Grassy Island

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Grassy Island is a 72 acre island in the Detroit River, situated between the City of Wyandotte and Fighting Island, and north of Grosse Ile Township. 

  • History

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    In 1961, Congress declared Grassy Island and the surrounding shoals a National Wildlife Refuge (NWR), named Wyandotte NWR. The U.S. Army Corps of Engineers (COE) used this island as a disposal facility to dispose of contaminated sediments dredged primarily from the Rouge River. From the years 1961 and 1982, over three million cubic yards of dredged sediments were deposited into Grassy Island. Grassy Island is now part of the Detroit River International Wildlife Refuge.  Find out more about the history of Grassy Island HERE

  • Site Description

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    Grassy Island and its surrounding shoals provide habitat for fish and wildlife resources in the lower Detroit River. The island is located along the migration corridor for many bird species including osprey, bald eagle, ducks, geese, swans, and peregrine falcons. The wild celery beds along the shoals of Grassy Island provide wintering habitat for numerous waterfowl including canvasback and redhead ducks. In addition, the surrounding waters provide a diversity of habitats from shallow slow water shoals to deep flowing water with rocky shorelines thereby supporting a diverse warmwater fish community. Fish species found at the refuge include rock bass, yellow perch, walleye. Historically, lake sturgeon have spawned 1/4 mile north of Grassy Island. Lake sturgeon, are listed as either threatened or endangered by 19 of 20 states within their original range in the United States. 


    As the Grassy Island disposal facility was constructed without an impermeable liner or cap, the Service is concerned that wildlife in direct contact with island are being exposed to contaminants and that contaminants may be seeping into the Detroit River. The Service and the U.S. Geological Survey have conducted surveys to quantify contaminants present in the plants, biota, soils, and sediments of Grassy Island. Soils and sediments within the disposal facility have elevated concentrations of a variety of organic and inorganic compounds. The Service collected waterfowl from Grassy Island, which were found to have polychlorinated biphenyl (PCB) concentrations in excess of the U.S. Food and Drug Administration's Tolerance Level for poultry. Lead was also detected at levels of concern. 


    The Service is currently moving forward on plans to more fully characterize the risks from the identified contaminants and evaluate the feasibility of several approaches to both remediate contaminant risks and enhance long-term benefits of the area for fish and wildlife. The process the Service is using is the CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act) framework for conducting remedial activities. 


    For more information concerning Grassy Island, contact:

      Dr. John Hartig, Refuge Manager

     Detroit River International Wildlife Refuge

    Large Lakes Research Station

    9311 Groh Road

    Grosse Ile, Michigan 48138

    Office: 734-692-7608  Facsimile: 734-692-7603

  • Species Lists

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    Discover the plant and animal species observed on and surrounding Grassy Island.










  • Reports & Memos

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    A number of reports and memorandums relating to Grassy Island are available for download HERE.

  • Frequently Asked Questions

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    Click HERE to view a list of questions typically asked along with the answers. This list was prepared to help people better understand the site by providing concise information regarding the site's background and current status. You will need Adobe Acrobat Reader installed on your computer to view the FAQs.

  • Public Records

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    Grassy Island Update - February 2016

    Creating a Vision for Grassy Island: Public Comment on the Future Uses of Grassy Island - 1/31/06, Trenton, Michigan

    Discussion Record - Grassy Island Public Forum 12/1/2005, Wyandotte, Michigan 

    Discussion Record - Grassy Island Public Forum 3/9/2006, Wyandotte, Michigan

    Grassy Island Public Forum Presentation - 10/12/2006 (1840 kb)  

    Grassy Island Presentation - "Moving Towards Remediation and Restoration at Grassy Island"