CAPE LOOKOUT Barrier Island Ecology of Cape Lookout National Seashore and Vicinity, North Carolina NPS Scientific Monograph No. 9

GENERAL ZONATION PATTERNS (continued)

IV. Fresh Marshes

Fresh-water marshes are limited on the Outer Banks. They are usually found on islands such as Shackleford Banks, Bogue Banks, and Hatteras, where spit growth has resulted in curving lines of dunes; the depressions between the dunes are cut off from the sea and turn into fresh marshes (Fig. 88). Other fresh-water habitats, such as Mullet Pond on Shackleford, are formed when sand bars or spits build across the mouth of a small bay (Fig. 89). These ponds and marshes often dry up when rainfall is low, but when they are full, they support a wealth of birds, amphibians, small fish (in permanent ponds), and are characterized by marsh plants such as Typha latifolia (cattail), Typha angustifolia (narrow leaved cattail), and Cladium jamaicense (saw grass); also Andropogon virginicus, Juncus roemerianus, J. megacephalus, J. coriaceus, Setaria geniculata, Kosteletzkya virginica (seashore mallow), Sagittaria latifolia (arrowhead), Boehmeria cylindrica (bog-hemp), Hydrocotyle umbellata (water pennywort), H. bonariensis, Ipomea sagittata, Mikania scandens, Dichromena colorata, Scirpus americanus, Fimbristylis, Cyperus, Spiranthes vernalis, Pluchea, Bacopa, Cicuta maculata (water hemlock), Lippia, Centella, Chara (stonewort), Ludwigia (false loosestrife), Polygonum (knotweed), Paspalum floridanum, Cyperus, Eleocharis (spike rush), Samolus parviflorus (water pimpernel), ferns, and many other species.

Fig. 88. Fresh water marsh on Shackleford, between the wooded dunes in Fig. 77 with arrowhead (Sagittaria), cattail (Typha), blackneedle rush (Juncus roemerianus), morning glory (Ipomea), and marsh mallow (Kosteletzkya).

Fig. 89. Mullet Pond on Shackleford, with narrow-leaved cattail (T. angustifolia). This fresh pond was part of the sound in the last century until a bar developed across its mouth.