Smith, S. and Medeiros, K., 2013. Manipulation of water levels to facilitate vegetation change in a coastal lagoon undergoing partial tidal restoration (Cape Cod, Massachusetts)

East Harbor is a back-barrier coastal lagoon and salt marsh within Cape Cod National Seashore (Massachusetts), which has been undergoing partial tidal restoration since 2002. The current tidal exchange has been sufficient to elevate salinities in the open lagoon but is still too constrained by the present infrastructure to create high tides sufficient to flood the peripheral marsh areas. Consequently, an adaptive management strategy using a one-way tide gate was implemented in 2011 that let high tides into the system while blocking their escape. The increased flooding of the marsh, above and beyond what the current engineering of the system could provide by opening the restrictive culvert, raised porewater salinities in many areas and resulted in decreases in the cover of freshwater and brackish-water plant taxa—a necessary precursor for the establishment and expansion of native halophytes. This kind of adaptive-management tool can be used to enhance salt marsh restoration in systems that can only be partially restored tidally.