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by: Jen Karberg, Ph.D.; Science and Stewardship, Research Program Supervisor

To celebrate the first week of spring, volunteers from island conservation groups and Madaket homeowners gathered together (socially distant!) to finally stabilize the washover dune area near the Millie’s Bridge end of Hither Creek. In about 5 hours, we planted approximately 5000 plugs of beach grass (ammophila breviligulata) and 280 seedlings of native woody plants! This planting party had been anticipated for a long time, delayed a year due to COVID-19 but the native plants are finally in place to help stabilize the washover area and encourage a native dune field to establish.

Volunteers from The Town of Nantucket Natural Resources Department, Nantucket Conservation Foundation, Nantucket Islands Land Bank, Linda Loring Natura Foundation, Nantucket Land Council, MA Aubudon and the Madaket Conservation Association gathered to tackle this enormous planting endeavor!

Volunteers planting over 5000 plugs of beach grass across the open sand near where the Silt House used to stand.

Going back in time to Halloween 2017, the island watched as the heavily vegetation dune and wetland around this end of Hither Creek was rapidly buried under sand as the ocean washed over into Hither Creek. Waves swept under the iconic silt house and Millie’s Pond filled in and became Millie’s sand beach! In the course of 12 hours, the entire ecosystem at this little corner of the island was completely altered.

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Top image depicts Millie’s Pond, surrounding vegetation and the Stilt House prior to the Oct 2017 Storm (painting by Karen Allen-Kelley). The bottom image was taken during the Storm and shows the dune erosion, deposited sand and overwash from the Atlantic Ocean (photo by Fabrizia Lu Macciavelli)

Ecologists at the Nantucket Conservation Foundation have been studying the impacts of the washover on the native vegetation and plants communities since 2017. After a few years of monitoring, it became fairly obvious that the native shrubby wetlands and bordering saltmarshes were not going to come back to the area naturally. The large amount of sand and rushing ocean washover completely changed the natural area. The dominant ecology at this end of Hither Creek was now a developing dune field system.

Looking across the developing dune field to Millie’s Bridge. The blue flags mark planted native woody shrubs. These flags will be revisited over the next few months to track plant survival.

So the next question became, how do we help this new dune field become more stable, more resistant to the forces of Mother Nature on this sand spit and can we do it as a model coastal resilience project? Loose open sand areas are extremely susceptible to movement from wind, tides and storm surges making them very low on the coastal resilience scale. As NCF ecologists tracked the changes at Hither Creek, we saw a dune building between the ocean and Millie’s Bridge. Helped along by some midnight installation of dune fencing, by people unknown, the dune elevation increased but plant colonization was moving slowly. Without the stabilizing effect of dune plants whose roots help anchor the sand in place and whose leaves trap and hold sand – the newly forming dune was very susceptible to wind and storm events.

Working with the Town of Nantucket Natural Resources Department (who own the land) and with a matching grant from the Madaket Conservation Association, NCF helped design a natural restoration effort to advance the establishment of native dune vegetation and increase the coastal resilience of this corner of the island.

Vince Murphy, Coastal Resilience Coordinator for the Town of Nantucket plants beach grass plugs. These plugs may look small now but they will green up as summer comes and quickly spread and grow across the the dune.

Overtime the beach grass plugs will spread and grow, anchoring the dune in place. The woody shrubs and some flowering plants, to be added in May, will add biodiversity and a variety of structure to the new dune field. And ecologists at NCF will continue to monitor and track plant survival and the success of this restoration which may serve as a model of native dune restoration on Nantucket. Take a walk across Millie’s Bridge this summer and stop to take in the view!

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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!