by: Karen Beattie, NCF Director of Science and Stewardship

The Nantucket Conservation Foundation’s Board of Trustees recently decided to retire cranberry cultivation on our Windswept Bog property (on Polpis Road) in order to pursue a watershed level wetland restoration project. These plans were covered in the Nantucket Inquirer & Mirror (our local newspaper on Nantucket,

Windswept Bog, Nantucket Conservation Foundation

Currently, there are approximately 39 acres of cranberry bog and 111 acres of non-cranberry bog wetlands on the 231-acre property, which is contiguous with several thousand acres of protected conservation land in the Middle and Eastern Moors owned by the Foundation, Nantucket Land Bank and the Massachusetts Audubon Society. Cranberries have been cultivated at Windswept since the early 1900’s. The Foundation purchased the Windswept Bog property in 1980 and it was certified as an organically cultivated bog in 2004.

The decision to abandon cranberry cultivation was based on two important factors: the many economic and climate-change related challenges facing this industry across the northeast and concerns about water quality and nutrient loading within the Polpis and Nantucket Harbor watersheds. This restoration plan does not include the Foundation’s Milestone Cranberry Bog operation, which is still being actively farmed for cranberries and will continue to host the Foundation’s Cranberry Festival annually on the Saturday of Columbus Day weekend.

Tom Larrabee, Bog Manager on the Windswept Site Visit with Alex Hackman and Helen Castles (photo: Karen Beattie)

Since the beginning of the 2019 field season, our Science and Stewardship Department has been busy investigating options for a wetland restoration and gaining a better understanding of water flow patterns through the property. In late April, Alex Hackman, the Cranberry Bog Program Manager for the Mass. Division of Ecological Restoration (MassDER) and Helen Castles, a Soil Conservationist with the USDA Natural Resources Conservation Service (USDA) attended a very productive site visit to Windswept with our staff, including Karen Beattie and Dr. Jen Karberg from the Foundation’s Science & Stewardship Department, Cranberry Bog Manager Tommy Larrabee and President/CEO Cormac Collier.

Both Alex and Helen are very excited about working with us to pursue a restoration project at this site. Through its Cranberry Bog Program, MassDER works with local, state, and federal partners, including the USDA, to assist landowners with restoring wetlands on retired cranberry bogs such as Windswept. Assistance includes technical services (such as engineering, design work and permitting), small grants, and project management and fundraising help from MassDER staff.

Windswept Board of Trustees field trip (photo: Jen Karberg).

Alex Hackman recently came back to Nantucket to give a presentation showcasing the results of a cranberry bog restoration project recently completed at Tidmarsh Farms in Plymouth, MA at the Foundation’s Annual Meeting of Members on August 7th. He did a great job informing our Board, staff, membership and the public about the process and potential results of this type of work (for more information:

Windswept Board of Trustees field trip (photo: Jen Karberg).

Soon after this presentation, members of the Foundation’s Board of Trustees visited Windswept Bog with our Science and Cranberry Bog staff for a tour of the property to gain a better understanding of the site-specific considerations that will need to be addressed in the planning phase, including how to manage the water flow in a manner that maintains Stump Pond (a unique but human-made wetland created to serve as a reservoir for the cranberry operation back in the early 1900’s). Maintaining public access, use and enjoyment of the Windswept Bog property will be a high priority for the Foundation throughout the restoration. Interpretive trails and educational signage will be incorporated into all aspects of this process.

Red maple swamps, like this wetland adjacent to Windswept, may be one wetland type included in the restoration (photo: Jen Karberg).

An additional preliminary goal for this project includes maximizing the restored wetland’s ability to filter excess nutrients to improve water quality in Polpis and Nantucket Harbors. Although organic fertilizers and other agricultural amendments have not been applied to the bog since 2017, there is likely a lingering legacy of past farming practices within the bog soils. Additionally, Windswept Bog currently has 11 sites where water inflows from adjacent homes, lawns, septic systems and roads in the surrounding watershed onto the property. Restoring naturally functioning wetland plants, soils, and water flow will enhance the ability of this property to filter extra nutrients associated with these inflows prior to water being discharged into the harbor watershed.

Preliminary planning and permitting for restoration site work will likely take multiple years and involve the use of ground-penetrating radar to assess historic pre-bog conditions, detailed elevation surveying and ground and surface water level and flow monitoring. Nonetheless, our Science & Stewardship staff have already begun collecting information on pre-restoration site conditions. This includes: capturing and tagging multiple spotted turtles on the property and tracking their movement patterns via radio telemetry; conducting preliminary water quality monitoring at multiple sites around the wetland; planning for a bird monitoring project; and undertaking plant surveys to see if there are any rare or unusual species to be considered in the restoration process and/or added to our collaborative database update for The Vascular and Non-Vascular Flora of Nantucket, Tuckernuck, and Muskeget Islands, definitive record of the plants currently on Nantucket.

We look forward to sharing many future blog posts about this project and the progress we have made over the coming years- please stay tuned!

The Nantucket Conservation Foundation is a private, non-profit land trust that depends on contributions from our members to support our science projects, conservation property acquisitions and land management efforts. If you are not already a member, please join us now!