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


Despite the obvious hazards of building too close to the beach, new hotels, such as the Holiday Inn on Wrightsville Beach shown in Fig. 106, are being constructed all along the Atlantic shoreline and are inviting disaster from the next hurricane. After a short time, the beach retreats and the owners of beach property then lobby for a publicly funded beach nourishment project (Fig. 107) to protect their private holdings which, in most cases, should never have been built there in the first place. Thus starts a never-ending cycle of erosion and temporary engineering solutions for a situation that will continue to worsen.

Fig. 106. A resort motel under construction at Wrightsville Beach, North Carolina. The high tide line is in the foreground.

Fig. 107. The eroded scarp typical of beaches artificially built of fine sediment dredged out of the sound.

On the western end of Bogue Banks, acres of prime maritime forest, festooned with Tillandsia usneoides, were cleaned off to build a four-lane highway (Fig. 108). Near the middle of the island, one developer has gone so far as to cut nearly through the dry land with a channel from the sound side to provide boat access to a trailer park, thus inviting the formation of a new inlet by the next big hurricane.

Fig. 108. Road cut through an outstanding maritime forest on western Bogue Banks.

All these developments must be supplied with water. Deep wells on the islands produce water that is unpleasantly sulfurous. Shallow wells sunk into the surface water table result in better water, but the water table floats as a lens resting on and surrounded by salt water, and is derived entirely from rainfall. If too much fresh water is removed, the salt water moves in more or less permanently. This is a widespread difficulty with coastal water supplies.

That those who use the developments may be spared the problem of mosquitoes, some of the Outer Banks' salt marshes have been ditched and, in the past, sprayed. This removes a small amount of the marsh itself from estuarine productivity, and may have other ecological effects such as drying out the marsh so that more terrestrial and less productive species can invade. However, the overall result may not be entirely negative, since there are suggestions that nutrient exchange and productivity output may be improved by ditching (Fig. 109).

Fig. 109. Salt marsh mosquito ditches in eastern North Carolina, The ditches are 6 ft. (1.8 m) wide, very deep, and built without regard for natural drainage patterns.

Marshes have also been used as a source of beach fill and barrier dike material, as well as being filled for various development purposes (Figs. 110 and 111). Such ecologically disastrous operations should presumably no longer be permitted on Federal lands, but they are still being carried out at alarming rates on private land, despite efforts to protect these resources. Dredging and filling of marshlands have been all too common activities behind the more easily accessible barrier islands. The size of Cape Lookout, however, has been greatly increased in recent years, and its shape changed, partly because of the jetty which was built there in 1915 (Figs. 129 and 130).

Fig. 110. This boat-launching bay was made by excavating a salt marsh to get fill to shore up an eroding dune line. Cape Hatteras National Seashore is in the background. The already vulnerable island has been further narrowed.

Fig. 111. Marsh adjacent to the same bay is being filled to make a parking lot for the boat launchers. This sort of thing would presumably not be done today.

The effects of technology and development on barrier beaches are graphically illustrated when natural beaches are compared to highly modified ones, where erosion has become a problem and various techniques are being used to "control" barrier-island retreat. Figure 112 is an aerial view of the still undeveloped Cape Lookout beach system, where the only major human impact consists of the lighthouse and a few buildings on the back side of the Cape. Storm tides can sweep across Cape Lookout but do no real damage, and the beach retreats according to natural processes. Here beach erosion is not a problem.

Fig. 112. Cape Lookout Lighthouse. Thirty or forty years ago the Hatteras Lighthouse was separated from the ocean by a similarly side berm. (Photo by R. Simpson.)

In contrast, Figs. 113 and 114 show several stages in the degradation of the beach at Cape Hatteras, and consequent attempts to control erosion. The Cape Hatteras region was once much like Cape Lookout, with a wide beach and no developments near the beach. Historically, the section of the Hatteras beach near the lighthouse has experienced continuous retreat, but when the lighthouse was built in the mid-1800s, the beach was wide. Over the years the beach has retreated closer to the lighthouse. The greatest problems came in recent years, however, following the creation of a "stabilized" dune line on the beach. Private land was quickly developed with summer houses and motels, and in addition, a U.S. Navy facility was built just north of the lighthouse. The man-made dunes did not solve the erosion difficulties, but they have been increasingly attacked by waves, with obvious threat to the structures behind.

Fig. 113. (A) In 1969, Cape Hatteras Lighthouse and the naval facility just beyond were in serious danger from the sea. The white strip in front of the lighthouse is plastic bags filled with sand. Note the narrowness of the beach, the irregularity of its outer edge, and the artificial dunes in the foreground. (Photo by Cape Hatteras National Seashore.) (B) The beach after groins were built in 1970. The groins have captured sand moving down the beach and the lighthouse is temporarily safe, but note how the artificial dune has been cut away by erosion on the downdrift side of the groin. (Photo by Cape Hatteras National Seashore.)

Fig. 114. (A) Looking south along the Hatteras Island beach in 1969. Note motels and private houses just behind the dune line, (Photo by Cape Hatteras National Seashore.) (B) The same just after a bad storm in November 1971, cut away much of the dune line. There has been a breakthrough with overwash; the waves are very close to the motels; the objects on the beach in the foreground are the remains of plastic bags filled with sand to hold back the sea. (Photo by Cape Hatteras National Seashore.) (C) To remedy the situation in B, an experimental beach nourishment project was begun in February 1972, with sand pumped from Hatteras Point. The erosion problem in front of the motels is temporarily relieved. (Photo by Cape Hatteras National Seashore.)

As the stabilized dunes broke down, various temporary remedies were initiated, such as placing bags of sand at the toe of the dune in front of the lighthouse (Fig. 113A). Following the failure of these attempts, three groins were built opposite the naval facility and the lighthouse, resulting in predictable changes in the beach system (Fig. 113B). The groins did indeed stop migration of sand down the beach from the north and widened the beach, but the downdrift side of the structures was then starved for sand, and here erosion was greatly accelerated. Concern was then raised about the historic site of the former lighthouse, south of the present structure, which was soon threatened by more rapid erosion, not to mention the general loss of National Seashore land south of the groins. Thus, while the groins may have slowed the erosion at the lighthouse, they hastened the loss farther down the beach and changed the whole shape of the shoreline.

With erosion continuing to the north of the lighthouse (which soon took on the appearance and exposure of a headland at sea), and periods of overwash through what remained of the dune into the developed areas (Figs. 114A and 114B), a plan was devised to artificially restore the beach. Sand was pumped from an accreting part of Cape Hatteras south of the lighthouse to the eroding sections on the north side (Fig. 114C).

This beach "restoration" is another type of environmental tampering which has both positive and negative aspects. Dredging fine sediment out of the estuaries and marshes to "nourish" the beach is purest folly, for the material is so fine that it is soon washed away in the high energy environment of the beach (Fig. 107). The beach is "improved" for only a little while, but the sound or marsh from which the fill was taken is damaged permanently. Clearly, the short-term benefits obtained by this operation must be weighed against the longer-term costs of estuarine destruction. Nourishment can be more useful when normal beach sand is moved from accreting to eroding areas, thus putting the sand back into the littoral drift (Fig. 114) or by pumping spoil from inlet dredging onto the downdrift beach. All such operations are expensive in terms of initial costs, long-term cost, and hidden ecological cost. They are clearly only temporary solutions, and must be carefully evaluated as to the value of the structures they are designed to protect. In many cases it might be cheaper and more desirable to remove or relocate the threatened buildings than to continuously rebuild the beach by artificial techniques.

The most practical "use" that can be made of the Outer Banks is recreation. A great deal of fishing, shellfishing, hunting, swimming, and just plain enjoying the outdoors has taken place on both developed and undeveloped islands over the years. There is nothing intrinsically destructive to the environment about these activities as long as the participants follow the rules on catch limits, and if they can enjoy themselves without the help of a lot of environmentally destructive development. Unfortunately, a good many people have shown no respect for the Outer Banks environment and have spoiled a great deal of it for more sensitive visitors. Surf fishing on Core Banks is a case in point. There are a great many camps on the island where the fishermen stay; clusters of them are sometimes surrounded by rings of abandoned cars towed there in an effort to protect the buildings from the sea (Fig. 115). Fishermen bring to the island an old car which they drive up and down the beach until it wears out or gets hopelessly stuck. This in itself does no real harm unless the car is driven over dune grass or through bird nesting grounds, but the car is eventually left to rust on the beach, where it is an esthetic insult and a safety hazard. No one wants to pay to have a valueless vehicle ferried ashore. There are probably over a thousand such hulks on Core Banks (Fig. 116). Most builders of cabins are squatting on the land, since at present most of the land in Cape Lookout National Seashore is owned by the state of North Carolina. Although some people have put up neat, decent little buildings, many of the cabins are unsightly, vermin-infested hovels surrounded by rubbish (Figs. 117 and 118). Such conditions will eventually be remedied by the National Park Service as it takes control of Cape Lookout National Seashore. (Esthetics and health considerations aside, the cabins do show that it is possible to build on the unprotected parts of the islands if one accepts flooding as inevitable; the camps are built mostly on posts and the high water simply flows underneath.)

Fig. 115. A typical fishing camp on Core Banks, with a line of old cars in front to catch sand.

Fig. 116. The cars have started a few small Uniola dunes, but the unsightly array does not help the beach nor does it provide real protection from a major storm.

Fig. 117. A representative scene inside the fishing camp.

Fig. 118. Solid waste and the remains of a feral cat on Core Banks.

<<< Previous <<< Contents >>> Next >>>

Last Updated: 21-Oct-2005