Botulism in Fish and Wildlife
More Information
The death of large numbers of fish and wildlife on the Great Lakes is not uncommon at certain times of the year. One cause of large-scale fish and bird die-offs is Type E botulism. Small-scale die-offs caused by botulism occur annually around the Great Lakes, with the last large-scale botulism-related die-off occurring in Lake Ontario in 2007.
According to public health agencies, no cases of human illness have been attributed to outbreaks of botulism in the Great Lakes.
Type E botulism toxin is produced by a bacterium (Clostridium botulinum) that naturally lives in lake bottom sediment as harmless spores. Little is known about the ecology of the bacterium, but under certain conditions – a rich nutrient source (such as a dead animal), a complete lack of oxygen, and an optimum temperature – the bacterium begins producing the toxin and the toxin enters the aquatic food chain, affecting fish and birds that eat fish or molluscs.
You can still harvest and eat fish and waterfowl from Ontario lakes
Health Canada and local health units advise that proper cooking and handling of food eliminates the botulism toxin. Make sure you cook all fish or waterfowl thoroughly. As always, the public should refrain from consuming sick or dying fish or waterfowl.
Keep your pets safe
Your pets could get botulism from eating the raw flesh of a contaminated bird or fish. As a precaution, make sure your pet does not eat dead fish or birds that have washed up on the shoreline.
To dispose of dead fish or birds along your shoreline
- You are responsible for disposing of dead birds and fish on your property.
- Bury them or dispose of them in the garbage.
- Wear rubber gloves or cover your hands with plastic bags while handling the carcasses, and dispose of the gloves or bags in the garbage.
- Wash your hands thoroughly with soap and water after handling the carcasses.
- Wash any tool that came into contact with the animal with a disinfectant.
Want to report dead or dying fish or waterfowl?
- Shoreline property owners and others who want to report dead or dying waterfowl may call the Canadian Cooperative Wildlife Health Centre toll-free at 1-866-673-4781.
- To report fish die-offs, call the Ministry of Natural Resources at 1-866-929-0994.
