Natural Selection and Lake Superior Fisheries

During the past 10 years, I have spent between 20 to50 days per season on Lake Superior aboard one of the University research vessels, a commercial vessel, or sport trolling. Like most other sportsmen, I am thrilled to hook a 8-10 pound salmon and satisfied to return home with a catch of six 1-1/2 to 6 pound lake trout. However, the research I have done on the lake makes me realize that things are nothing like they used to be and that the introduction of exotic fish species, which the salmon I love to catch represent, is the primary cause for the lake's present limited capacity to pro­ duce good sport or commercial catches