Tidal Marshes

The tidal marshes of the Chesapeake Bay's shallows are border habitats that connect shorelines to forests and wetlands. Just like wetlands and underwater bay grass beds, tidal marshes provide food and shelter for the vast array of fish, birds, invertebrates and other animals that dwell in shallow waters.

There are three types of tidal marshes found along the Chesapeake Bay:

• Freshwater marshes of the upper Bay
• Brackish marshes of the middle Bay
• Salt marshes of the lower Bay

Freshwater Marshes

The Chesapeake Bay's tidal freshwater marshes support a greater diversity of plant species than its salt marshes. Freshwater marshes are filled with a variety of emergent plants that reach the water's surface, including arrow arum and narrow-leaved cattails.

Freshwater marshes are important because they:

• Provide a home for frogs, muskrats, marsh-nesting birds and a host of other animals.
• Help control flood waters
• Keep surrounding waters clean by trapping and filtering nutrients and sediments.

Brackish Marshes

Marshes that grow along the brackish waters of the middle Chesapeake Bay mark the transition from freshwater marshes to salt marshes. Cattails and three-squares are two types of plants that grow in brackish marshes and provide food and habitat for mammals, reptiles and many different types of birds. The invasive plant phragmites is also a resident of brackish marshes.

Salt Marshes

Salt marshes are wetlands dominated by cordgrass, also called Spartina. They are one of the most productive plant communities on earth. Salt marshes are located above and below the high tide line.

• Low marshes are regularly flooded by the tides. The tall form of smooth cordgrass grows here. Low marshes provide critical habitat for juvenile fish, as well as shrimps, fiddler crabs, marsh crabs, marsh periwinkles and ribbed mussels.
• High marshes are irregularly flooded by strong winds or exceptionally high tides. Three-squares, saltmeadow cordgrass and the short form of smooth cordgrass grow here.