Restoring Fish Habitat

Projects in the St. Clair–Detroit River System

Michigan Sea Grant is involved in a series of projects designed to restore fish spawning habitat for lake sturgeon, walleye, lake whitefish and other native fish. The multi-agency team is currently planning one new reef project in the Detroit River.

  • Proposed – Upstream Belle Isle Reef. The proposed location is upstream of Belle Isle in the Detroit River, approximately 1,100 feet offshore from Maheras Gentry Park. The project consists of a bed of loose rock about 2-feet thick, covering 4 – 5 acres of river bottom. If planning proceeds smoothly, the reef could be built in fall of 2016.

For more information about completed reef projects, see:

Video Overview of the Reef Projects

This video focuses on the successful Middle Channel fish habitat restoration project and the science and collaboration that made it a success. (Scroll down for more videos.)

The Need for Restoration

Many fish seek out rocky areas in fast-flowing currents in order to deposit their eggs during spawning season. However, many of the natural limestone reefs and rocky areas were destroyed in the Detroit and St. Clair rivers when shipping channels were constructed. Similar spawning areas in tributary rivers were made inaccessible as a result of dams or were damaged by development and sedimentation.

Despite massive population declines, the waterways connecting Lake Huron and Lake Erie continue to support the largest remaining population of lake sturgeon in the Great Lakes. Restoration efforts in these rivers could help rebuild native fish communities throughout the Great Lakes region.

Learning to Build Reefs

Many scientists believe that the recovery of lake sturgeon is hindered by a lack of accessible, high-quality habitat, including rocky habitat needed to successfully incubate fish eggs. The remediation plans for the St. Clair and Detroit rivers call for the construction of spawning reefs to compensate for the habitat lost historically and help rebuild degraded fish populations. However, creating more spawning habitat is not a straightforward process.

The location and design of spawning reef projects are based on studies of fish populations, models of river dynamics and lessons learned from completed projects. Three experimental reefs were built between 2004 and 2013 in the St. Clair and Detroit rivers, and each has led to important lessons that are being applied to upcoming projects.

Before designing a reef project, scientists study a proposed location to determine if conditions are favorable for restoration. After a reef is constructed, the team monitors fish activity and the number and types of fish eggs and larvae to evaluate whether the reefs are promoting successful reproduction of desired fish species. This research will assist future restoration efforts and help remediate Beneficial Use Impairments in the St. Clair and Detroit rivers, as outlined by the Area of Concern program and the U.S. Canada Great Lakes Water Quality Agreement Act.

Collaborative Effort

Between 2004 and 2015, the project team created more than 12 acres of spawning habitat at six locations in U.S. and Canadian waters of the St. Clair and Detroit rivers.

Partners for U.S. projects include:

Project Funding:

The development of spawning reef projects has been supported through numerous grants, gifts and matching contributions. In addition to in-kind support from partner agencies, funding for reef restoration projects was provided by: the Great Lakes Restoration Initiative, National Oceanic and Atmospheric Administration, Sustain Our Great Lakes, U.S. Fish and Wildlife Service Coastal Program, Great Lakes Fishery Trust, Michigan Coastal Zone Management, Environment Canada, Canada-Ontario Agreement, Ontario Ministry of Natural Resources, BASF, DTE Energy, and Michigan Wildlife Conservancy.


The following videos and many of the news coverage in the right column profile the Middle Channel Reef, which was constructed in May and June of 2012.

Sturgeon Spawning on New Reefs

USGS researchers inspecting the newly constructed reefs capture delightful footage: a large number of lake sturgeon already gathering on the reefs and fresh sturgeon eggs in the crevices of the rocks.

Reef Construction Begins

Interviews with project partners, clips of the construction vessels and some footage of lake sturgeon taken near the Bluewater Bridge are featured.

Scientists Study Fish in St. Clair River Before Construction

Out of the Blue - click to view video

This Out of the Blue video illustrates how project partners are studying lake sturgeon and juvenile fish communities in the St. Clair River and the role of Michigan Sea Grant.


Featured Publications

Reef Projects Lessons Learned-cover

Environmental Assessment
Remediating Native Fish Spawning Habitat in the St. Clair – Detroit River System (June 2014)

Project Photos (Flickr sets)

News Articles

St. Clair Detroit River System Initiative

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