FOR MORE INFORMATION CONTACT:
Lawrence Eslinger, Mercer (715) 476-7847; Steve Fajfer, Wild Rose State Fish Hatchery, (920) 622-3527; Tom Meronek, Wausau (715) 359-7582; or Jamison Wendel, Spooner, (715)635-4095
MADISON -- Work continues across the state to restore lake sturgeon to their native range, with activities this summer including stocking fish raised at the renovated Wild Rose State Fish Hatchery.
Historically, lake sturgeon were found throughout the Great Lakes and Mississippi River basin. They flourished in Wisconsin's boundary waters including the Mississippi, Wisconsin, and Menominee rivers, Lake Superior, Lake Michigan and Green Bay. Dams, pollution, habitat degradation and overharvest dramatically reduced lake sturgeon populations in some Wisconsin waters over the past 100 years, and eliminated them entirely from other stretches of water.
Because female fish don't reproduce until they are 20 to 25, and then spawn only once every three to five years, lake sturgeon populations are very vulnerable to overexploitation and other disturbances as well, according to Karl Scheidegger, co-leader of the Department of Natural Resources' sturgeon team.
The Wisconsin Lake Sturgeon Management plan has guided DNR and partners' work for the past decade or so, and that plan is now being updated. The goals continue to be to provide sturgeon harvest on waters that can handle the demand while restoring populations of the state's largest and longest-lived fish to their original range in other areas of the state, Scheidegger says.
Here are fish biologists' updates for some waters where sturgeon restoration work is ongoing, and from Steve Fajfer, supervisor of Wild Rose. More information on other waters where sturgeon populations are being restored can be found in " A Strong Base for a Broad Recovery," in the February 2009 Natural Resources Magazine.
Wild Rose State Fish Hatchery
The new and improved Wild Rose Hatchery is producing more and bigger lake sturgeon that appear healthier than before. Bigger means the managers will be able to mark fish better for determining year-class strength and growth over time. Healthier should mean better survival once they are stocked out. The staff at Wild Rose are proud of all the sturgeon work we have done here over the more than 30 years we have been raising sturgeon.
This year, in addition to raising fish that will be stocked into the Wisconsin and Menominee rivers, we are working on Upper St. Croix/Namekagon restoration and also Turtle Flambeau Flowage restoration.
We have all four strains of Sturgeon here at Wild Rose, and Brad Eggold and Steve Hogler have trailers (Milwaukee and Kewaunee rivers) that have sturgeon fingerlings in them. - Steve Fajfer, Wild Rose State Fish Hatchery supervisor.
St. Croix Basin
We've been doing some lake sturgeon restoration efforts in the St. Croix basin for more than 10 years, re-introducing lake sturgeon through stocking in areas of the Namekagon and St. Croix rivers that have been fragmented from their native range by dams. We captured lake sturgeon in the Yellow River this spring both for population assessment and as a source of eggs and milt. This fall, these fingerlings that were raised at the Wild Rose hatchery will be released in the Namekagon River and Upper St. Croix Lake as fingerlings. - Jamison Wendel, fisheries biologist, Spooner
This past spring, DNR staff from Mercer, Park Falls, and Wild Rose State Fish Hatchery collected eggs and milt from adult lake sturgeon in the North Fork Flambeau River. Collection was done below the Turtle-Flambeau Flowage dam, with much appreciated cooperation from Xcel Energy staff, who voluntarily agreed to reduce outflow through the dam. The resulting fertilized eggs were taken to the newly-renovated Wild Rose State Fish Hatchery where they will be raised to large-fingerling size (typically 4-6 inches). After reaching the appropriate size, the young lake sturgeon will board a hatchery truck and head back up to the Turtle-Flambeau Flowage area. The fish will then be stocked in the Manitowish River at a known lake sturgeon spawning area in hopes that the fish will imprint at the spawning location, and then return there to spawn after they have matured.
With the stocking of young sturgeon, along with protection of the spawning habitat, a healthy, self-sustaining lake sturgeon population (similar to the population in the North Fork Flambeau River) in the Turtle-Flambeau Flowage is the ultimate goal. - Lawrence Eslinger, fisheries biologist, Mercer
Crews recently concluded their 14th year of lake sturgeon egg collection on the Wisconsin River and were able to get enough eggs for the production of fingerlings to be used for stocking. We will be marking and stocking those fish this coming fall. Restoration of lake sturgeon on the central portions of the Wisconsin River started in 1996 when adult lake sturgeon were transplanted from Lake Wisconsin to the Stevens Point Flowage.
These fish had a habit of returning downstream though, so in 1997, the DNR started collecting eggs from lake sturgeon below the Kilbourn Dam in the City of Wisconsin Dells. Using the fertilized eggs, propagation staff at Wild Rose Fish Hatchery are able to raise fingerling lake sturgeon for stocking.
This work continues, with the latest stocking in fall 2010, when nearly 20,000 fingerling lake sturgeon were released at locations including the Wisconsin River above Wausau Dam, the Stevens Point Flowage, and Petenwell Lake.
About 14,000 of these fish were marked by removal of a scute, and another 300 were large enough to have PIT tags (passive integrated transponders) inserted. The scute removal will help biologists identify during which year a fish was stocked, and the PIT tagged fish can be individually identified if they are recaptured in a survey.
Overall, the goal is to restore naturally reproducing populations of lake sturgeon in portions of the Wisconsin River from Merrill to Wisconsin Dells. To attain this goal, more than 250,000 lake sturgeon have been stocked in the Wisconsin River.
The river is regularly surveyed to evaluate stocking success; biologists collect spine samples for age determination, look for marked fish, and compare numbers caught among years. These surveys have proven that some lake sturgeon inhabiting the river were from the very first fingerling stockings in 1997, and fish as large as 52 inches have been collected.
The results of the Wisconsin River lake sturgeon restoration program have been positive and the work would not be possible without the generous support provided by our partner Alliant Energy, which owns the Kilbourn Dam, and provides the facilities and staff needed for DNR to accomplish the egg collection task each year. - Tom Meronek, fisheries biologist, Wausau
More news from the Wisconsin Department of Natural Resources.