salt marsh

Vegetation growing in a salt marsh. Salt marshes are among the world's most productive ecosystems. The daily ebb and flow of the tide carries nutrients into the salt marsh and removes waste material. For plants to survive in the salt marsh they must be able to survive being covered by seawater at high tide, being exposed at low tide, and the rapidly shifting mud flats. These specialized plants (helophytes) have deep roots to anchor the plants in mud, and can survive in seawater.

Wetland with halophytic vegetation (tolerant to seawater). Salt marshes develop around estuaries and on the sheltered side of sand and shingle spits. They are formed by the deposition of mud around salt-tolerant vegetation. This vegetation must tolerate being covered by seawater as well as being exposed to the air. It also traps mud as the tide comes in and out. This helps build up the salt marsh. Salt marshes usually have a network of creeks and drainage channels by which tidal waters enter and leave the marsh.