A comprehensive evaluation and comparison of the food webs of lakes Michigan and Huron using predator diets and stable isotopes

Grant: # 1783

Grant Amount: $337,223.45

Board Decision Year: 2018

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

Department of Fisheries and Wildlife

Roth, Brian M. ([email protected]) 517-353-7854

2018 Ecosystem Health and Sustainable Fish Populations: Ecological and Biological Research to Inform Management - Ecological and biological fisheries research to inform management

Project Details

Declining alewife populations in Lake Michigan and Lake Huron are a concern for managers, because alewife supports populations of ecologically and economically important predator species, like salmon and trout. Population modeling in both lakes used data from when alewife were abundant, making these models now less accurate. This project conducted a comprehensive study of predator diets throughout Lake Michigan and Lake Huron. In Lake Huron, where the alewife population has collapsed, most predators are now eating a more diverse diet. The exception is Chinook salmon, which is still eating a diet comprised mostly of alewife. In Lake Michigan, which has a larger alewife population, predator diets are 90% alewife. Results of this study have been used in models that calculate predator-prey balances, redefine models of lake trout populations in the lakes, and assist in decision making for stocking.

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