Facilitate tidal exchange to restore degraded freshwater marshes
Overall effectiveness category No evidence found (no assessment)
Number of studies: 0
Background information and definitions
This action involves facilitating tidal exchange to degraded marshes (i.e. still recognisable as, or retaining substantial characteristics of, the target habitat). The action could be a single permanent one (e.g. breaching sea walls or embankments, installing or widening culverts, excavating tidal creeks) or a reversible one (e.g. opening sluice gates once per day). Facilitating tidal exchange can affect multiple properties of a site: it can raise moisture levels, raise or reduce salinity, increase physical disturbance, and increase supplies of sediment and wetland plant propagules.
Tidal wetlands may be brackish/saline (e.g. mangroves, coastal marshes) or freshwater (e.g. at the upstream end of estuaries, as in the Mississippi, Yangtze, and Elbe rivers; Baldwin et al. 2009).
Studies of accidental restoration of tidal exchange, such as when coastal defences are breached by a storm, have not been summarized as evidence.
Related actions: Facilitate tidal exchange to restore/create marshes from other land uses; Add salt to control problematic plants; Reprofile/relandscape or Remove surface soil/sediment, both of which can alter patterns of tidal exchange.
Baldwin A.H., Barendregt A. & Whigham D. (2009) Tidal Freshwater Wetlands. Backhuys Publishers, Leiden.