Canada has about 3-7 million lakes which account for about 20% of the world’s freshwater.
90% of lakes are warming in the past 25 years, and ice-covered lakes are experiencing faster warming rates, including lakes in Ontario.
There seem to be two main drivers of increased water temperature: climate change and solar brightening/dimming
smallmouth bass are predicted to invade most lakes in Ontario by 2070 
walleye, a cool-water fish species, is predicted to shift its range northwards and be eliminated from the south.

  Source RCI Canada