Carolina Environmental Diversity Explorations
A blackwater river from sea to source · By Dirk Frankenberg
Tidal freshwater section of the White Oak (1)
Figure 11. Freshwater marsh with salt marsh fringe at low salinity area (Photograph by the author. More about the photograph)
Figure 11 is a view of a marsh about 10 miles upriver from the ocean. Here you see black needle rush along the water’s edge along with a new plant, the freshwater sawgrass (cladium jamaicense) growing landward of it. In the background, you see red cedars growing naturally between the freshwater marsh and the pine forest in the background. In this area the water contains salt only on unusually high tides or when strong onshore winds blow up the estuary. The water here is still affected by the tides, though. On rising tides, the water here gets deeper, although most of the time it remains fresh. The rise simply represents the upstream movement of fresh water that had moved seaward on the preceding low tide. This section of an estuary is therefore known as the tidal freshwater section.
