A beam trawl is used to capture young lake trout at East Reef in Lake Michigan - courtesy photo

Charles Bronte, Green Bay Fish and Wildlife Conservation Office, working with John Janssen of the University of Wisconsin-Milwaukee, conducted a beam-trawl survey for young wild lake trout at the East Reef located 25 miles east of Milwaukee, in Lake Michigan. 

East Reef is part of the the Mid-Lake Reef Complex, composed of four large reefs in south central Lake Michigan, and was historically one of the most important sites for lake trout reproduction. 

The Fish and Wildlife Service has been stocking yearling lake trout at these offshore sites for many years and have built up one the largest adult populations on Lake Michigan there. 

This study was funded by the Great Lakes Fishery Trust and involved a variety of techniques to document egg deposition and fry production over the last three years 

Results indicate that very few fry are produced at these locations and suggests that spawner abundance may not be as high as previously thought and/or that survival bottlenecks occur between egg deposition and the first weeks of life.