Understanding Lake Trout Spatial Structure and Spawning Habitat Occupancy in Lake Erie

LELTM

March 2016 - December 2021

The Lake Erie Fish Community Goals and Objectives state that “the goal for the eastern basin is a balanced cold-water community with Lake Trout as the dominant predator.” Native Lake Trout stocks were extirpated from Lake Erie approximately 50 years ago and restoration efforts have been ongoing since the mid-1980s. The Lake Erie Committee’s “Strategic Plan for the Rehabilitation of Lake Trout” identifies three strategies for reaching the management objectives: 1) increasing stocking rates of yearlings, 2) maintaining Sea Lamprey abundances to prescribed levels, and 3) identifying potential Lake Trout spawning habitat. The first two strategies are addressed on an annual basis by the management agencies; however, the ability to address the third strategy has lagged. From 2006 to 2011, members of the Lake Erie Habitat Task Group combined efforts to conduct high resolution substrate mapping and underwater photography of potential Lake Trout spawning reefs within the eastern basin. This effort resulted in substrate classifications, bathymetry measures, and measures of connectivity to potential nursery areas. While this information indicated that potential spawning habitat existed in the eastern basin, the authors highlighted that movement data would provide the connection needed between spawning habitat and Lake Trout use. Lake Erie’s existing acoustic receiver infrastructure presents an exceptional low-cost opportunity to detect Lake Trout movements during the spawning season as well as through all seasons. Thus, this project will also inform seasonal inter-basin movements of Lake Trout. Anecdotal evidence surprisingly suggests that the western basin reefs and the Detroit River historically provided important spawning habitat for Lake Erie Lake Trout. Whether mature feral hatchery lake trout migrate to these areas during the spawning season is unknown. Lastly, an understanding of western basin versus eastern basin reef occupancy during spawning times will help inform potential stocking locations in the future. The ability to rehabilitate Lake Erie Lake Trout is hindered until more information on spawning habitat occupancy and seasonal movements are quantified. Photo Credit: Kevin Hall

• Determine whether seasonal intra-lake movement patterns occur among the eastern, central, and western basins Determine if Lake Trout at suspected spawning reefs such as Brocton Shoal and in the island and reef areas of the western basin during the sp
• Determine if Lake Trout at suspected spawning reefs such as Brocton Shoal and in the island and reef areas of the western basin during the spawning season
• Determine whether the seasonal “coldwater” habitat that Lake Trout use is broader than expected (currently thought to be limited only to the eastern basin) and to use that information to help predict future habitat availability in a changing climate.

• This project will provide managers with much needed information regarding where and when Lake Trout spawn in Lake Erie. We also anticipate developing a better understanding of how spawning and thermal ecology influence Lake Erie Lake Trout movement patterns.

• Pascal Wilkins (New York State Department of Environmental Conservation - Lake Erie Fisheries Research Unit) - pascal.wilkins@dec.ny.gov
• Andrew Muir (Great Lakes Fishery Commission)
• Chris Vandergoot (Michigan State University)
• Tom Macdougall (Ontario Ministry Of Natural Resources And Forestry)
• Chuck Murray (Pennsylvania Fish And Boat Commission)
• Ann Marie Gorman (Ohio Department Of Natural Resources)
• Mark Rogers (United States Geological Survey)
• Richard Kraus (United States Geological Survey)
• Dimitry Gorsky (United States Fish And Wildlife Service)
• Jason Robinson (New York State Department Of Environmental Conservation)
• James Markham (New York State Department Of Environmental Conservation)

• Great Lakes Fish and Wildlife Restoration Act