A berm of construction debris used to fill salt marsh and steepen the shoreline along North Mill Pond many decades ago was removed in 2010 after the land was deeded to the City. Removal of the berm reestablished regular tidal flooding to over 2,400 ft2 of tidal marsh. From 2009 to 2011, the fifth grade classes at New Franklin School learned about the project and planted mussels, shrubs and marsh plants at the site. Plant survival was excellent in the low marsh (94%) and good in the high marsh (77%). By September 2011 (Year Two) plant cover increased to 42% in the low marsh and 13% in the high marsh. After the first growing season for the upper marsh (planted in May, 2011), cover reached 23%. Some fine-grained sediment was eroded from the surface of the high marsh due to low plant cover, but no linear features or erosion scours were observed. The site can be observed over time online, including construction and plant development at http://picturepost.unh.edu.
Piscataqua Region Estuaries Partnership
Burdick, David M., "Restoring Salt Marsh and Functions to Newly Acquired Shoreline in North Mill Pond, Portsmouth" (2011). PREP Reports & Publications. 17.