Salt Marshes

Salt marshes are found throughout Florida’s coastal areas, primarily along low-energy shorelines and in bays and estuaries. These ecosystems are characterized by daily tidal flooding and support many specially adapted salt-tolerant plants. Salt marsh vegetation occurs within the marsh between the low and high tidal zones. The flora are composed of a variety of rushes, grasses, and sedges. Florida’s salt marshes are typically dominated by black needle rush (Juncus roemerianus), smooth and salt meadow cord grass (Spartina alterniflora and S. patens), and occasionally sawgrass (Cladium jamaicense). The distribution of these plants across the salt marsh is controlled by the level of tidal flooding; with black needle rush in the highest parts of the marsh, salt meadow cord grass in the areas that receive intermittent flooding, and smooth cord grass found in the lowest and wettest parts of the marsh. Sawgrass is typically a freshwater plant that can tolerate some salt and is usually found along the inland edges of some Florida salt marshes.

Salt marshes are a very important coastal ecosystem and provide numerous ecosystem services for the many species that make use of the habitat (including humans). The plants and algae in salt marshes form the base of the food web and act as a direct food source for some organisms, while others utilize dead and decaying plants in the form of detritus. Along with food, salt marshes provide habitat for the majority of Florida’s commercial and recreational fish in either their juvenile or reproductive life stages. The marshes also support a number of commercially and recreationally important invertebrates including crabs, shrimp, and oysters. Salt marshes protect the coastline by providing protection from storm surge and coastal flooding, and act as natural filters to help improve coastal water quality. The marsh plants can help trap nutrients, pollutants, and sediment, thus keeping these things within the marsh and improving water quality in adjacent bays and estuaries. Despite their high value in terms of ecosystem services, large extents of salt marshes in Florida have been lost to coastal development. Although these ecosystems are now protected, salt marsh loss continues to occur due to the influence of upstream changes in hydrology and associated inputs of excess sediments and nutrients. Additionally, natural drivers such as sea-level rise will reduce the amount of area available as marshes migrate landward, since much of Florida’s coastal inland areas have been developed. Florida’s fisheries are at risk of severe decline without the continued protection, conservation, and restoration of coastal salt marsh habitats.