The Wellfleet Bay Wildlife Sanctuary, with support from The Nature Conservancy and the National Oceanic and Atmospheric Administration, is establishing the first oyster reef habitat restoration project in Massachusetts on the intertidal flats of Lieutenant Island. Oyster reefs are three dimensional habitats comprised of living and dead oysters, and serve multiple ecological functions; they can improve water quality by filtering and removing nutrients, suspended sediments, and chemical contaminants, create habitat for other species (especially juvenile fish and crabs), and reduce bank erosion. This habitat type is among the most endangered in the ocean; approximately 85% of oyster reef habitat has been lost around the world. In Wellfleet Bay, oyster reefs have essentially disappeared, primarily as a result of pollution, overfishing, and disease. The Sanctuary is seeking to restore these reefs because they serve as natural coastal buffers that help to protect shorelines and keep coastal marshes intact by helping to break down wave energy before it reaches the shoreline, an especially important service with the likely increases in storm surges and sea level rise expected with climate change. The aims of this project are therefore two-fold: 1) to boost wild American oyster populations and 2) to restore oyster reef habitat and the ecological services it provides to Wellfleet Bay.