Sturgeon Confirmed at Detroit River Spawning Reefs

A five-foot male lake sturgeon turned up at spawning reefs in the Detroit River this spring, raising scientists’ hopes that the ancient species will find the habitat suitable for spawning.

A team led by Bruce Manny of the US Geological Survey Great Lakes Science Center caught and released the 45-pound fish in mid May after implanting a transmitter to monitor its movements. After release, the fish remained in the vicinity of the reefs near Belle Isle.

“This is an excellent sign,” says Manny. “The sturgeon is in spawning-ready condition and waiting for females.” Typical pre-spawning behavior for lake sturgeon is for the males to congregate at good spawning sites until water reaches optimal temperatures and females arrive. The reefs were constructed in 2004 to provide suitable spawning habitat for lake sturgeon, which once thrived in the Detroit River.

Lake Whitefish Return
Nine other native fish species have been documented spawning at the reefs, among them walleye, yellow perch, and lake whitefish. Scientists collected the first lake whitefish eggs ever found on the river bottom near Belle Isle in 2006. The finding confirms that lake whitefish spawned at the location in the fall of 2005, Manny says, marking an event that hasn’t been documented since 1916.

According to Manny, the return of lake sturgeon and spawning lake whitefish to the Detroit River may indicate that remedial actions over the past 25 years have improved environmental conditions for fish on spawning grounds in the river. Other confirmed species at the reefs include northern hogsucker, troutperch, silver Redhorse, shorthead Redhorse, white sucker, and white bass. Invasive round gobies and white perch have also been found at the site.

The Detroit River Sturgeon Spawning Habitat Project, managed by Michigan Sea Grant, was funded by the Michigan Coastal Management Program (DEQ), the Great Lakes Fishery Trust, and DTE Energy, with support from the US Geological Survey and numerous collaborating agencies.

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