White Oak River estuary

Figure 6. Patches of salt marsh in the high salinity section of the estuary (Photograph by the author. More about the photograph)

Figure 6 is a view of the high salinity, open water area of the White Oak River estuary about 4 miles inland of the mouth. Salt marsh still occurs on the estuary floor, but it is clearly much less extensive than closer to the ocean and its sources of sediment.

One would think that the land runoff would provide enough sediment to allow salt marsh development, but that is not quite the case. The water level you see here is at low tide, and, although it is very shallow, it is not at intertidal level. If you look closely in the right background you will see an eroded sand cliff on the seaward side of a mid-estuary island. This island is part of an old shoreline (see explanation in the Large Sand Volume Barrier Island fieldtrip in this series), but even that relatively substantial sand supply is not enough to create salt marshes here.

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