Salt marshes occur on low wave -energy shorelines north of the range of the mangroves and among the mangroves in may areas of south Florida. Salt marshes also extend up into tidal rivers. Many salt marshes are dominated by one plant, usually cordgrass of black rush, The species existing in any one area depend on the degree on inundation by tides and the salinity of the water. Salt marshes often blend gradually with freshwater marshes, forming a transition zone of salt water and freshwater plants. Salt marshes harbor large numbers of invertebrates which are fed upon by many of the higher animals of the marsh and estuary.
Birds are particularly numerous in and around salt marshes.
Rails, egrets, gulls, terns and seaside sparrows depend on the marsh for food, The diamondback terrapin, salt marsh snake, mink, otter raccoon are other characteristic animals.