Botanically the name coastal meadows is given to meadows that are situated on the seashore and are to a lesser or greater extent under the influence of saline seawater (in zoological terms, the concept of coastal meadows is often also extended to meadows in the coastal zone that are not under the influence of seawater). The coastal area can be divided into subsaline, saline and suprasaline zone depending on the altitude and the resulting intensity of the influence of seawater. The subsaline zone is a coastal area that is flooded permanently or for long periods, and where the lower parts of plants are permanently submerged; the saline zone is in the area of influence of seawater during wave action or high tide; marine influence usually does not reach the suprasaline zone. Coastal vegetation is also influenced by the mechanical effect of wind, waves and ice. As a result, a more or less clear zonation is characteristic of the vegetation of the seashore.

More info:
Detailed overview in English about Estonian coastal meadows and instructions for the management and restoration