Estuarine, intertidal, organic, partly enclosed, eulittoral

This category includes both protected beaches where silt settles and is typically anoxic, and a variety of marsh types, varying with intertidal elevation and salinity. Characteristic vegetation varies with these two key factors. Marsh vegetation can form just at the high water mark on beaches, along the edges of tidal sloughs, or in transitional areas between beaches and uplands and between estuarine and freshwater andenvironments. Substrata are usually organic, either peat for areas transitional between wetland and upland, or muck for areas transitional between freshwater and estuarine. Other substrata in these areas are sand (along stream channels) and clay.