Of the four species of Asian Carp, Grass carp is the most imminent threat to the Canadian waters of the Great Lakes. In the field season of 2023 alone, there were three confirmed captures of Grass Carp in Canadian waters:
- June 20th, 2023 – A Grass Carp was captured by Fisheries and Oceans Canada crews doing early detection surveillance in the Grand River near Dunville, ON. Lab testing found it to be sterile (unable to reproduce).
- July 4th, 2023 – DFO’s Asian Carp program was notified by MNRF’s Lake Ontario Management Unit of a commercial capture of a Grass Carp in the Bay of Quinte, approximately 17 km ENE of Picton, ON. The fish was found to be a fertile female. Response operations were initiated and after 5 days of searching, no additional Grass Carp were found.
- August 16th, 2023 – A Grass Carp was captured by a recreational angler in the Niagara River near Fort Erie, ON. Lab testing found it to be sterile (unable to reproduce).
On the U.S. side, researchers recently found evidence of natural reproduction in the Sandusky and Maumee rivers, both tributaries of Lake Erie on the U..S. side. However, there is still no evidence of an established population in Canadian waters and monitoring continues.
Why worry about Grass Carp?
Grass carp can eat 40% of their body weight a day in aquatic plants. They only digest about half of the plant material they consume each day and expel the remaining material, which pollutes the water and promotes algal blooms. These eating habits alter ecosystems by reducing food availability, shelter, and spawning areas for native fishes.
What you can do:
You can help stop Grass Carp from establishing in Canada when out on the water by learning how to identify Grass Carp and report all suspected sightings of suspected Grass Carp. In Ontario, you can report to the Invading Species Hotline (1-800-563-7711), the EDDMaps App (available for Apple and Android), or EDDMaps.org. Download the Grass Carp identification and reporting guide here.
