Salt Marshes


    In Context

    • Salt marshes have been playing an outsized role in stabilising the environment. But more than 90 per cent of these biologically productive ecosystems may soon succumb to sea level rise by the turn of the century.

    What are Salt marshes?

    • Salt marshes are coastal wetlands that are flooded and drained by salt water brought in by the tides.
    • They are found in intertidal zones along coastlines, usually in protected areas such as estuaries or bays.
    • They are dominated by grasses and other salt-tolerant plants such as sedges, cordgrass, rushes, and mangroves.
    • Salt marshes occur worldwide, particularly in middle to high latitudes.


    • Salt marshes also protect shorelines from erosion by buffering wave action and trapping sediments. They reduce flooding by slowing and absorbing rainwater and protect water quality by filtering runoff, and by metabolizing excess nutrients.

    Coastal squeeze

    • Marshes all over the globe experience ‘coastal squeeze,’ where their movement is obstructed by sea level rise, anthropogenic activities and geographical factors. For instance, a seawall that protects a home from inundation will prevent a wetland from naturally migrating to higher ground.
    • Sea level rise is the most important threat to salt marshes. 

    Source: DTE