Milwaukee River Walleyes

MilwaukeeRiver Walleyes

By Judy Nugent

Since the complete removal of the North Avenue Dam in 1997, the MilwaukeeRiver has made significant improvements. According to a DNR report, “This project is one of the most ambitions and comprehensive river restoration projects ever undertaken by the WDNR.” Part of this restoration involves the stocking of walleye. In 1998 the Milwaukee River Walleye Restoration Plan called for 10,000 walleye to be stocked until 2004. Some worried that the program would stop this year. But a current DNR draft plan calls for a continuation of this stocking for the next five years.

The removal of the dam opened up an additional 19.7 miles of river, and gave the DNR the chance to revive a failing sport fishery area. In the 1990’s near shore anglers were facing a dramatic decline of yellow perch in Lake Michigan, and poor water quality in the LowerMilwaukeeRiver and harbor. The river and subsequent impoundment behind the dam held only 9 species. These few species could tolerate the degraded environmental conditions and offered little to no sport fishing opportunities. Since the dam’s removal the number of species has increased five-fold.

Part of this plan was the consistent stocking of extended growth walleyes of the Great Lakes strain. Extended growth walleye are larger and have a higher survival rate than the fingerlings. Yet, there is a higher cost to keeping these small fish until a fall stocking. During the summer they are fed minnows, which are more expensive, and they take up hatchery space that could be used for something else. Luckily Walleyes for Tomorrow and the Lake Shore Fishermen Sports Club came forward and made donations to cover the costs.

This additional cost is considered well worth it because of the increase in survivability. According to a DNR report on the Milwaukee River, “Since 1986, the WDNR has attempted to improve the near shore fisheries of the Lower Milwaukee River and Harbor by stocking fry and fingerling walleye, northern pike and smallmouth bass. However, fry stocking did not appear to be effective, especially with walleye.” The extended growth stocking has led to a stronger population.

Walleye stocked by the DNR have specific markers so that the DNR can keep track of growth rates for each year class. These fish are marked by either a pectoral fin clip or by a Visible Implant Elastomer (VIE). A VIE is a plastic device that is implanted just under the surface of the skin. It can be seen with the naked eye when they fish are later netted. Both markers are equally harmless to the walleye.

This spring the DNR will be electroshocking the river to study the size and survivability of each year class thanks to these markings. Any walleye found without the marking will suggest that there is natural reproduction happening in the river. At the moment the DNR has not conducted any larval studies looking for natural fry. It is believed that natural reproduction is still few and far between.