Surface Water Quality in Three Interdunal Ponds, South End Ponds Ecosystem, Cumberland Island, Georgia
Data collection to determine the surface water quality of three shallow interdunal ponds at the extreme southern tip of Cumberland Island National Seashore, Cumberland Island, Georgia has been in progress for more than two years. A brief summary for the interval 14 Apr 88 - 25 Feb 89 was reported previously by Kozel (1989). The principal objective of this project is to obtain, over a five-year period, baseline data on depth and fourteen water chemistry parameters in these ponds. The information obtained will be used to characterize the spatial and temporal fluctuations in surface water quality which are of seasonal and/or annual significance in the ecosystem. Channel dredging in Cumberland Island Sound adjacent to the ponds area has raised concerns within the National Park Service that the confined aquifer beneath the ponds might be breached with subsequent effects on the ponds' water quality; and/or that shoreline erosion might modify the volume of sound water known to enter two of the ponds on high spring tides. Interdunal ponds have received little scientific attention (Odum and Harvey, 1988), but study of the South End Ponds of Cumberland Island is especially important because the endangered wood stork, Mycteria americana, forages on fishes and amphibia in them. Water quality affects the availability of such forage organisms for the birds. This paper reports the results of data collected on depth and fourteen water chemistry parameters in the three South End Ponds from 14 Apr 88 - 26 May 90. Recently, Cofer-Shabica, and others (pers. comm., 1990), have begun to gather data on groundwater hydrology in the ponds' area and this information, combined with the surface water chemistry data, should provide a fair description of the hydrology and water chemistry of the South End Ponds ecosystem.