Just like marshes further inland, salt marshes are also wetlands. Salt water marshes occur in places where the land meets the sea, such as barrier islands and other coastal areas. They are exposed to water at different times of the day or year. Sometimes the marsh has little water, sometimes it is dry, and sometimes it is very full of wateralmost like a pond. Their salinity, or salt content, varies depending upon whether they are located right on the ocean or further upstream in the estuary or sound. The water level and salinity level determine which plants and animals make their homes there.
Salt marshes are extremely productive. Microscopic organisms like bacteria, fungi, and algae make their home in the decaying marsh grasses. These decaying plants and micro-organisms are then eaten by fish, worms, and crustaceans, furthering the cycle of decomposition. The plentiful insects provide food for birds and fish.
The vegetation of the salt marsh also provides shelter
from predators, especially for young animals who use the salt marsh as