Sturgeon haven't spawned in this river since 1843 – but may make a return. How?
Lake sturgeon were found in relative abundance in Lake Michigan and nearshore waters of Milwaukee when European immigrants settled the area.
However, the fish were extirpated over much of their range in the last 200 years due to unregulated killing, pollution and dams that blocked spawning migrations.
That included the Milwaukee River, where it's likely no sturgeon spawning has taken place since 1843, when a dam was built across the river near North Avenue.
Fortunately, the species fared much better in other parts of the Upper Midwest, including Lake Winnebago in central Wisconsin, where the population was never blocked from its spawning grounds in nearby Wolf River and, despite fears of exploitation in the early 1900s, was buoyed by protective regulations.
With the Winnebago System sturgeon population thriving, fisheries managers recognized the need to spur recovery of the species in the Milwaukee River and in select other sites around the Great Lakes.
In 2006, Rick Flood, former director of Riveredge Nature Center in Saukville, worked with federal and state agencies to initiate the Milwaukee River sturgeon rehabilitation project.
The goal is to restore a wild, self-sustaining lake sturgeon population in the urban river that runs up the northeast side of the metro area.
Its primary partners are Riveredge, the Wisconsin Department of Natural Resources and the U.S. Fish and Wildlife Service.
Riveredge serves as host for a hatchery trailer. It is run by Riveredge staff and volunteers with technical supervision by DNR fisheries personnel.
The process starts in spring when DNR fisheries employees obtain fertilized sturgeon eggs, typically from fish in the Wolf River, and deliver them to Riveredge. The fish are reared in the trailer on water pumped in from the Milwaukee River.
In a proven fisheries management strategy, the young sturgeon "imprint" on characteristics in the river water and establish it as their home.
The fish are grown for about five months and typically released in September during Sturgeon Fest, part of Harbor Fest in Milwaukee. The public can participate in the process. A donation of $15 for each sturgeon released helps support the Riveredge sturgeon-rearing program.
Since 2006 about 22,000 young sturgeon have been stocked in the Milwaukee harbor or river, according to the DNR.
Several male sturgeon reared at Riveredge have returned to the river as adults. But since it takes about 20 years for female sturgeon to achieve maturity, no sturgeon spawning activity has been observed on the Milwaukee River.
However, sturgeon experts predict it is only a matter of time.
"I fully expect you will see sturgeon spawning in the Milwaukee in the near future," said Ron Bruch, retired DNR sturgeon biologist. "And if work done in other areas is any indication, over the coming decades it's very likely they'll spread out and migrate into the Menomonee River, too."
Recent work such as the 2024 opening of the Kletzsch Falls fish passage in Glendale and the planned installation of a fish passage at Estabrook Falls further strengthen the odds of successful sturgeon spawning in the Milwaukee River, Bruch said.
The Kletzsch Falls fish passage allows fish to migrate into 25 additional miles of the state's most urban river as well as 29 miles of upstream tributaries.
The Milwaukee River sturgeon project is "just another valuable dividend" of the successful sturgeon management program in the Winnebago System, Bruch said.
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