Is Lake Simcoe’s health deteriorating due to increasing water temperatures?

With the heat continuing across central Ontario, the Lake Simcoe Region Conservation Authority (LSRCA) is working to make sure the water stays safe.

Brian Ginn, limnologist and certified lake manager at LSRCA, said there are multiple ways the conservation authority is recording data.

“About April to ice-on, we are out sampling the lake, and we do things like temperature, oxygen levels, and algae levels,” said Ginn. “We also do water chemistry, and we also sample things like aquatic plants and invasive mussels that are in the lake.”

The conservation authority has been collecting data since 2008 and says Lake Simcoe’s conditions are improving.

“Lake Simcoe is actually a lot healthier now than it was before, and phosphorus levels are very low, and we’re trying to understand why that is happening and what’s going on with that,” said Ginn. “We’ve seen temperature changes as well.”

The first heatwave of the season in June increased the water temperature by one degree.

That causes a lot of stress on the animals that live in the lake, like fish, and they’re trying to reproduce and breed at that time of year, so it’s just an extra stress on them,” said Ginn.

With water temperatures two degrees warmer on average than they were in 2008, having a direct impact on marine wildlife.

Adam Weir, a fisheries biologist for the Ontario Federation of Anglers and Hunters, said there are specific species of fish affected by the change of temperature in the water.

“Particularly cold-water fish species like lake whitefish or lake trout, and these species are particularly sensitive to changes in water temperature and rely on cooler water temperatures to carry out their life processes,” said Weir.

Which could ultimately harm recreational fishing.

“The water gets warmer, and ice season is a little shorter than what it used to be before, and that has an impact on what species can survive.

With Lake Simcoe an economic hub within the province.

“It’s estimated between $30 and $80 million annually that it brings in in terms of recreational fishing,” said Weir. “And anglers spend close to 800,000 angling hours per year fishing Lake Simcoe.”

The goal for LSRCA moving forward is to gather data on plants and the food chain in Lake Simcoe as well as educate the public and help to keep the lake safe for both people and marine life.

For more information on LSRCA, you can visit their website.