Lake Michigan Lake Sturgeon Rehabilitation

The Wisconsin Department of Natural Resources has developed a Lake Sturgeon Management Plan for the entire state. As part of this plan, certain Lake Michigan tributaries have been identified in the priority list of Wisconsin Lake Sturgeon Rehabilitation waters. 

Historical Locations

The lake sturgeon occurs in the Mississippi, Lake Michigan, and Lake Superior drainage basins. In the Lake Michigan basin it occurs in Green Bay, Lake Michigan, the Menominee River upstream to the White Rapids Dam, the Fox River upstream to Lake Puckaway, and the Wolf River upstream to Shawano. This system includes Lakes Winnebago, Butte des Morts, and Winneconne, and the Embarrass River. The lake sturgeon is listed as a rare species in the United States. Over most of its range in the United States, it appears to be threatened. In Wisconsin, it is common in the Menominee River, the lower Wolf River, Lakes Poygan and Winnebago, Lake Wisconsin, the St. Croix River to Gordon Dam, Namekagon River below Trego Dam, and the Chippewa and Flambeau rivers. It is uncommon to rare in the lower Wisconsin River, Mississippi River, the Madison lakes, and Lakes Michigan and Superior. The Wisconsin Department of Natural Resources has given the species “watch” status.

Because Wisconsin has given the Lake Sturgeon a "watch" status, the Department is committed to rehabilitation of Lake Sturgeon in extirpated areas. In 2002, the Department requested 2,000 fingerling Lake Sturgeon be produced for the Milwaukee River. We stocked these sturgeon in the fall of 2003 and continued this type of stocking until 2006.  Starting in 2006, streamside rearing facilities have been used to produce Lake Sturgeon for stocking into the Milwaukee River.  In order to gain knowledge on sturgeon habitat use, seasonal migration patterns and effects of barriers to that migration, detailed life history information must be gathered. We used radio telemetry, sonic telemetry and PIT tags to help us fill in the data gaps that exist for Lake Sturgeon in this system.

The main goals of the rehabilitation of Lake Sturgeon in the Milwaukee River are to enhance the lake sturgeon population and life history information needs, identify critical habitat and barriers to migration. These goals fit with the vision of a Healthy Great Lakes Ecosystem described in the Strategic Vision of the Great Lakes Fishery Commission for the Decade of the 1990s2 and with Wisconsin's Lake Sturgeon Management Plan1. In addition, while not Atlantic Sturgeon, this project will follow closely the prioritized anadromous fish research areas for Atlantic Sturgeon namely obtain baseline data on habitat condition and quantity in important sturgeon rivers and establish tagging programs to delineate migratory patterns and stock composition. .

Objectives

• Annually stock 1,000 fingerling Lake Sturgeon using streamside rearing facilities

• Develop sturgeon population assessments on the Milwaukee River 
• Conduct life history research/assessments.

• Identify critical habitats and habitat requirements for various life stages 
• Identify barriers and other factors within systems negatively affecting sturgeon populations

Approach

To take a tour of the inside of the trailer, click on the link below.

Milwaukee Sturgeon trailer

Marking

Fisheries Management has employed several techniques to track lake sturgeon once they are stocked. These techniques include fin clipping, PIT tag insertion, radio and sonic telemetry.

Fin Clipping

PIT tag

PIT tags are a low frequency, passive, radio frequency identification tag (PIT tag) that are used to track fish and wildlife. The PIT tags are encapsulated in glass and provide 100% unique identification.  This allows us to tag individual lake sturgeon and if they are captured in the future will allow us to indentify that particular sturgeon. As we stock more lake sturgeon from these facilities, this will give us a tremendous amount of information on movement patterns, survival and mortality rates.

Radio and Sonic Telemetry

To assess the short-term movement patterns of newly stocked Lake Sturgeon, we have surgically implanted both radio and sonic telemetry tags into small sturgeon. Both of these devices allow us to track the movement patterns for about 50 days post-stock or until their internal batteries are depleted. With radio telemetry tagging, the individual transmitters are cheap and the equipment used to track the sturgeon consist of a radio antenna and receiver. While these are relatively cheap the large costs come from deploying personnel into the field to track these fish on a daily basis covering the entire 20 miles of the Milwaukee River. In 2006, we implanted 10 lake sturgeon with these type of tags and tracked their movement for about 8 weeks.

With sonic tags, the individual tags and receivers are more costly but once the units are deployed in the field tracking of the fish are easy. The receivers listen for pings generated by the tags and record them for future download into a computer for analysis. In 2007 and 2008, we implanted a total of 13 tags and recorded their movement patterns.