Restoration Efforts
Recognizing their cultural and historical significance, the Wisconsin DNR began stocking the Milwaukee River with hatchery-raised sturgeon in 2003. Like salmon, sturgeons return to the river where they were born to spawn. However, the hatchery sturgeons were likely too old to imprint on the river, and are unlikely to return.
To maximize the opportunity for sturgeons to imprint on the Milwaukee River, the Wisconsin DNR and Northern Environmental designed the streamside rearing facility. This 10’ by 20’ trailer pumps water from the Milwaukee River into rearing tanks, enabling sturgeon to be raised in Milwaukee River water from day one.
The goal of the program is to produce a breeding population of lake sturgeon in the Milwaukee River. To achieve this goal, 1,000 to 1,500 sturgeons will be raised and released every year for the next 25 years. In addition to the restoration efforts on the Milwaukee River, the Wisconsin DNR is working on three other Lake Michigan tributaries.
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Return the Sturgeon
Article written by Mary Holleback in 2009
To most people Opening Day means tailgating and watching the Brewers play their first game of the season at Miller Park. For us, opening day is when we welcome a new batch of lake sturgeon to the Milwaukee River Streamside Rearing Facility (SRF). That date corresponds to the first day of sturgeon spawning which is anything but predictable. We received word on April 13, 2009 that sturgeon were seen moving up the Wolf River and porpoising near Shawano. It wouldn’t be long now! Excitement grew as we waited 12 more days for the call to head north.
Finally on April 25th the much anticipated call came. Several car loads of Riveredge members navigated their way through cloud bursts and construction up to the Shawano Dam. There we joined staff from the WDNR, U.S. Fish & Wildlife Service and hundreds of other people who had gathered along the banks of the Wolf River to witness this ancient sign of spring. A dive team from Discover Wisconsin/Mediaworks was also on the scene to film a segment to be used in a Riveredge display and on a kids program called “Into the Outdoors.”
For hundreds of years these prehistoric looking fish have annually migrated to this spawning area when the water temperature reaches about 50ºF. What a sight! The males arrived first cruising in groups of eight or more close to the surface where they are highly visible. Spawning began when a ripe (sexually ready) female entered the group. The team from the WDNR stepped into action, netting as many sturgeon as they could reach in the shallows. Each fish was then quickly processed. Their fin clip and PIT tag (passive integrated transponder) were recorded along with their length and other statistics. The milt (sperm) or eggs were collected from them and the fish were released down an improvised slip and slide back into the river. The milt and eggs were then mixed with Benton clay to keep them from sticking together.
Many males were easily caught but it took all day to catch just three ripe females. With rain and nightfall setting in it was time to call it a day. The WDNR team of Brad Eggold and Tom Burzyinski transported the gamates (fertilized eggs) to Riveredge’s SRF. They immediately filled three hatchers with the sturgeon gamates and introduced them to Milwaukee River water. The WDNR team returned to the Shawano Dam the next day to collect the additional gamates needed to fill the hatchers in the SRF. The season was off to a good start with over 33,000 gamates in the facility.
Lake sturgeon (Acipenser fluvescens) are the largest and longest-lived freshwater fish indigenous to the Great Lakes basin and its tributaries. They are listed as either threatened or endangered in 19 out of the 20 states where they are found in the U.S. Wisconsin is the only state where they are not imperiled. However, lake sturgeon were extirpated from the Milwaukee River by the 1890’s. Recently, interest has increased in restoring them to waterways where they were once found. They serve as an indicator of ecosystem health and biodiversity. Lake sturgeon are benthivores, feeding on small bottom dwelling insect larvae, crayfish, snails, clams and leeches. Therefore it’s conceivable that they may be able to help control the spread of several invasive species including zebra and quagga mussels and rusty crayfish.
Efforts to reintroduce lake sturgeon back into the Milwaukee River started in 2003 and continued for the next three years. During that time thousands of hatchery raised fish were released into the river by the WDNR. However, new research on the habits of lake sturgeon indicated that they might stray into other waterways and not find their way back to the Milwaukee River when they become adults. So in 2006, through a collaborative effort between the WDNR, U.S. Fish & Wildlife Service and others, the first Streamside Rearing Facility (SRF) in Wisconsin opened at Riveredge. SRF’s are used to rear juvenile sturgeon to enhance their chances of survival and allow them to imprint on the water they are raised on. This gives them the opportunity to adapt to the natural environment of the river that they will be released into, and hopefully return to spawn in, as adults in 10 – 20 years.
During the first three years of this restoration project, we have released 951 lake sturgeon back into the Milwaukee River. None of this would have been possible without the help of our dedicated sturgeon volunteers, and the technical support of the WDNR, and the financial support of our generous sponsors. Our goal this year, and for the next twenty years is to release 1000 per year. We are well on our way to meeting that goal. As of mid July approximately 2400 young lake sturgeon are thriving in the SRF. The surviving fish will be PIT tagged and released in a ceremony befitting these regal fish, just below the Thiensville Dam in Thiensville Village Park. If you would like to have the opportunity sponsor and release your own sturgeon, check out our website for more information. This is your chance to “right the wrongs” humans have done to the lake sturgeon when we altered their habitat and exploited them into near extinction. Please consider helping us “RETURN THE STURGEON” to their rightful home in the Milwaukee River at the next annual Sturgeon Fest event.
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