Machias Bay extends from the mouth of the Machias River at Machiasport to the Libby islands approximately three miles offshore. The eastern side of the bay is split by Sprague Neck, with the northeaster portion known as Holmes Bay. At low tide, significant tidal flats can be found. Numerous small islands and barren ledges provide habitat for seabirds and wintering waterfowl.
Machias Bay is an especially important area for feeding and roosting shorebirds especially peeps. This area also supports large numbers of wintering Black Ducks.
Portions of Machias Bay are designated as Areas of Shorebird Management Concern that qualify as Significant Wildlife Habitat under Maine?s Natural Resources Protection Act. This requires a permit for placement of permanent structures such as docks within the intertidal zone. Increasing coastal development is always a threat to sensitive species such as shorebirds. Though Washington County, in general, is not characterized by the rate of development that has been seen in southern and midcoast Maine, waterfront property is always at a premium. Threats from a coastal oil spill could have serious consequences for marine life in Machias Bay.
The bulk of the lands in this area are privately owned. The best viewing, therefore, is by water. Public boat launches are available in the village of Machiasport and in Bucks Harbor.