Salt Marsh Projects
Monitoring to Guide Salt Marsh Restoration
Salem Sound Coastwatch has been involved with protecting salt marshes through long-term monitoring and data collection since 1998. In particular, we’re interested in how a salt marsh’s structure, ecosystem, and resilience are impacted by climate change and other human disturbances.
Long-term Salt Marsh Monitoring
Salem Sound Coastwatch, in partnership with scientists from Massachusetts Bays Partnership and Massachusetts Coastal Zone Management, developed the Wetlands Habitat Assessment Toolbox (W.H.A.T.), a guide to monitor salt marshes across the North Shore in order to track the habitat’s condition.
This ongoing, long-term data collection measures the biological aspects of the salt marsh, such as vegetation, invertebrates, fish, and birds, as well as physical and chemical parameters, such as erosion and salinity. Understanding how the marsh ecosystem is changing gives us a better understanding of its complexities to guide restoration efforts.
W.H.A.T. procedures use a variety of instruments and techniques to monitor salt marshes. For assessing vegetation patterns, staff and volunteers divide sections of marsh into transects, using a long measuring tape. We use a square 1m2 quadrat, shown to the right, to estimate the percent cover of various plant species across different marsh zones. Tracking marsh vegetation over many years gives us clues to better understand how and why the marsh might be changing.
Migratory birds are a great indicator of marsh health. Birds are measured using a method called “point counts,” where staff and volunteers record all species seen or heard in a fixed amount of time. To study life below the water’s surface, a trap is used to collect nekton, such as fish and shrimp, which is then counted and recorded.
In 2014, Salem Sound Coastwatch partnered with Friends of Good Harbor on the Bruce J. Anderson funded project: RISING SEA. The goal of this project is to expand on the W.H.A.T. marsh monitoring methods to include sea level rise (SLR) and its impact on marsh functions in Good Harbor Marsh, Gloucester. With this new project, additional protocols included measuring the area of salt pannes, mapping the size and recording marsh plants on a raised “island,” and measuring erosion of the Saratoga Creek. We continue to collect data here each year to document changes.
As sea level rises, erosion of the marsh bank is expected to increase. Having a baseline for erosion is important for determining when changes occur in the future. Creek width and bank height are recorded by measuring these parameters at permanent markers in the marsh.
When we observe data over a long period of time, we’re able to see distinct trends that can tell a story about the marsh. For instance, the graph displays over 20 years of data on the vegetation along the marsh creek in Good Harbor. We see Distichlis spicata, a plant that was once very abundant along the edge of the creek, completely disappear. At the same time, we observe Sueada linaris, a pioneer species that thrives in disturbed areas, take over the marsh edge.
View the results of the Good Harbor Marsh Study.
Salt Marsh Studies
In addition to ongoing, long-term monitoring of salt marshes, Salem Sound Coastwatch also partners with local universities to conduct studies. Below is a selection of salt marsh studies with which we’ve been involved:
Marsh Edge Erosion Study
This project was conducted by SSCW and researchers at Boston University to study erosion of marsh edge at Juniper Cove and SSU Old Creek Marsh over several years. In addition to the rate of erosion, the number of burrowing crab holes was also measured.
Pickman Park Phragmites Eradication Pilot Project
The project was sponsored by SSCW in conjunction with Dr. Young, biology professor at Salem State University (SSU), under a City of Salem Conservation Commission Order of Conditions. We tested three different methods to eradicate the invasive common reed, Phragmites australis, in a half-acre marsh in Pickman Park, Salem, MA. Initial post-restoration monitoring found the most successful method for removing Phragmites was to increase the salinity through saltwater intrusion.
Old Creek Salt Marsh Report
SSCW completed the Old Creek Salt Marsh Assessment and Management Plan for SSU as part of their Phase III: Restoration Assessment and Strategy. Seasonal monitoring took place from August 2009 through June 2011 with the assistance of trained SSU student interns and local citizens.
Clark Pond, Manchester Wetlands Assessment
SSCW conducted pre-restoration vegetation, nekton, and salinity monitoring in 2010 and again 2011 after the tidal restrictions were removed. The project was funded by the MA Division of Ecological Restoration.
Living Shoreline Development
Not only do we monitor and study salt marshes, but we also build them! Salem Sound Coastwatch is active in the design, planting, and monitoring of fringing marshes in the form of living shorelines. Two of our most recent living shoreline projects are in Salem, at Collins Cove and Forest River Park.
Salt marshes naturally absorb wave energy and reduce coastal flooding – 15 feet of marsh can reduce wave energy by 50% – and living shorelines do just that. They also turn previously un- or under-vegetated areas into habitat for local species to forage and find shelter.