USGS Great Lakes Science Center technician Jared Lesniewicz processes an ichthyoplankton sample during a survey assessing grass carp spawning in the Cuyahoga River, a Lake Erie tributary in Cleveland, Ohio. As of the 2024 sampling season, no grass carp spawning has been documented in the Cuyahoga River. Photo Credit: James Roberts, USGS.
Identifying Spawning Tributaries and Specific Spawning Areas of Grass Carp
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By Great Lakes Science Center
February 7, 2025
Grass carp (Ctenopharyngodon idella) is an invasive species translocated to the United States in the 1960s due to its potential for nuisance aquatic vegetation control. Following escapes, authorized stockings, and unauthorized stockings, the grass carp range rapidly expanded in the U.S.
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Adult grass carp were first observed in the Great Lakes Basin in the 1980s, but perceived risks were low until 2012 when juveniles that were likely spawned in the wild were collected in the Sandusky River, a Lake Erie tributary. Since 2014, scientists with the U. S. Geological Survey and University of Toledo have studied grass carp reproductive ecology and early life history to inform grass carp management actions.
Scientists have documented grass carp spawning during or following high flow events from May to August in three Lake Erie tributaries, including the Sandusky, Maumee, and Huron rivers in Ohio. By gathering grass carp eggs and newly hatched fish, called larvae, scientists have been able to predict specific locations where grass carp spawn, the timing of their spawning, and locations where they hatch. As a result, fishery managers have been able to improve grass carp capture rates during removal efforts and estimates of hatching locations has improved scientists’ understanding of the risks of egg and larval survival. U.S. Geological Survey scientists work closely with agency and university partners through the Grass Carp Advisory Committee (GCAC), an advisory committee to the Great Lakes Fishery Commission, to develop research that addresses knowledge gaps to directly inform management of this invasive species.
This study is an on-going collaboration with the Great Lakes Fishery Commission, Ohio Department of Natural Resources Division of Wildlife, Michigan Department of Natural Resources, University of Toledo, U.S. Fish and Wildlife Service Alpena Fish and Wildlife Conservation Office, USGS Central Midwest Water Science Center, USGS Columbia Environmental Research Center, and USGS Ohio-Kentucky-Indiana Water Science Center.
Images related to this science project
Sampling at an Elevated Railroad Bridge
USGS Great Lakes Science Center technician Jared Lesniewicz processes an ichthyoplankton sample during a survey assessing grass carp spawning in the Cuyahoga River, a Lake Erie tributary in Cleveland, Ohio. As of the 2024 sampling season, no grass carp spawning has been documented in the Cuyahoga River. Photo Credit: James Roberts, USGS.
Grass Carp Eggs
An ichthyoplankton net sample within a collection bucket from the Sandusky River in May of 2022. Grass carp (Ctenopharyngodon idella) eggs are pictured in the foreground (semi-transparent spheres). Photo Credit: James Roberts, USGS
An ichthyoplankton net sample within a collection bucket from the Sandusky River in May of 2022. Grass carp (Ctenopharyngodon idella) eggs are pictured in the foreground (semi-transparent spheres). Photo Credit: James Roberts, USGS
Tracking the Movement of Grass Carp in the Sandusky River, 2016
Nicole King (University of Toledo graduate student) holding a Grass Carp. The Ohio Department of Natural Resources and Michigan State University responded to a report from a commercial fisherman that grass carp were being captured in the Sandusky River. Researchers captured, tagged, and released grass carp to track their movements.
Nicole King (University of Toledo graduate student) holding a Grass Carp. The Ohio Department of Natural Resources and Michigan State University responded to a report from a commercial fisherman that grass carp were being captured in the Sandusky River. Researchers captured, tagged, and released grass carp to track their movements.
Grass Carp Eggs Under a Microscope
Grass Carp Eggs being examined under a microscope to determine developmental stage.
Grass Carp Eggs being examined under a microscope to determine developmental stage.
Grass carp (Ctenopharyngodon idella) is an invasive species translocated to the United States in the 1960s due to its potential for nuisance aquatic vegetation control. Following escapes, authorized stockings, and unauthorized stockings, the grass carp range rapidly expanded in the U.S.
Media
Sources/Usage: Public Domain. View Media Details
Adult grass carp were first observed in the Great Lakes Basin in the 1980s, but perceived risks were low until 2012 when juveniles that were likely spawned in the wild were collected in the Sandusky River, a Lake Erie tributary. Since 2014, scientists with the U. S. Geological Survey and University of Toledo have studied grass carp reproductive ecology and early life history to inform grass carp management actions.
Scientists have documented grass carp spawning during or following high flow events from May to August in three Lake Erie tributaries, including the Sandusky, Maumee, and Huron rivers in Ohio. By gathering grass carp eggs and newly hatched fish, called larvae, scientists have been able to predict specific locations where grass carp spawn, the timing of their spawning, and locations where they hatch. As a result, fishery managers have been able to improve grass carp capture rates during removal efforts and estimates of hatching locations has improved scientists’ understanding of the risks of egg and larval survival. U.S. Geological Survey scientists work closely with agency and university partners through the Grass Carp Advisory Committee (GCAC), an advisory committee to the Great Lakes Fishery Commission, to develop research that addresses knowledge gaps to directly inform management of this invasive species.
This study is an on-going collaboration with the Great Lakes Fishery Commission, Ohio Department of Natural Resources Division of Wildlife, Michigan Department of Natural Resources, University of Toledo, U.S. Fish and Wildlife Service Alpena Fish and Wildlife Conservation Office, USGS Central Midwest Water Science Center, USGS Columbia Environmental Research Center, and USGS Ohio-Kentucky-Indiana Water Science Center.
Images related to this science project
Sampling at an Elevated Railroad Bridge
USGS Great Lakes Science Center technician Jared Lesniewicz processes an ichthyoplankton sample during a survey assessing grass carp spawning in the Cuyahoga River, a Lake Erie tributary in Cleveland, Ohio. As of the 2024 sampling season, no grass carp spawning has been documented in the Cuyahoga River. Photo Credit: James Roberts, USGS.
USGS Great Lakes Science Center technician Jared Lesniewicz processes an ichthyoplankton sample during a survey assessing grass carp spawning in the Cuyahoga River, a Lake Erie tributary in Cleveland, Ohio. As of the 2024 sampling season, no grass carp spawning has been documented in the Cuyahoga River. Photo Credit: James Roberts, USGS.
Grass Carp Eggs
An ichthyoplankton net sample within a collection bucket from the Sandusky River in May of 2022. Grass carp (Ctenopharyngodon idella) eggs are pictured in the foreground (semi-transparent spheres). Photo Credit: James Roberts, USGS
An ichthyoplankton net sample within a collection bucket from the Sandusky River in May of 2022. Grass carp (Ctenopharyngodon idella) eggs are pictured in the foreground (semi-transparent spheres). Photo Credit: James Roberts, USGS
Tracking the Movement of Grass Carp in the Sandusky River, 2016
Nicole King (University of Toledo graduate student) holding a Grass Carp. The Ohio Department of Natural Resources and Michigan State University responded to a report from a commercial fisherman that grass carp were being captured in the Sandusky River. Researchers captured, tagged, and released grass carp to track their movements.
Nicole King (University of Toledo graduate student) holding a Grass Carp. The Ohio Department of Natural Resources and Michigan State University responded to a report from a commercial fisherman that grass carp were being captured in the Sandusky River. Researchers captured, tagged, and released grass carp to track their movements.
Grass Carp Eggs Under a Microscope
Grass Carp Eggs being examined under a microscope to determine developmental stage.
Grass Carp Eggs being examined under a microscope to determine developmental stage.