On June 21, 2017, the completion of an important island stabilization and endangered tern habitat restoration project on Bird Island was the focus of a gathering of federal, state, and local officials in the Town of Marion. Rising 10 feet above sea level, Bird Island has experienced erosion which drastically reduced critical nesting habitats for one of the largest populations of federally endangered terns in the country and threatened the historic lighthouse on the island (built in 1819). For well over a decade, the Massachusetts Division of Fisheries and Wildlife (MassWildlife) within the Department of Fish and Game (DFG) has been working with the U. S. Army Corps of Engineers (USACE) and the Town of Marion to stabilize the island, increase tern nesting habitat, and protect the lighthouse.
Bird Island hosts critically important nesting habitat for approximately 1,100 nesting pairs of federally endangered Roseate Terns. "This island is one of only three major Roseate Tern colonies in North America and one of two in Massachusetts," said MassWildlife Director Jack Buckley. "The Bird Island population represents 30% of the entire North American Roseate Tern population and 60% of the state's population. It's no surprise that this project is one of the highest priority restoration efforts on both the state and federal level." In addition, 2,500 pairs of Common Terns, a state listed endangered species, also nest on Bird Island. Over many years, the low lying graveled areas where terns prefer to nest began to flood and the amount of usable nesting space began to shrink. As the interior island areas flooded, former tern nesting areas turned into salt marsh, unsuitable for tern nesting. The more aggressive Common Terns responded by displacing Roseate Terns on the limite! d remaining nesting areas. Continued erosion also threatened the lighthouse and island itself.
To address these problems, the seawall around most of the island was redesigned and rebuilt to address projected sea level rise and reduce erosion. Gravel fill suitable for tern nesting raised the low areas, replacing the salt marsh habitat and adding additional tern nesting area. Native plants providing shade for terns were planted. A natural gravel road and pad around the lighthouse will physically support equipment needed to maintain the lighthouse.