Environmental stress confirmed in Island lakes fish die-off issue

MANITOULIN – The fish die-offs seen earlier this summer in Lakes Manitou and Mindemoya were the result of environmental stress, based on indicators available from the time of the incidents.

“The final results from testing at the University of Guelph found the dead fish showed no evidence of an infectious disease. Based on the available evidence, the mortality was related to environmental stress associated with the rapid warming of surface waters, following a late ice-out and cool spring,” stated Ontario Ministry of Natural Resources and Forestry (MNRF) senior media relations officer Jolanta Kowalski in an email to The Expositor.

This outcome was not a tremendous surprise to some with knowledge of fish ecology. The Expositor previously reported on the viewpoint of Fisheries and Oceans Canada (DFO) research scientist Warren Currie who stated that the situation was indicative of stress-related mortality because of lower oxygen levels and water temperature changes, based on the species involved in the die-off.

Algoma-Manitoulin MPP Mike Mantha said he was happy to hear the news but that it opens many further questions.

“It’s good to hear from the MNRF that they’re on top of the issue and that this is something they deemed as being a natural cause. But it brings us to having the greater discussion which is the actual negative impacts climate change is having. This challenges us to have those discussions,” said Mr. Mantha.

“I do understand that this is an occurrence that has happened in various locations in Canada and across the globe with other communities affected by die-offs,” he said. “It’s going to be important to engage with communities and First Nations so we can look at ways of addressing this particular incident, so we can minimize (die-off events) in the future.”