What is a Salt Marsh?

Salt marshes are coastal wetlands that form a transition zone between land and sea. Along with coral reefs and rain forests, salt marshes are among the most productive ecosystems in the world. They provide habitat for wildlife, serve as nurseries for fish and shellfish, store floodwaters and protect our shorelines against storm damage. Salt marshes also act as a natural purifier by filtering pollutants and sediment and by absorbing excess nutrients from streams, rivers and surface runoff before they reach coastal waters and drinking water recharge areas.

Subjected to the daily rise and fall of the sea, the salt marsh environment is constantly changing.  Incoming freshwater from rivers, streams and groundwater mixes with tidal saltwater resulting in frequent and rapid changes in salinity, temperature and water depth within the salt marsh system. Salt marshes are characterized by plants and animals that are adapted to a saline environment. 

Cape Cod salt marshes provide nesting, feeding and breeding habitat for a variety of animals, including rare and endangered species.  Among these are the rare and protected northern harrier, least tern, king rail, river herring, the Massachusetts-listed diamond-backed terrapin and eastern box turtle.