On Wednesday, May 16, the Michigan Department of Natural Resources, Fisheries Division received an anonymous photo report indicating the presence of grass carp in Marrs Lake in Lenawee County.
Fisheries Division is investigating this report. Grass carp are a prohibited species as defined in the Natural Resources and Environmental Protection Act 451 of 1994, Section 324.41301 and are illegal to possess, sell or stock live in Michigan.
Grass carp are considered an Asian carp species and, while they do not pose the same risk to Michigan’s waters as bighead or silver carp, they are of concern as they eat beneficial types of aquatic plants and alter good fish habitat.
Grass carp have been rarely found in Michigan waters. Previous cases usually were a result of illegal stocking in Michigan ponds or movements from other states where stocking genetically altered triploid fish for aquatic vegetation control is allowed. Other states allow the stocking of triploid fish because they believe the fish have a low probability of reproduction; however, the sterilization process is not 100-percent effective. Given their potential negative effects on good fish habitat, the Michigan Department of Natural Resources strongly opposes the use of triploid fish in both public and private waters.
The state of Michigan’s Asian Carp Management Plan outlines a goal to gather information from waters where grass carp have been detected. An assessment is planned for Marrs Lake, June 18–21, to determine if grass carp are present. If they are found, an analysis will be conducted to determine if these fish are reproducing naturally. Should grass carp be present, a Grass Carp Management Plan for Marrs Lake will be developed after the assessment results are analyzed.
Fisheries Division has been communicating with the waterfront residents of Marrs Lake for assistance on this matter and will continue to closely coordinate with them.
For more information on grass carp, visit www.michigan.gov/fishid and click on Asian Carp.