A Quantitative, Lake-Wide Assessment of Lake Trout in Lake Michigan

Grant: # 1721

Grant Amount: $236,687.30

Board Decision Year: 2017

Michigan State University - Department of Fisheries and Wildlife (East Lansing)

Department of Fisheries and Wildlife

Clark Jr., Richard ([email protected]) 517-432-5099

2017 Ecosystem Health and Sustainable Fish Populations: Ecological and Biological Research to Inform Management - Ecological and biological fisheries research to inform management

Project Details

Researchers organized datasets and developed models that can be used to estimate vital statistics of the lake trout populations in Lake Michigan. Their stock assessment models covered areas of Lake Michigan where no such models existed before. These efforts advanced the understanding of lake trout populations in these areas, as well as, for the entire lake, because it expanded the use of modern stock assessment to cover the entire lake. Using output from the new SCAA models and the existing models in the 1836 Treaty ceded waters, they were able to make Lake-Michigan wide estimates of lake trout abundance, population biomass, and population prey consumption. Last, researchers developed a forecasting model to predict future lake trout populations, given assumptions about future management activities and ecological conditions. This model will help managers understand the relative effects of changing the conditions on the trajectory of future lake trout populations. As part of the forecasting model, they developed a spawner-recruitment curve that quantitatively described relative effects of lake trout spawner biomass and alewife biomass on lake trout natural reproduction in two regions of Lake Michigan. They suggest that this spawner-recruit curve could help managers to develop policies to enhance natural reproduction of lake trout in these and other areas of the Great Lakes.

The final report for this project can be accessed at this link.