The Maine Dept. of Inland Fisheries and Wildlife owns this 10-acre island that is attached to Petit Manan Island by a bar at low tide. The island is located two miles south of Petit Manan Point in Steuben. A mixture of grasses, Rugosa rose, Angelica, and stinging nettle are the dominant vegetation here.
Great Black-backed Gull, Herring Gull, and Black Guillemot all nest on Green Island. This island is also one of four islands in Maine where American Oystercatchers nest. In 2001, over 1000 Common Eiders nested there. During the late summer months, the waters surrounding Petit Manan and Green Island support between 5,000 and 7,000 molting Common Eiders. During fall migration, the island supports a variety of shorebirds, with one of the largest concentrations of Ruddy Turnstones recorded in the state. Purple Sandpipers winter on the adjacent ledges.
The island is owned by the Maine Dept. of Inland Fisheries and Wildlife and managed as part of the Coast of Maine Wildlife Management Area. It is closed to public access during the seabird nesting season (April 15 ? August 31).