Sloughs
Fresh water ponds, called sloughs, are found frequently on Georgia’s barrier islands between dune ridges. On Cumberland, Georgia’s largest barrier island, for example, the most prominent of these sloughs, or ponds, are Lake Whitney, the Sweetwater Lake complex, Johnson’s Pond, Ashley Pond and Willow Pond. Smaller sloughs can be found on the island, depending on the season of the year and the amount of rainfall. In total, Cumberland has about a thousand acres of fresh water sloughs. No barrier island sloughs are exactly alike: they vary in size, depth and the acid content of the water. Some dry up in summer; some contain water all year. Plus, each in its own way is undergoing ecological evolution. At times, for example, sand from the dunes on the east side of Lake Whitney has encroached on the dark, clear waters of the lake. Fire, and the intrusion of salt water or hurricane tides are some of the natural occurrences, which may change the ecological balance of a slough and set the environment back to an earlier stage in its development.
Rain is the only source of water for most sloughs, and seasonal variation in rainfall brings about significant differences in life in and around the fresh water. In spring, large numbers of herons, egrets, and other wading birds form nesting colonies in the sloughs. Wading birds fatten on frogs, snakes and fish. A large number of their nestlings fall in the water, providing food for alligators and cottonmouths. Dense populations of these reptiles may build up in sloughs, which have large colonies of nesting birds. Mammals, like otters, are also promised a good food supply. In the fall, sloughs are important nesting and feeding areas for migrating and wintering waterfowl, which feed on pondweed, bushy pondweeds, bulrushes, banana water lily and other aquatic plants. Acorns and other kinds of fruit from adjacent trees also provide much food for these waterfowl. During dry periods, extra stress is placed on wildlife so that the profusion of plants and animals normally found in these wet areas is absent. Alligators, fresh water turtles and most amphibians, such as frogs, toads and salamanders, are dependent on the sloughs for survival. The small sloughs that are periodically dry are especially important breeding places for amphibians because of the absence of predatory fish.
Regardless of their size or location, however, each barrier island slough plays a major role in maintaining some of the most interesting wildlife on the islands.