Michigan Department of Environment, Great Lakes, and Energy (EGLE) – Remediation and Redevelopment Division (RRD)


Creation of lost fish spawning rock reef habitat in Saginaw Bay.


Saginaw Bay, Michigan

Service Line

Project Highlights

  • Created 2-acres of lost rock reef spawning habitat
  • Helped to facilitate a resilient and diverse fish population
  • Served as a demonstration project for future reef restoration in the Great Lakes

Land use changes, including logging and agriculture, caused sedimentation buildup and contributed to the loss of reef habitat in the inner Saginaw Bay, Michigan. The loss of reef habitat contributed to the collapse of Saginaw Bay’s walleye fishery and negatively impacted local populations of lake whitefish, lake trout, burbot, and other species.

Working on behalf of the Michigan Department of Environment, Great Lakes, and Energy (EGLE) – Remediation and Redevelopment Division (RRD), ECT and the project team developed a 2-acre reef restoration design for the construction of the Coreyon Reef in Saginaw Bay. The team designed the reef based on lessons learned from natural and restored reefs within the Great Lakes, including the recent Detroit River reef project (Vaccaro et al. 2016), Thunder Bay reef restoration project, and the Elk Rapids (Grand Traverse Bay) reef restoration project. ECT also completed all necessary permitting and construction oversight for the project.

The construction of new fish spawning reefs will lead to greater stability of fish species native to Saginaw Bay. This project also helped to diversify spawning habitat and to facilitate a more resilient and diverse fish population. Saginaw Bay’s Walleye fishery was historically sustained by river-based spawning within one or two rivers, which left the fishery vulnerable to events that might harm spawning success within these rivers. Restoring the bay’s reefs helped to address this vulnerability by diversifying the type and location of spawning habitat. Construction of the reefs began in the summer of 2019 and was completed by fall 2019.