o 



CO 



< 



CO 

 < 



AL 2. Mobile Delta. Acreage: 65,000 estimated. 



Location: Mobile and Baldwin counties; Fairhope, Tensaw, and Bay Minette 

 quadrangles; just N of Mobile; reached via U.S. 90, 98, and 3 1 . 



Description: The Mobile Delta is that area in southern Alabama extending from 

 the open Mobile Bay to the union of the Alabama and Tombigbee rivers, which 

 is a distance of about 40 miles in a straight line. It is about 10 miles wide and, 

 unlike a typical delta, is hemmed in on both sides by high land. Approximately 

 the lower one-quarter is treeless island marshes and bays, while the upper three- 

 quarters is a chain of rivers, bays, bayous, and extensive swamp with a thick 

 growth of trees such as black gum, white bay, cypress, red maple, tupelo gum, 

 ash, cottonwood, red bay, and willow. The lower third of this wetland complex 

 is considered one of the finest natural marshes in the country. It is affected by 

 salinity. In the upper bays the salt content varies from to 0.01 ppt in the spring 

 months and from 1 to 3 ppt in the late summer and fall months. Submerged, 

 floating, and emergent vegetation is typical. The most important in order of 

 their abundance follows; bushy pondweed (Najas); potamogeton (Potamogetun 

 pusillus and sp.); wild celery (Vallisneria); water star-grass (Heteranthera); 

 muskgrass (Characeae); coontail (Ceratophyllum); horned pondweed 

 {Zannichellia), and water hyacinth (Eichornia). Tidal emergents and high marsh 

 vegetative species in order of their abundance are as follows: alligator weed 

 (Achurantus); common cane {Phragmites); cattail (Typha); cutgrass 

 (Zizaniopsis); giant bulrush (Scirpus); duck potato (Sagittaria); feather grass 

 (Panicum); saltreed grass (Spartina); three-square (Scirpus); and cowpea 

 ( Vigna). Upper reaches of the area are dominated by swamp bottomland forests. 



References: Lueth, F. X.1963. Final report of Pittman-Robertson Project 7-R, 

 Mobile Delta waterfowl and muskrat research; Baldwin, W. P. 1957. An in- 

 spection of waterfowl habitats in the Mobile Bay area; Beshears, W. Walter, 

 Jr. Alabama's estuarine areas; Beshears, W. Walter, Jr. Work plan V, Job V- 

 F, Mobile Delta vegetative study (Progress report — not for publication); 

 Beshears, W. Walter, Jr. A statement on the Mobile Delta (Prepared -as 

 testimony for the public hearing to establish water quality standards for streams 

 in Alabama); Beshears, W. Walter, Jr., and I. B. Byrd. 1959 Alabama's 

 estuarine areas-Mobile Delta area. Ala. Conserv. 30(6):7-10. 



Encroachments: Industrial pollution (paper mills, aluminum ore depository, 

 chemical plants, sewage). Shell dredging. Highway I- 10, increased commercial 

 development along Battleship Parkway. 



Ownership: Marsh, open water, and bay bottoms, 45,000 acres, state of 

 Alabama; 20,000 acres, private. 



Data source: W. Walter Beshears, Jr., Alabama Department of Conservation, 

 Montgomery, Ala. 36100. 



Other knowledgeable persons: Neil Hotchkiss, BSFW, Patuxent Wildlife Research 

 Center, Laurel, Md. 20810. 



Map on following page 



