Thompson and Rogers: Global Warming Threatens Lake Trout

Thunder Bay News:

Warming water from climate change is beginning to encroach on the habitat of Northwestern Ontario’s cold water fish. Research conducted at the Experimental Lakes Area shows the region’s temperature has warmed 0.4 C over each of the last five decades. Shorter winters are heating surface water and delaying lake trout spawning.

The runoff from increasing summer rain is causing a tea-like discolouration, affecting the water’s heat distribution and compounding the change. Added together, fish biologist Lee Hrenchuk can see consequences for aquatic ecosystems beginning to show.

“The average size of an adult fish has been decreasing over time and we’re seeing this mostly in the cold water fish species that are really dependent on having good spring periods and good fall periods where they can do a lot of eating,” Hrenchuk said.