A Canadian/US initiative hopes to restore Lake Huron’s cisco population.
Formerly known as the lake herring, cisco was, at one time, an important native prey species for lake trout and walleye in Lake Huron, but their numbers collapsed during the 1940s due to competition from invasive species such as alewife and rainbow smelt, as well as overfishing and water quality issues.
The collapse hit Michigan’s Saginaw Bay hardest, but reduced populations still exist in Lake Huron’s North Channel and parts of Georgian Bay.
Opportunity for reintroduction
The opportunity for the reintroduction came with the collapse of alewife in 2003 and reduced rainbow smelt numbers. At that time, fisheries managers decided to replace those non-native species. This effort is unique since it is only the second time a baitfish reintroduction like this has occurred.
Ontario’s Ministry of Natural Resources and Forestry is one of the many partners in the initiative, including the Michigan Department of Natural Resources, the US Geological Survey, the Fish and Wildlife Conservation Office and aboriginal stakeholders.
Diversifying food sources
Ken LaCroix, manager of the Upper Great Lakes Management Unit of MNRF, said benefits of the reintroduction should be seen across Lake Huron. Recent tracking of walleye and lake trout show these species from Saginaw Bay travel into Canadian waters.
“Diversifying food sources for fish predators like lake trout and walleye should help improve growth rates and potential as well as reproductive output for both species,” he said, adding it would also help alleviate predator pressure on perch and assist that species as well.