Protecting Lake Huron's fish

Posted: Friday, September 1, 2023
A file photo of Lake Huron.

The July 2023 incidences of dead fish along Lake Huron's shoreline and along the Ausable River are a concern to the public and a concern for everyone working to protect Lake Huron's fish species.

We all need to be part of the solution when it comes to responding to a threat, to our water and to our species, like this one.

One way to protect our needed fish species is to further implement the Ausable River Action Plan.

Speak with your local conservation organizations about nature-based solutions you can implement on your property and in your community.

We need to limit harmful impacts on fish and other aquatic species. 

We need to slow water down and allow it to soak into the ground so it doesn’t run off the landscape.

We are working with many partners and are creating projects which are helping ... but we need to do more.

“We need to continue to do more work to protect the habitat these fish need and to reduce the potential for harmful impacts,” said Kari Jean, Ausable Bayfield Conservation Authority (ABCA)  Aquatic Biologist.

It is also important to continue to monitor the populations of aquatic species, such as fish and the globally imperiled freshwater mussels, in the local watershed and we need to collect and compare data year over year. This makes it possible to better understand the extent of impacts of events like the fish die-off in July 2023 and to understand the actions needed to reduce the potential for more incidents like this one.

To learn more about the Ausable River Action Plan, and the work needed to monitor and to protect fish species in this nationally important river, you may visit the Ausable River web page.

Healthy Waters, Healthy Fish presentation in Port Franks on August 25, 2023

Ausable Bayfield Conservation and researchers from University of Toronto Scarborough hosted an information session, called Healthy Waters, Healthy Fish, at Port Franks Community Centre on Friday, August 25, 2023.

The presentation was held to provide information to concerned residents after a large number of dead fish, of different species, were reported over several kilometres of Lake Huron shoreline and along the Ausable River in July.

More than 60 people attended the session and it was clear that residents continued to be concerned about this event, its impact on our fish, and about preventing future events like this one.

The presenters provided information about the fish die-off, which affected at least eleven species of fish, and about proposed community-wide and multi-agency actions needed to help protect Lake Huron's fish species.

Here are the minutes of the meeting:

Mari Veliz, Healthy Watersheds Manager with Ausable Bayfield Conservation Authority (ABCA), spoke on fish species in the Ausable River. She spoke to a number of issues including habitat loss, invasive species and pollution.

She spoke of chronic threats (e.g., loss of habitat; nutrients and sediment) and acute threats (e.g., chemical spills; low dissolved oxygen levels; temperature). 

She also spoke of the roles of local watershed managers in facilitating local work to address chronic long-term threats and the role of Ontario environment and natural resources ministries in responding to acute threats.

The presenter underlined the need for comprehensive ACTions (Avoid; Control; Trap and Treat) to address chronic threats to our fish species. She spoke to solutions that can work in a working landscape. She also spoke of the need to link land and lake so positive improvements are made inland to reduce potential impacts on Lake Huron downstream.

She spoke of a suite of positive actions that are taking place and also the need for further, increased implementation of action plans that are in place.

The speaker thanked the public for making the protection of aquatic species a priority and for their efforts communicating with local agencies and Ontario ministries. She also provided some recommended actions people can take, on their own properties and in their community, to manage the volume of water running off of land during storm events and to protect native species.

Biologist Jennifer Powell is a PhD student at the University of Toronto Scarborough. She has conducted aquatic and fisheries assessments as a consultant and has been part of a team studying endangered fish in the Lambton Shores area since 2021. She spoke at the meeting and shared details of the fish die-off. Based on the wide extent of the fish die-off, she shared that the cause of the event is " ... likely to have been more complex than a single-source contaminant ..."

She said there were at least eleven different species of fish that were found. "The number of different species involved in this fish kill is an indication that this was unlikely to have been caused by a disease or pathogen as those typically only affect one species or a group of related species at a time," she told the meeting.

She also spoke about the need to reduce the number and extent of stressors affecting Lake Huron's fish populations.

"We can’t control the weather, but we can improve the overall quality of the river by identifying the stressors that are having the largest negative impact and then taking steps to remove them," she said. "Removing the stressors will improve the overall resiliency of the fishes and give them the best chance of survival if and when these kind of conditions happen again."

Details about fish die-off in Lake Huron and Ausable River in July 2023

Local residents reported dead fish in Lake Huron and Ausable River in July. Sometimes, when there is a die-off of fish of a single species, the cause may be a virus affecting that species. In the July occurrence of dead fish, there were die-offs of fish of several species.

Staff members of the Ontario Ministry of the Environment, Conservation and Parks (MECP) responded to the reports of dead fish in July and attended sites, where dead fish were found, to investigate possible causes of the fish die-offs. 

An Ausable Bayfield Conservation Authority (ABCA) staff member also visited several sites and provided local information and expertise in support of the Ministry investigation. 

“We appreciate the concern shown by our watershed residents and the reports they provided, to the Ministry and to us, through phone calls and emails,” said Kari Jean, ABCA Aquatic Biologist.

It’s a concern for everyone when an occurrence like this happens, she said. Incidences like this underline some of the issues that need to be addressed to prevent and reduce incidences like these and to limit the impacts on freshwater fish species including species at risk. 

Ministry assessment of July 2023 fish die-off along Lake Huron

The Ontario Ministry of the Environment, Conservation and Parks (MECP)  completed its assessment of the July 2023 die-off of fish along Lake Huron and the Ausable River.

The results of that assessment were shared in a local agency presentation at the August 25, 2023 fish presentation in Port Franks.

The Ministry staff, in their assessment, said they did not identify any spills or other sources of contaminants that could have contributed to the die-off. 

The Ministry found that dead fish were located both along the shores of Lake Huron and in the Ausable River. 

The Ministry consulted with other agencies. 

Based on how widespread the fish die-off was, the Ministry assessment determined that " ... the die-off is likely the result of naturally occurring conditions."

In a fish die-off, or fish kill, the death of fish may result from a virus or a single point source such a chemical spill or it can occur as a result of a number of factors. 

Some factors which can affect fish populations include low oxygen, temperature and weather fluctuations, sediment and runoff, among others. 

The Ministry invites the public to help identify pollution incidents when they happen. You may report urgent pollution incidents by phone at 1-866-MOE-TIPS (663-8477), 24 hours a day, seven days a week.

If you witness any of the following you are asked to report:

  • Pollution spilled on land, in the water or air
  •  Industrial or commercial noise pollution
  •  Waste being dumped into the natural environment 
  •  Improper disposal of commercial waste

The Ministry of Natural Resources and Forestry (MNRF) is also conducting an investigation into the event and results are expected in the coming weeks.

Watch for updates

We will update this page with more information in the coming weeks.

We thank you for your concern.

We look forward to working with you to take practical actions that can minimize stressors on our rivers and on our lake.