Lake Superior Fisheries
3:09 pm
Tue August 27, 2013

Climate Change: Good for Walleye?

A changing climate could bring one piece of good news for walleye fishermen. 

Walleye populations may benefit from warming temperatures in Lake Superior.
Credit Eric Engbretson / US Fish and Wildlife Service

A study out of the University of Wisconsin-Madison says increasing temperatures in Lake Superior will expand habitat for fish that thrive in slightly warmer water, like walleye, Chinook salmon and lean lake trout.  Researcher Jim Kitchell says that means populations of certain fish in Lake Superior could increase in coming years.  

“There will be a greater abundance of fishes that are currently limited by the cold conditions in Lake Superior.  So there will be more fish that are tolerant of warmer water, and need warmer water. ”

Cold water fish like the siscowet trout may not be so lucky.  Kitchell says warming temperatures are reducing habitat for those species. 

“The downside is that there probably are more constraints on the fish that had been the focus of most o the fishery which would be the cold water trout and salmon.  Their habitat eventually will get compressed.  And there will be increased competition and there will be a reduced growth rate for them.”

Kitchell points out increasing temperatures could also make life easier for some invasive species.  And if the lake warms too much, it won’t be hospitable even for walleye.  Lake Superior is considered the most rapidly warming lake in the world.  Scientists say average surface temperatures have gone up about six degrees since 1980.