In January 2011, Niswander Environmental was contracted by the United States Fish and Wildlife Service to provide over $1.5 million dollars of habitat restoration services at the Detroit River International Wildlife Refuge Gateway (Gateway), a Wayne County- owned brownfield property adjacent to the Humbug Marsh Unit of the refuge. Historically, this 40-acre property was an industrial manufacturing site for 4 decades until it closed in 1990. The goal was for the Gateway site to be restored as an ecological buffer for Humbug Marsh and the future home of the refuge’s visitor center.
The 410-acre Humbug Marsh Unit is an ecologically-sensitive area since it serves as the last mile of natural shoreline along the Detroit River and supports over 300 species of birds and 100 species of fish. In addition, Humbug Marsh was recognized as Michigan’s first Ramsar Site, which designates Wetlands of International Importance.
After clearing the banks of non-native vegetation, efforts to restore the degraded shoreline were undertaken (left). Encapsulated soil lifts were installed to create a new soft shoreline. This technique utilizes a stone toe protection with soil wrapped in biodegradable coir fabric.
In addition to restoring the Detroit River shoreline, Niswander Environmental served as the general contractor for restoring 3 acres of coastal wetland. Approximately 30,000 cyd were excavated from the brownfield site to create the wetland shelf. Niswander Environmental seeded the area with a native seed mix and installed over 1,500 bare-root trees and shrubs and 21 balled/burlap trees.
Concurrently with the creation of a wetland shelf, Niswander Environmental treated non-native Phragmites within and surrounding the Gateway site, removed invasive shrubs from the Mongaugon Drain, and re-planted the steep slopes with native wildflowers. In addition, habitat enclosures were installed into the Detroit River and planted with tubers (above, right) in an effort to re-populate the shallows with native aquatic plants while preventing carp and geese from hindering establishment.
Niswander Environmental was responsible for implementing the restoration of 1,200 linear feet of degraded shoreline along the Detroit River, capping 15 acres of brownfield land with 50,000 cyd of fill, creation of 3 acres of coastal wetland, restoration of 20 acres of upland prairie habitat, seeding and planting, and invasive species control. This project has been described as transformational for the region by restoring an industrial brownfield into high quality wildlife habitat that expands the ecological buffer of a Ramsar site. This project also is consistent with ecological theory that calls for protecting habitats of exceptional biodiversity (e.g., Humbug Marsh Unit), expanding their ecological buffers (e.g., restoring fish and wildlife habitat at the adjacent Refuge Gateway), and then linking with other high quality habitats.
The Refuge Gateway will soon be home to the refuge headquarters and visitor center (above), which will provide educational and interpretive displays and programs, and will allow visitors to explore Humbug Marsh.