, a tributary to Lake Erie, in 2015. Using a fluvial drift model (FluEgg) and simulation modeling, researchers predicted the fertilization location for those eggs was 3.8 ± 1...
Kocovsky, Patrick; King, Nicole R.; Weimer, Eric; Mayer, Christine; Qian, Song S. Habitat characterization and species distribution model of the only large-lake population of the endangered Silver Chub (Macrhybopsis storeriana, Kirtland 1844)
The endangered Silver Chub (Macrhybopsis storeriana, Kirtland 1844) is native to North America and primarily riverine, with the only known large‐lake population in Lake Erie. Once a major component of the Lake Erie fish community, it declined and became nearly extirpated in the mid‐1900s. Recent collections in western Lake Erie suggest that...
McKenna, James E.; Kocovsky, Patrick Ethical guidelines for publication of fisheries research
In 2000, the Governing Board of the American Fisheries Society (AFS) approved the first Guidelines for Authorship (GFA) in AFS publications, developed by the AFS Publications Overview Committee (POC) chaired by Mary Fabrizio. This version of the GFA document provided guidance for fisheries science publications for nearly two decades. The 2015 AFS...
Kocovsky, Patrick; Gaunt, Patricia S; Peoples, Brandon K.; Frimpong, Emmanuel A Optimum electrofishing waveforms and parameters to induce a capture-prone response in juvenile Grass Carp
Grass Carp (Ctenopharyngodon idella) are a non-native species to North America that were first introduced for vegetation control in the 1960s. However, wild-reproducing Grass Carp can negatively impact aquatic habitats and aquatic communities by consuming substantial amounts of aquatic vegetation and increasing turbidity. Numerous fisheries...
Briggs, Andrew S; Dean, Jan C.; Boase, James C.; Kocovsky, Patrick; Luoma, James A. 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....
Embke, Holly S.; Kocovsky, Patrick; Garcia, Tatiana; Mayer, Christine M.; Qian, Song S. 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...
Kocovsky, Patrick Fisheries research and monitoring activities of the Lake Erie Biological Station, 2017
This report presents biomass-based summaries of fish communities in western Lake Erie derived from USGS bottom trawl surveys from 2013 to 2017 during June and September. The survey design provided temporal and spatial coverage that does not exist in the interagency trawl database, and thus complemented the August Ohio-Ontario effort to reinforce...
Keretz, Kevin R.; Kocovsky, Patrick; Kraus, Richard T.; Vandergoot, Christopher A spatially discrete, integral projection model and its application to invasive carp
Natural resource managers and ecologists often desire an understanding of spatial dynamics such as migration, dispersion, and meta-population dynamics. Network-node models can capture these salient features. Additionally, the state-variable used with many species may be appropriately modeled as a continuous variable (e.g., length) and...
Erickson, Richard A.; Eager, Eric E.; Kocovsky, Patrick; Glover, David C.; Kallis, Jahn L.; Long, K. R. What it is to be established: policy and management implications for non-native and invasive species
Management of invasive species, whether prevention, population reduction, or eradication, requires assessment of the invasive species’ population status and an assessment of the probability of success of management options. Perceptions of a species’ permanence in an environment or lack thereof frequently drives how limited time, financial, and...
Kocovsky, Patrick; Sturtevant, Rochelle; Schardt, James “Asian carp” is societally and scientifically problematic. Let's replace it
Bighead Carp Hypophthalmichthys nobilis, Black Carp Mylopharyngodon piceus, Grass Carp Ctenopharyngodon idella, and Silver Carp H. molitrix are considered invasive species in North America and Europe. In North America, they are typically referred to collectively as “Asian carp”, a reference to their native range. The...
Kocovsky, Patrick; Chapman, Duane C.; Qian, Song S. 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,...
Miller, Jacob; Kocovsky, Patrick; Wiegmann, Daniel; Miner, Jeffery G.
DNA Confirms Baby Grass Carp Threat to Lake Erie in Ohio River
Patrick Kocovsky discussed the confirmation, using DNA, of juvenile Grass Carp in the Maumee River
Grass Carp Larvae Found in Maumee River
Patrick Kocovsky interviewed about the discover of Grass Carp in the Maumee River
Ohio Department of Natural Resources Prepare to Search Sandusky River for Grass Carp
The Fremont News Messenger covered the preparations made by ODNR and its partners, including USGS, in this 2017 article.
Fremont News Messenger Covers USGS Collaboration in the Search for Grass Carp in Lake Erie Tributary
The Fremont News Messenger published a story about collaborative search for the invasive Grass Carp in the Sandusky River during the 2017 field season.
Patrick Kocovsky Interviewed by Michigan Radio NPR
Patrick Kocovsky Answers Grass Carp Qestions on Michigan Radio in 2016
Patrick Kocovsky Quoted by WTVG Channel 13 Toledo After Collection of Grass Carp Eggs
ABC News in Toledo covered a story about the discovery and collection of Grass Carp eggs in the Sandusky River. Dr. Patrick Kocovsky is quoted in the article from 2016.
Patrick Kocovsky Teaches Junior High Students About Fish Age Estimation
Passing on our knowledge to the next generation of scientists.
Patrick Kocovsky Participates in Press Forum with Representative Joyce on Asian Carp in Lake Erie
Communicating Invasive Species Issues with Congress.
Newly Hatched Invasive Grass Carp Found in Maumee River, Ohio
A genetic analysis conducted by the U.S. Geological Survey recently confirmed that larval, or newly hatched, fish collected from the Maumee River during the summer of 2018 are grass carp, one species of invasive Asian carps that threaten the Great Lakes. The Maumee River is a tributary to Lake Erie.