BRACKISH WETLAND: Background

Within the mid-Atlantic Coastal Plain, freshwater, emergent marshes are diverse and occur in both tidal and nontidal areas. Nontidal marshes are found surrounding inland lakes and ponds and along rivers beyond the reach of tides. These marshes are dominated by emergent plants such as cattail (Typha latifolia) and various rushes (Juncus spp.) and sedges (Carex spp.). Tidal fresh marshes are located directly inland of salt marshes, in areas where water movement is influenced by tidal fluctuations but salinity levels are

below 0.5 ppt. These marshes are dominated by emergent plants such as pickerelweed (Pontederia cordata), wild rice (Zizania aquatica), and arrow arum (Peltandra virginica). Brackish marshes occur along tidal tributaries within the transition zone between outer salt marshes and tidal fresh marshes. These marshes are dominated by big cordgrass (Spartina cynosuroides).

Freshwater marshes are widespread within the planning unit but are much less abundant than other wetland types. Nontidal marshes are distributed throughout the region in association with impounded water and the upper reaches of small tributaries. These marshes have increased over the past 20 years due to an increase in reservoir and pond construction. Within the planning unit, tidal fresh marshes reach their highest abundance within the tributaries along the western shore and upper eastern shore of the Chesapeake Bay. Big Cordgrass marshes occur throughout the planning unit where salinity is appropriate.

Maintenance of fresh/brackish marshes is important to the avifauna of the mid-Atlantic Coastal Plain. These marshes provide the primary breeding habitat for several species of waterbirds. In addition, these marshes serve as nursery habitats for a significant portion of the fisheries within the region on which many other species depend.