Aquatic Food Webs

Topic Aquatic Food Web

Understanding changes in fish populations in Saginaw Bay

Project: Impact of Exotic Species and Nutrient Decline on Fish Community Structure, and Food Web Linkages in Saginaw Bay, Lake Huron

Walleye and Yellow Perch are two key sport fish in Saginaw Bay. Over the past decade, less available nutrients, competition with invasive species and changes in the way the fisheries are managed has led to dramatic changes within the fisheries. Investigators used state-of-the-art statistical modeling techniques to quantify the impacts of these changes on fish community structure and distribution, particularly on Walleye and Yellow Perch populations. Methods included an analysis of existing fisheries data and the creation of an ecosystem view of Saginaw Bay.

R/ME-3, dates: 2003-2006
Sara Adlerstein, University of Michigan
Edward Rutherford, University of Michigan

The Impact of the Diporeia Decline on the Competitive Interactions and Distributions of Slimy and Deepwater Sculpins in Lake Michigan

R/ME-4, dates: 2003-2006
David Jude, University of Michigan

Complex Interactions Between Zebra Mussels and Phytoplankton: Variation in Grazing Effects Across the Trophic Gradient

M/PD-16, dates: 2003-2006
Orlando Sarnelle, Michigan State University

Nutrient enrichment and food web changes in Lakes Michigan and Superior

Project: Evaluation of the Trophic State of Lakes Michigan and Superior

Researchers applied a new approach for evaluating the water quality of lakes Michigan and Superior and developed a detailed database of water quality changes in the two lakes. They used oxygen isotopes to compare the rate of photosynthesis by algae to the rate respiration by aquatic organisms, providing an indicator of the level of nutrients and algae in the waters. With funding from the U.S. Environmental Protection Agency Great Lakes National Program Office, the research has been extended to Lake Erie. The work is part of the Lake Erie Trophic Status project to understand the ecosystem’s response to recent, dramatic changes in food web structure and composition. The combined data sets from Lake Erie, Lake Superior and Lake Michigan’s Grand Traverse Bay offer a unique perspective on the factors controlling the development of algal blooms and hypoxia. This information should allow us to better predict how climate change and biological invasions will affect algae growth and aquatic food webs of the Great Lakes.

R/ES-18, dates: 2000-2003
Peggy Ostrom, Nathaniel Ostrom, Michigan State University