Lake Whitefish Return to the Detroit River after Long Absence

Ann Arbor, MI — Lake whitefish, the most sought after commercial species in the Great Lakes, are spawning again in the Detroit River. Spawning-ready adults, healthy eggs, and larvae were collected in the river in 2005 and 2006.

Prior to 1925, thousands of lake whitefish migrated from Lake Erie into the Detroit River in the fall to spawn among the large expanses of limestone and rocky areas in the river. They provided profitable commercial fisheries and also provided an accessible source of eggs for hatcheries that stocked young fish into other waters. The spawning runs ended during the 1920s due to spawning habitat degradation, reduced water quality, and sea lamprey predation. Perhaps the greatest harm to lake whitefish in the Detroit River came from removal of the rocky spawning areas during construction of shipping channels to help large ships navigate the river.

After 1972, water quality in the river improved due to municipal and industrial wastewater treatment. The lake whitefish population in Lake Erie increased due to restrictive management strategies and control of sea lamprey. Harvest of lake whitefish in Lake Erie has increased steadily since the mid-1980s. By 2001, conditions improved for fish in the Detroit River; lake sturgeon spawned there and walleye, yellow perch, and smallmouth bass populations increased. By 2005, scientists suspected that conditions in the river had improved enough for reproduction by lake whitefish, a species requiring good habitat and water quality conditions.

In fall 2005, during the lake whitefish spawning period, scientists from the U.S. Geological Survey Great Lakes Science Center in Ann Arbor, MI and the U.S. Fish and Wildlife Service Fishery Resources Office in Alpena, MI sampled for lake whitefish adults and eggs in the river using gillnets and egg pumps.

"We collected a spawning-ready male lake whitefish and several dozen healthy eggs, proof that lake whitefish were spawning in the river," said Ed Roseman, Fishery Biologist at the USGS Great Lakes Science Center. "In spring of 2006, several hundred lake whitefish larvae were also collected from the river, proof that the lake whitefish reproduced successfully."

Future research efforts will attempt to quantify the extent of lake whitefish spawning in the river and determine the importance of this spawning population as a source of young fish for the Lake Erie lake whitefish population.

Original Publication Information

Results of this study "Evidence of Lake Whitefish Spawning in the Detroit River: Implications for Habitat and Population Recovery," are reported by Edward F. Roseman, Gregory W. Kennedy, James Boase, Bruce A. Manny, Thomas N. Todd and Wendylee Stott in the latest issue (Volume 33, No. 2, pp. 397-406) of the Journal of Great Lakes Research, published by the International Association for Great Lakes Research, 2007.

Contacts

For more information about the study, contact Edward Roseman, USGS Great Lakes Science Center, 1451 Green Road, Ann Arbor, MI 48105; eroseman@usgs.gov, (734) 214-7237.

For information about the Journal of Great Lakes Research, contact Marlene Evans, Editor, National Water Research Institute, 11 Innovation Boulevard, Saskatoon, SK, S7N 3H5, Canada; editor@iaglr.org; (608) 692-1076.

Links

Since 1967, IAGLR has served as the focal point for compiling and disseminating multidisciplinary knowledge on North America's Laurentian Great Lakes and other large lakes of the world and their watersheds. In part, IAGLR communicates this knowledge through publication of the Journal of Great Lakes Research, available to members in print and electronic form. A searchable archive of the journal is available online and includes the abstracts of articles from the journal's inception in 1975 through the most recent issue. In addition, complete articles are available to members who have signed up for an electronic subscription.