From the article:





O'Gorman suspects the turmoil in the Ontario fishery eventually will be
traced to the exotic species that have invaded the entire Great Lakes
system.

Interesting....the introduction of nonindigenous species is adversely affecting
other nonindigenous species.
Alewives, rainbows, and the Pacific salmon (Chinook and Coho) were all
introduced into the Great Lakes. Curious that the article seems to make no
mention of this.