Riveredge volunteers are key to sturgeon restoration
SAUKVILLE – It’s about 18 feet long and 7 feet wide and parked on a concrete slab at Riveredge Nature Center within a short hike of the Milwaukee River.
As trailers go, it looks pretty conventional.
But step inside and you immediately realize this is no ordinary pull-behind.
To the right a sign says, “Welcome Year 17!” and to the left is a series of bathtub-sized tanks, each holding dozens of dark, agile fish.
And not just any fish, but one of our most ancient and revered: lake sturgeon.
This wheeled structure sits stationary but is designed to deliver a brighter future for sturgeon in the Milwaukee River.
And its drivers are Mary Holleback, Riveredge assistant science director and sturgeon project coordinator, and about 30 volunteers.
The Riveredge trailer functions as a sturgeon rearing facility. Eggs are brought to the site, typically in early May, and hatched. The fry are then raised to fingerling size and in late September stocked into the Milwaukee harbor.
Holleback likens the months of care required for the sturgeon as having an infant in your house.
“Feedings at breakfast, lunch, dinner and once in the middle of the night,” Holleback said. “It’s very gratifying to see them grow.”
It’s all part of “Return the Sturgeon,” a project to restore a wild, self-sustaining lake sturgeon population in the Milwaukee River.
Though there are several other similar sturgeon rearing trailers in the Great Lakes, the Riveredge facility is the only one run by volunteers (Holleback supervises).
Crews of four to five show up each day of the week from May through September to feed the fish, clean tanks, check pumps and monitor critical values in the water.
“It’s a privilege to work with these fish,” said Sue Herron of Cedarburg, who along with Fred Rusch of Cedarburg got a 10-year volunteer pin last week. The volunteers are part of the Thursday crew.
More than 100 years old and a living relic from the dinosaur age, lake sturgeon are the largest (sometimes exceeding 200 pounds) and one of the oldest species of fish in the Great Lakes.
But they were extirpated in much of their range over the last 200 years due to unregulated killing, pollution and dams that blocked spawning migrations.
The Milwaukee River has likely not had natural reproduction of sturgeon since the 1800s.
But the Riveredge sturgeon trailer, powered by its volunteer force and with the Department of Natural Resources and U.S. Fish and Wildlife Service as partners, is on a mission to change that.
The Riveredge sturgeon hatchery was established in 2006 when Rick Flood, former Riveredge director, worked with the federal and state agencies to get the facility in place.
Funding included about $150,000 from the USFWS, including a grant through the Great Lakes Restoration Initiative.
The location on the bank of the Milwaukee River is strategic and critical. In a miracle of nature, the fish imprint on the river water pumped into the sturgeon-rearing tanks in the trailer. And then when they are adults, they return to their home water.
In 2021 Holleback and her Riveredge sturgeon volunteers got a joyous report when one of their 2007 year class of fish returned to the Milwaukee River. The fish’s passive integrated transponder (or PIT tag) provided the proof.
Now the next milestone is in their sights: sturgeon spawning on the Milwaukee.
“We are just so excited looking forward to the day when sturgeon naturally reproduce again on the Milwaukee River,” Holleback said. “Until then, we’ll keep doing everything we can to build the population.”
The Department of Natural Resources is a key partner in the sturgeon restoration project. Not only do DNR crews collect sturgeon eggs in spring on the Wolf River and deliver them to Riveredge, but they mark and tag the fish prior to release.
Thursday DNR staff, including Brad Eggold, Cheryl Masterson and Aaron Schiller, processed the 2023 cohort of Riveredge sturgeon.
Over about three hours, they handled 590 young sturgeon. All were weighed and measured and received a right ventral fin clip; 455 of the largest fish also were implanted with a PIT tag.
Some of the sturgeon were as small as 3 inches long and 0.07 ounces, others more robust at about 7 inches and 1 ounce.
The average length of sturgeon reared at Riveredge this year was 5.4 inches long, down from 6.2 in 2021 and 5.8 in 2022.
The PIT tag can be detected by a sensor array placed in the Milwaukee River. The system works around the clock and sends alerts to the DNR when a tagged fish passes through the area.
The public can help celebrate sturgeon and even sponsor and release a young sturgeon Sunday at Sturgeon Fest, part of Harbor Fest in Milwaukee.
The events will be held in Milwaukee’s Harbor District on the east end of the UWM School of Freshwater Sciences, 600 E. Greenfield Ave., Milwaukee. The events run from 11 a.m. to 3 p.m. with sturgeon releases planned for noon to 2 p.m.
People who want to release a sturgeon must preregister.
Harbor Fest will include musical and dancing performances, art displays, food vendors and rock wall climbing as well as tours of UWM’s School of Freshwater Sciences and tugboat rides through the Port of Milwaukee.
In spring 2021 when adult sturgeon started showing up with increasing frequency in the Milwaukee River, I wrote a column about the need for education about and protection for the fish.
Sturgeon are especially vulnerable to poaching and harassment as they gather to spawn in shallow water in spring. The recovering wild sturgeon population in the Milwaukee River deserves all the protection it can get.
I referenced a program called Sturgeon Guard run for about 30 years on the Wolf and Fox rivers in central Wisconsin. It was a collaboration between volunteers and the DNR (and now run entirely by volunteers) and puts teams of guards out on the rivers to share sturgeon information with the public and watch for any illegal activity.
Based on responses from readers over the last couple years, I know many people care deeply about the success of the Milwaukee River sturgeon restoration project.
Well a Milwaukee-based initiative to protect sturgeon has advanced over the last several months. Last week a founding group of members, including Cheryl Nenn and Mark Denning, picked a name.
The group is called Sturgeon Protectors and its mission is to “work together to engage our diverse community to protect the sturgeon.”
The group is seeking volunteers to help with its work. To get in touch, visit sturgeonprotectors.org. The group is also planning to have a presence Sunday at Sturgeon Fest.
Sturgeon Protectors is planning monthly meetings; the next is scheduled for Oct. 12 at the UWM School of Freshwater Sciences in Milwaukee.