sparsely vegetated. These authors believe that a foredune zone exists, consisting of low, 

 unconnected hummock dunes, and that during storm surges, the island is uniformly 

 overwashed, and water flows between the dunes and across the island with the result that 

 wave energy is rapidly dissipated. With extremely high surges, large waves occasionally 

 succeed in eroding completely the low-lying foredunes, and carry sediment across the island 

 into the salt marshes of the bay. Overwash is considered important for marsh formation and 

 in allowing tiic barrier island to retreat and maintain its level during the currently rising 

 Atlantic coast sea level. They believe that an artificial dune line does not simulate the 

 natural condition, and that the net results of such a dune line are: (a) erosion of the beach 

 and loss of fine sediments to sea; (b) narrowing and steepening of the beach; (c) elimination 

 of overwash, resulting in suppression of natural island growth; aiid (d) an undesirable 

 succession of plants behind the dunes, allowing less salt-tolerant species to become 

 dominant, which could result in serious denudation should overwash eventually occur. 

 Godfrey and Godfrey (1972) and Dolan (1972a, b) cast serious doubts on the wisdom and 

 value of constructing artificial dunes on east coast barrier islands, and state that such a 

 beach and dune stabilization program may be detrimental to the long-term equilibrium of 

 these barrier islands. 



These conclusions do not seem applicable to the northern half of Padre Island, nor to 

 Mustang Island. The present condition of these islands, even after more than a century of 

 human abuse, is generally a well developed vegetated foredune ridge, and a wide grassland 

 prairie to the lee. In a schematic diagram of the effects of hurricane surges on northern 

 Padre and Mustang Islands, McGowen, et al., (1970) shbwed that surge is channeled through 

 old permanent passes (e.g., Corpus Christi Pass), which partially heal between storms. 

 During severe storms, such as Hurricane Carla, new channels are cut at other weak locations, 

 and foredunes act as an effective barrier. In two extensive areas of well developed foredunes 

 (South Bird Island Quadrangle, and central Padre-Big Shell), few washovers exist, even from 

 Carla. Here, the effects of Carla on this natural system were as described by Dolan (1972a), 

 and Godfrey and Godfrey (1972) as "unnatural," i.e., the cutting back or erosion of the 

 dune face from 50 to 100 feet or greater, without broad overwash. The beach was planed 

 off to a long and gradual slope (without a berm) with considerable loss of sediment 

 (McGowen, et ah, 1970; Davis, 1972). However, the healing process of the foredune and 

 backshore is rapid. McGowen, et al., (1970) stated: "Observations of the beach zone shortly 

 after the passage of Celia indicated that sand was being transported landward and that the 

 normal beach profile was already being restored. 1 ' 



By 1974, the foredunes have largely healed by a shoreward migration from this erosional 

 cut. The process is adversely affected by the constant and heavy vehicular traffic on 

 Mustang and northern Padre Islands, which prunes off the shoreward-growing rluzomes of 

 dune-forming plants and kills emergent seedlings. The most natural foredune system is 

 probably along a 4-mile stretch of beach on the national seashore which has been closed to 

 vehicular traffic since 1968. Backshore vegetation in this area has migrated shoreward 100 

 to 200 feet farther than contiguous areas north and south where traffic is heavy. 



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