Across the Great Lakes several efforts have been undertaken to restore historic rocks reefs providing improved spawning grounds for a variety of fish species.
Projects in the St. Clair-Detroit River System, Grand Traverse Bay and Thunder Bay have restored reef spawning habitat for lake trout, walleye, whitefish and lake sturgeon.
Michigan Sea Grant and Michigan State University Extension played a role in a number of these reef restoration projects.
New research is currently paving the way for a similar reef restoration effort in Saginaw Bay. Part of this research requires understanding the current state of historic reef sites in the inner Saginaw Bay including assessing conditions on the lake bottom.
In order to lay the groundwork for future effective reef restoration efforts, researchers need to understand how much hard or rocky substrate currently exists at potential and historic reef sites. To do this they use a special technology called side scan sonar.
Scientists from the Michigan Department of Natural Resources Alpena Fisheries Research Station used side scan sonar to develop images of lake bottom conditions at two potential reef restoration sites in Saginaw Bay as well as two sites where the remnants of historic rock reefs can be found.
Their research produced detailed maps of substrate conditions that will provide valuable information for future reef restoration efforts.