• Start-up
  • Planning
  • Action
  • Evaluation

This highly collaborative project was led by the Wisconsin Department of Natural Resources and Audubon Great Lakes with Focus Area 4 funding through the Great Lakes Restoration Initiative

The project focuses on increasing marsh bird habitat quality by managing invasive plant species, maintaining and enriching native plants, and increasing hemi-marsh conditions at Allouez Bay (Wisconsin). Climate challenges for this project include the potential for increasing high-energy storm events and rapid, high magnitude water level changes.

Project Area

Map of vegetation in Allouez Bay
Allouez Bay is located within the St. Louis River Estuary (SLRE) in Douglas County, Wisconsin. Much of Allouez Bay is within the top 20% of Great Lakes Coastal Wetlands for breeding marsh birds. These birds utilize emergent marsh vegetation located currently in the southern and eastern portions of the bay.

Hemi-marsh is a condition or state of marsh that offers well intermixed areas of open water and emergent vegetation, and provides the optimal conditions for breeding marsh birds. Hemi-marsh condition is dynamic in nature, driven by ecosystem engineers (largely muskrats and beavers) and fluctuations in water levels; in general hemi-marsh conditions exist in about 3-6ft of water. Across the Great Lakes, the extreme and rapid fluctuations in water levels combined with the impacts of non-native plant species have limited the availability of hemi-marsh. This project seeks to increase marsh bird habitat quality in Allouez Bay by increasing hemi-marsh conditions and overall structural diversity.

Management Goals

Closeup of American bittern in vegetation

Major goals for this project include:

Increase and sustain the extent of hemi-marsh habitat by increasing interspersion across at least 150 acres in Allouez Bay

Create conditions that allow for a dynamic and resilient marsh that provides sustainable breeding habitat for American Bittern, Least Bittern, Marsh Wren, Pied-billed Grebe, Sora, Swamp Sparrow and Virginia Rail.

Create conditions that allow for a dynamic and resilient marsh that provides shorebird and fish spawning habitat, and the potential for occasional or regular breeding by Black Tern and Yellow-headed Blackbird. 

Challenges and Opportunities

Overall, climate-influenced stressors limit the extent of emergent marsh habitat in Allouez Bay and affect the quality and extent of existing floating mat vegetation. This will challenge the ability to achieve project goals and objectives. However, there may be some climate-related opportunities as well:


Increasing storm surge activity can disturb vegetation and make it more difficult for vegetation to establish. Both of these challenges may be exacerbated when lake levels are high.
Rapid fluctuations between high and low lake levels are expected, along with possible greater magnitudes of change. Hemi marsh may not do very well with rapid year-to-year changes.
Invasive species could become more common with climate changes and climate-related disturbances.
Increased extreme precipitation events may increase runoff of sediment and nutrients, decreasing water quality and favoring invasive species.


Periods of low water levels may provide increased access and opportunity to seed and plant desired vegetation, and may favor establishment of species like wild rice.
Allouez Bay is already somewhat protected from storm surge activity, and there may be more opportunities to enhance this protection.
Less ice shearing of vegetation is possible.

Adaptation Actions

The project team used the Adaptation Workbook to and the draft menu of Great Lakes Coastal Adaptation Strategies and Approaches to develop several adaptation actions for this project. One of the main outcomes of this discussion was altering the sequence of each restoration phase in the Bay, in order to reduce the vulnerability of restored marsh to climate change impacts. The three restoration phases planned for this project include:

  • Light touch invasive control, enhancement of native vegetation, more detailed bathymetry mapping
  • Reducing exposure by constructing wave attenuation structures and gradualizing slope of the bay in some areas
  • Heavier cattail management in areas protected by phase 2 actions to create hemi-marsh conditions

Some of the specific Adaptation Approaches discussed by the project team include:

A table with select adaptation actions for Allouez Bay


Project participants identified several monitoring items that could help inform future management, including:
Post-restoration bird species
Native vegetation, including wild rice, high floristic quality areas
Invasive vegetation
Vegetation complex (degree of interspersion)
Habitat indicators, such as Black Terns and muskrats

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Wildlife habitat