Photo credit: Zak Allan
A newly constructed nearshore rock reef by Channel Island in Saginaw Bay is poised to increase fish habitat and improve resilience along the bay’s northeast shore.
Built through community collaboration facilitated by Michigan Sea Grant and with support from many partners and community members, the Channel Island Reef will provide critical spawning grounds for native fish, complement the successful offshore Coreyon Reef, and help ensure that Saginaw Bay’s fisheries remain healthy, resilient, and productive for years to come.
Saginaw Bay is recognized as a vital stronghold for lake whitefish, a species declining across most of the Great Lakes. Diversifying spawning locations for fish also helps make populations more resilient against pressure from invasive species, pollution, and habitat loss. The project also aligns with specific management and restoration goals, including Lake Huron Fish Community Objectives, the Lake Huron Lakewide Action and Management Plan, and recommendations in the Walleye and Yellow Perch Recreational Management Plan for Saginaw Bay.
“Saginaw Bay once had all kinds of fish habitat—coastal wetlands, connected tributaries, and rocky reefs—and each one mattered,” explained Jeff Jolley, fisheries biologist with the Michigan Department of Natural Resources. “Logging, farming, industry, and other land use changes led to the loss of many of those areas. This reef restoration is a step toward bringing that good habitat back—for the fish, and for the people of this community who are proud to see their Bay thrive once again.”
Reef Details
- What: 2.5-acre reef, approximately 570 feet long and 190 feet wide
- Where: Underwater in Saginaw Bay, 0.5 miles east of Channel Island, 2 miles from the mouth of the Saginaw River (coordinates: 43° 40.07289’ N, 83° 48.15168’ W)
- Why: Building new rock reef habitat is a key strategy for restoring healthy fish populations and maintaining resilient fisheries in Saginaw Bay. Whitefish, walleye, and other fish will use this reef for spawning (laying and fertilizing their eggs).
Photo Credit: Jill Wingfield, Great Lakes Fishery Commission
Restoring habitat through reefs
Construction of the Channel Island Reef began on September 8, 2025, and was completed on October 10. A barge deposited nearly 20,000 tons of natural limestone cobble from a local quarry on the bay floor to form a long, narrow rock mound. It rises approximately 3-4 feet above the existing lake bottom and sits at least 5.5 feet below the water’s surface, even when water levels are low. As a result of the new reef, boaters and anglers need to exercise additional caution when navigating near the nearby.
Lake Huron’s Saginaw Bay is home to rich habitats full of fish, birds, plants, and other life. Many native fish use nearshore rocky or protected areas for spawning. Historically, inner Saginaw Bay had plenty of rocky underwater mounds, or reefs, formed by glacial deposits that provided safe areas for native fish to reproduce. Crevices among the rocks protected eggs and young fish from predators and strong currents until they were large enough to swim into the open waters of Saginaw Bay and Lake Huron.
However, over time, human development placed increased demands on the land around Saginaw Bay. Timber harvest, intensive agriculture, and industrial development led to elevated sedimentation—soil and other particles carried by the water—in the bay, smothering the rocky reefs. Without active restoration, fish populations and the resilience of the bay’s fisheries remain at risk.
Why here?
Projects and locations are chosen and studied carefully to make sure they would be a wise use of funds and effort while meeting local needs. The Channel Island Reef location was identified through bottom mapping and computer models of wind, wave, and sediment movement. The nearby island partially consists of dredged material, so project partners also sampled multiple potential locations for the proposed reef to make sure the reef was located away from contaminated sediments.
Community engagement was a critical part of the project and location selection process. In 2023-24, Michigan Sea Grant helped project partners host workshops and meetings to gather input from community members on potential projects that could improve fish habitat and coastal resilience in southern Saginaw Bay. Community feedback was a critical part of identifying the Channel Island Reef as a priority project. Support and buy-in from local entities like Bay County and the Lake Huron Citizens Fishery Advisory Committee were essential to the project’s successful completion.
“It is truly outstanding when multiple agencies come together to address priority habitat projects,” said Marc Gaden, executive secretary of the Great Lakes Fishery Commission. “This reef—the result of multiple levels of government working toward a shared objective—will enhance production for many different species that support important fisheries in Saginaw Bay and Lake Huron.”
Now that construction has finished, project partners will begin monitoring fish activity at the site. This new reef will promote successful reproduction for multiple native fish species, including lake whitefish, walleye, lake trout, burbot, and more.
Shaping resilient fisheries
Channel Island Reef provides a nearshore complement to Coreyon Reef, a restored offshore reef constructed in 2019 about 11 miles from shore. The Coreyon documentary shares the story of this successful restoration effort. Researchers with Purdue University, the Michigan Department of Natural Resources, and the Michigan Department of Environment, Great Lakes, and Energy documented both lake whitefish and walleye spawning on Coreyon Reef, along with other species of fish observed on the rocky structure. Coreyon Reef is now a popular fishing site. Both Channel Island and Coreyon reefs have an exclusion zone for commercial fishing.
To learn more about construction of Channel Island Reef and other restoration work, read the Great Lakes Fishery Commission article, “Rebuilding the Reefs of Saginaw Bay: A Collaborative Effort to Restore Fish Habitat and Coastal Health.”
Channel Island Reef construction involved many partners, including the Michigan Department of Natural Resources; Michigan Department of Environment, Great Lakes, and Energy; Great Lakes Fishery Commission; National Oceanic and Atmospheric Administration; Michigan Department of Technology, Management and Budget; U.S. Fish & Wildlife Service; U.S. Army Corps of Engineers; Environmental Consulting & Technology, Inc; LimnoTech; Walsh Service Solutions, LLC; Ryba Marine; and Purdue University.
A variety of grant funds supported construction of Channel Island Reef, demonstrating broad confidence and shared investment in this project. These funding sources are the National Oceanic and Atmospheric Administration, Great Lakes Restoration Initiative, Great Lakes Fish and Wildlife Restoration Act, National Fish and Wildlife Foundation—Coastal Resilience Fund, and Dow Chemical Natural Resources Damage Assessment and Restoration settlement money, which supported feasibility studies, construction, and ongoing monitoring.
