The lake sturgeon streamside rearing facility on the Milwaukee River, Wisconsin. - Photo by Rob Elliott

A team of biologists and researchers from the Wisconsin DNR, Michigan DNR, Little River Band of Ottawa Indians, Riveredge Nature Center, University of Wisconsin – Stevens Point, Northern Environmental Inc., and U.S. Fish and Wildlife Service's Green Bay FRO, have successfully completed the first year of a long-term project to evaluate the use of streamside rearing facilities to reintroduce lake sturgeon into several Lake Michigan tributaries. 

This cooperative effort represents a new direction of rehabilitation for this species and follows guidelines that have been developed by the Lake Michigan Lake Sturgeon Task Group. 

Critical to the approval and success of this project is the use of streamside rearing facilities, small scale portable sturgeon hatcheries designed to rear lake sturgeon under environmental conditions that are to the natural environment the fish will be stocked.  This includes raising the fish from eggs in water from the target river in hopes of facilitating their imprinting to the target rivers.

More than $500,000 in grant funding was secured from the Great Lakes Fisheries Trust and through the Great Lakes Fish and Wildlife Restoration Act to help develop, implement, and evaluate the use of five streamside rearing facilities on tributaries of Lake Michigan for the next four years. 

Rob Elliott, Green Bay FRO, is assisting with coordination and financial administration for the project and serves as chair of the Lake Michigan Lake Sturgeon Task Group that outlined the implementation procedures.  This fall marks the completion of the first rearing season for this project. 

During September and October, fingerling lake sturgeon that had been reared from eggs in the streamside facilities on the Milwaukee and Whitefish rivers are being released into those rivers, marking the start of a 25-year effort to re-establish populations in these and other Lake Michigan tributaries.

Contact: Rob Elliott, USFWS, Green Bay FRO, robert_elliott@fws.gov.

Background:  Though Lake Sturgeon have been severely depressed in Lake Michigan and the other Great Lakes for  100 years, it has only been in recent years that resource agencies have begun to look towards stocking as a means of reintroducing this species back into tributary waters of Lake Michigan where they have been extirpated or severely depleted.  But stocking sturgeon in the traditional manner, directly from hatcheries, has posed problematic due to the desire to maximize the opportunity for introduced fish to imprint to their receiving waters.  An over-riding principle and primary objective of rehabilitation plans being adopted by the Lake Michigan Management Agencies is to protect and enhance the existing populations within the basin – in other words, not to loose or put at risk the population diversity still present in the lake basin.  Lake Michigan still contains 8 known remnant populations, each of which has been found to be genetically distinct.  Existing evidence suggests that fish reared at off site hatcheries and stocked into receiving tributary waters may, upon reaching sexual maturity, stray into rivers other than the one in which they were introduced.  Because of the current low level of natural production in many of these remnant populations, the straying of individuals from stocking programs could result in outbreeding depression and reduced genetic diversity within the existing Lake Michigan populations.

Through several years of discussions and planning, of which the Service has played a significant role, the Lake Michigan Lake Sturgeon Task Group has reached a consensus that the use of streamside rearing facilities would be an acceptable means for interested resource agencies to introduce artificially reared fish into tributary waters.  The hope and expectation is that by rearing sturgeon from eggs in the receiving water with associated matching environmental conditions, the natural imprinting process might be maintained, thus increasing the likelihood that introduced fish will return and contribute to the waters in which the rehabilitation efforts are being targeted.