Salt marshes are critical coastal systems which offer a wide range of ecosystem services including wildlife and fisheries habitat, flood protection, and carbon sequestration (the process of capturing and storing atmospheric carbon dioxide which can contribute to climate change). These services can be disrupted by tidal restrictions, which occur when tidal exchange between upstream and downstream habitats is partially or completely blocked by infrastructure such as roads, trails, or berms.
At eight tidal restoration sites across Cape Cod, tidal restrictions were addressed between 2002 and 2010 to allow for the return of natural tidal flow. The Association to Preserve Cape Cod (APCC) evaluated the impact of tidal restoration on these sites. Together with DER, they compiled a comprehensive report to detail the results of pre- and post-restoration monitoring at these eight salt marsh restoration sites, to understand how these systems are responding to restoration.
See the full 2024 report, Monitoring and Analysis of Eight Salt Marsh Tidal Restoration Projects on Cape Cod, Massachusetts, for the full analysis and results.
You can also reference the vegetation data and analysis for the eight restoration sites here.
The Bass Creek salt marsh system in Yarmouth was restored in 2008, when DER worked with project partners to replace the severely undersized four-foot diameter culvert with a 35-foot footbridge that connects a trail on town conservation land. Addressing this tidal restriction fully restored tidal flow to 35 acres of upstream wetlands. See the site pre-restoration (top) and post-restoration (bottom).