Based on historical records from the early 1900s the populations of the Eastern Oyster (Crassostrea virginica) in Wellfleet, MA have diminished drastically over the past 100 years. As a reef-forming keystone species which serves as refuge for a variety of marine organisms, helps reduce shoreline erosion, improves water quality through biofiltration, and plays a role in nutrient cycling in estuaries, this decline has had impacts on the overall diversity and abundance of marine life as well as the water quality in Wellfleet Harbor.

Up until an oyster reef restoration project was begun in 2008 by the Massachusetts Audubon Society (Mass Audubon) in partnership with the National Oceanographic and Atmospheric Administration, The Nature Conservancy, and the Town of Wellfleet, no shellfish habitat restoration projects of this kind had been undertaken in Massachusetts and Cape Cod Bays. In 2011, this three year experimental oyster restoration in Wellfleet was completed, resulting in a population between 60,000 to 250,000 oysters. 

Results indicated oyster castles to be the best substrate for oyster restoration, maintaining their structural integrity over time and showing a net increase in their oyster population each year. In addition it was noted that invertebrate abundance and diversity, as well as the incidence of shorebirds, have increased at the project site relative to control sites. American Oystercatchers, a species of management concern in Massachusetts, now regularly feed on blue mussels growing at the site as a result of this project. Preliminary data indicate that several fish species, including juvenile tautog and cunner, killifish, and even squid may be preferentially using the reef relative to adjacent control areas.

The results of this project have also shed some light on ways to facilitate the permitting process and a number of recommendations were developed including that the State provides protection for future shellfish restorations by creating no-harvest “spawning sanctuaries”. 

Details of the experimental process, data collected, and management recommendations are provided in the final report: Oyster Reef Restoration and Monitoring in Wellfleet, MA. Massachusetts Audubon Society. 2011. pdf format of Oyster reef restoration and monitoring, Wellfleet