An Overview of the Detroit River International Wildlife Refuge by Tyler Dolin, Biological Technician
An Overview of the Detroit River International Wildlife Refuge
The Detroit River International Wildlife Refuge was formed in 2001 as a sanctuary for all native wildlife and migratory birds as well as the preservation of their natural ecosystems. The Refuge consists of 13,134 acres of total land that can be broken down into United States Fish and Wildlife Service land (2,000), State Department of Natural Resources land (8280), co-managed land (2804) and Management agreements (49) with the Refuge boundary shown in figure 1. As the only International Wildlife Refuge, a crucial partnership with Canadian Priority Natural Areas forms a large collection of land across the border, totaling 4778 acres (Figure 2). These lands fall in a priority area for migrating birds. Two migration paths cross directly through the Refuge, the Atlantic flyway and the Mississippi flyway yielding a large assortment of waterfowl, shorebirds, raptors and songbirds. Over 350 species of birds have been identified in this region with the following map giving details on where to find them;
Parts of the Detroit River International Wildlife Refuge were once the Wyandotte National Wildlife Refuge formed in 1961. The Wyandotte National Wildlife Refuge initially consisted of Grassy Island and Mama Juda Shoal in the Detroit River, but grew to include Mud Island (2000). Once the decision was made to create the Detroit River International Wildlife Refuge the borders were expanded beyond the islands with much more land incorporated. The largest addition was Humbug Marsh, Michigan’s only Ramsar site (Wetlands of International Importance). Adjacent to Humbug Marsh is the Refuge Gateway, where a visitor center, boat dock, and fishing pier are under construction with plans to be open in spring 2017.
Role with Lake Erie
The natural lands of the Refuge provide numerous environmental services beyond fish and wildlife habitat that benefits Lake Erie. The lands process excess nutrients and pollutants that are harmful to the ecosystems. The lake also contributes with unique coastal wetlands. These wetlands are controlled specifically on changes in water levels, shoreline configuration, and type of bedrock as well as climate. The coastal wetland plants adapt to stressors such as seiches and high water level fluctuations over time for a competitive advantage over other plant species. Precise shoreline configurations allow for the wetlands to form and be protected from eroding wave action. Some such shorelines are embayments, peninsulas or drowned river mouths. With Lake Erie being the southernmost lake, it allows a unique vegetation abundance compared to the other great lakes, typical of a southern wet meadow ecosystem. The bedrock in the Erie region is a limestone and dolomite mix, a comparatively soft bedrock that allows the water to manipulate it into protective environmental features such as estuaries.
Invasive species are managed on the Refuge in some instances. They remove native species from an ecosystem and decrease the quality of that habitat for resident plants and animals, in addition to growing in dense stands that can negatively impact the natural community. Some aquatic species such as European frogs-bit (Hydrocharis morsus-ranae), phragmities (Phragmites australis), flowering rush (Butomus umbellatus), water hyacinth (Eichornia crassipes), and water lettuce (Pistia stratiotes).
Terrestrial invasive species can include reed canary grass (Phalaris arundinacea), Japanese knotweed (Polygonum cuspidatum), autumn olive (Elaeagnus umbellata), tartarian honeysuckle (Lonicera tatarica), garlic mustard (Alliaria petiolate), common buckthorn (Rhamnus cathartica) and glossy buckthorn (Rhamnus frangula). These species can degrade forested or wet prairie landscapes and their respective habitats, reducing the health of the ecosystem.
These species can be controlled through prescribed fire, mowing or herbicide application. Before any treatment, field observations are collected to determine if there is a need for treatment, what the magnitude of the treatment should be and the best interest of the Refuge by the staff. For more detail on invasive species methods, see the Detroit River-Western Lake Erie cooperative weed management area 2015 annual report:
Research has been conducted by the United States Fish and Wildlife Service, the Michigan Department of Natural Resources and Eastern Michigan University. The primary target has been phragmities, (Phragmites australis), with a focus on basic field observations, effects of controlled burns, plant rhizome regrowth, historical mapping and herbicide application efficacy. There has also been work completed on ecosystem restoration and the management practices of flowering rush (Butomus umbellatus). Details can be found at the following website:
Figure 1. The Detroit River International Wildlife Refuge ranges from the Michigan-Ohio border to the Rouge River in south Detroit and with the western border as I-75 until the River Raisin, where it then becomes the North Dixie Highway/Jefferson Avenue up to the Rouge River.
Figure 2. Depiction of Detroit River International Wildlife Refuge acquisition boundary and Canadian Priority Natural Areas boundary.