Barnacles 
Balanus sp. 
Isopod Crustaceans 
Cyathura sp. 
Chiridotea coeca 
Erichsonella attenuata 
Amphipod Crustaceans 
Gammaridae 
Decapod Crustaceans 
Mud Crab (Xanthidae) 
Blue Crab (Callinectes sapidus) 
Ascidians 
Sea Grapes (Molgula manhattensis) 
Waterfowl 
The brackish estuarine bays are the most 
important waterfowl habitat in the Upper 
Chesapeake region. Between one-half and 
three-fifths of the late fall and winter popula- 
tion occurs in this habitat and large numbers 
of waterfowl also are present in early fall 
and early spring. Unusually large populations 
of Black Ducks breed in the Chester River - 
Eastern Bay area, and fair numbers are 
found along the Choptank River. Characteristic 
species of transient and wintering waterfowl 
are: 
Primary Species 
Whistling Swan 
Canada Goose (local) 
Mallard (local) 
Black Duck (local) 
American Widgeon 
Redhead (local) 
Canvasback 
Lesser Scaup 
Common Goldeneye 
Ruddy Duck 
Secondary Species 
Pintail (local) 
Green-winged Teal 
Blue-winged Teal 
Ring-necked Duck 
Greater Scaup 
Bufflehead 
Oldsquaw 
White-winged Scoter 
Red-breasted Merganser 
American Coot 
Large numbers of Canada Geese, Mallards, 
Black Ducks, and Pintails concentrate in the 
brackish estuarine bays that are adjacent to 
the large agricultural fields along the eastern 
shore of Chesapeake Bay in the Chester River, 
Eastern Bay, and Choptank River areas, Else- 
where these species are scarce or local. In 
the agricultural areas, the birds feed both in 
the grain fields and in the shoalwaters. They 
usually roost on the bays, but occasionally 
roost on artificial impoundments that are 
scattered among the farm lands. Great flights 
frequently trade back and forth between the 
feeding and roosting grounds at dawnand dusk. 
Whistling Swans, American Widgeons, vari- 
ous diving ducks, and American Coots usually 
10 
feed and roost on the bays and are not greatly 
influenced by the agricultural areas. American 
Widgeons do occasionally feed in nearby grain 
fields. Canvasbacks are fairly evenly dis- 
tributed on the brackish estuarine bays, but 
Redheads concentrate in the areas of the 
eastern shore. Lesser Scaup and Ruddy Ducks 
are much more numerous along the western 
shore and in the Potomac and Patuxent areas. 
Canvasbacks, Lesser Scaup, Common 
Goldeneyes, and Ruddy Ducks are the prin- 
cipal waterfowl on Fishing Bay and the Nan- 
ticoke River, where submerged plants are 
scarce. All of these can feed to aconsiderable 
extent on animal food. Canada Geese and 
Black Ducks occasionally use these waters 
as sanctuaries, when they have been driven 
out of the surrounding marshes by excessive 
hunting or extensive ice formation. 
Results of sample counts in brackish estua-~ 
rine bays are shown in table 7. Approximately 
27.5 square miles were covered, The popula- 
tion densities of waterfowl within a quarter 
mile of the shore ranged from about 1,700 to 
12,500 birds per square mile. 
The gullet and gizzard food contents of 372 
waterfowl collected in brackish estuarine bays 
were examined. The major waterfowl foods, 
in order of importance, were widgeongrass, 
corn (illegal bait or from nearby grainfields), 
the bivalve Baltic macoma (Macoma balthica), 
claspingleaf pondweed, and mud crabs (Xan- 
thidae), eelgrass, and the little surf clam 
(Mulinia lateralis). 
SALT ESTUARINE BAYS 
The total area of salt estuarine bays (fig. 2) 
in the Upper Chesapeake region amounts to 
approximately 923,000 acres and includes 
about 196,000 acres that may be classified 
as shoal waters. This habitat extends into 
the Upper Chesapeake region to southern 
Kent Island on the eastern shore and to the 
Shadyside peninsula on the western shore, 
It includes Pocomoke Sound, Tangier Sound, 
Big Annemessex River, Manokin River, Monie 
Bay, Honga River, Tar Bay, Herring Bay, and 
the mouths of the Nanticoke River, Fishing 
Bay, Little Choptank River, Choptank River, 
Eastern Bay, Patuxent River, and Potomac 
River. 
Vegetation 
Submerged aquatic plants occur chiefly at. 
depths of 8 feet or less at mean low tide. 
Eelgrass, widgeongrass, and sea-lettuce are 
most widely distributed. Sago pondweed is 
common locally, and is especially abundant 
in moderately saline areas such as Tar Bay 
and the Honga River, and the vicinity of 
Bloodsworth Island. Horned pondweed and the 
green alga Enteromorpha are present as 
