Project Title: Efficacy of established and emerging tidal marsh restoration methods

Lead Investigator: Brian Yellen, UMass Amherst,

Onsite Contact: Sintra Reves-Sohn, UMass Amherst,

Project Description: Salt marshes are extremely beneficial to surrounding communities because they provide recreational spaces, control floods, and improve water quality. Salt marshes also effectively store carbon and are home to resident species, such as the endangered saltmarsh sparrow and commercially and culturally important fish stocks. Vegetation is key to salt marsh survival; when the marsh is flooded at high tide, salt marsh vegetation traps sand and mud, which makes it possible for the salt marsh to build upward. This is especially important for salt marsh survival when sea level is rising quickly. If the marsh can’t build elevation, it will be outrun by rising sea levels. In addition to the threat of sea level rise, the Dog’s Head Marsh at Waquoit Bay National Estuarine Research Reserve is vulnerable due to an undersized culvert that was removed in 2008. Pre-removal, the culvert prevented tides from traveling far upstream, causing the once salty ecosystem to “freshen,” which in turn causes the land to subside (become low in elevation). When the culvert was removed in 2008, saltwater flooded this upstream area, which caused the freshwater vegetation to die, and creating a muddy expanse. The aim of this project is to characterize how sediment is moving through Sage Lot Pond and into Dog’s Head Marsh at WBNERR and understand how this relates to how Dog’s Head Marsh’s vegetation has adapted post-culvert removal. With this information, we can better predict how Dog’s Head Marsh will continue to adapt to rising sea level and we can make recommendations to how to best preserve the salt marsh.