Salt marshes are a type of wetland ecosystem that is characterized by the presence of saltwater and salt-tolerant vegetation. Synonyms for salt marshes include tidal marshes, estuarine marshes, saline marshes, and brackish marshes. Tidal marshes are so called because they are influenced by the regular ebb and flow of the tide. Estuarine marshes are found at the boundary between freshwater and saltwater environments. Saline marshes are characterized by high levels of salt in the water and soil. Brackish marshes are found in areas where freshwater and saltwater mix, resulting in an intermediate salinity level. All of these synonyms refer to vibrant, dynamic ecosystems that support a diverse range of plant and animal life.