PROPAGATION AND USE OF SFAETINA ALTEENIFLORA FOR 

 SHORELINE EROSION ABATEMENT 



by 



W. W. Woodhouse, Jr.^ 

 E. D. Seneca, and S. W. Broome 



I . INTRODUCTION 



This report contains the results of experiments in the use of 

 marsh vegetation to protect eroding shorelines, a laboratory study on 

 mineral nutrition of Spartina altemi flora , and an additional year of 

 monitoring several trials previously described by Woodhouse, Seneca, 

 and Broome (1974) . They reported on the role and importance of salt 

 marshes, the biology of Spartina alterni flora , and the characteristics 

 of the North Carolina coast. Kadlec and Wentz (1974) also provide 

 additional background information. 



II. PROCEDURE 



1. Experimental Sites . 



The work started in 1974 was mostly near Pine Knoll Shores and the 

 Pine Knoll Shores Golf Course. Pine Knoll Shores is a residential 

 development along the south shore of Bogue Sound, about 6 miles west 

 of Morehead City, North Carolina. In this vicinity, the shore lies 

 approximately east to west, the fetch is 1.5 miles to the north, 3 

 miles to the northwest, and 4 miles to the northeast. Tidal range is 

 around 2 to 2.5 feet plus frequent substantial wind setup. Substrate 

 is sandy (99.5-percent sand, 0.2-percent silt, 0.3-percent clay) with 

 some peat patches from old marsh surfaces. The intertidal zone of 

 most of this shoreline was a Spartina altemiflora marsh before devel- 

 opment. During development a channel was dredged parallel to and about 

 100 to 150 feet offshore from the present high tide line. The dred- 

 ged material was deposited along the waterfront lots, covering and 

 killing the marsh. Shoreline recession followed development, and in 

 1973 a concrete pile bulkhead was installed, just above the existing 

 high tide line (Fig. 1). Erosion continued, causing concern by the 

 owners as to the long-term stability of the bulkhead. This concern 

 prompted the use of the area for experimental planting in 1974. 



The Pine Knoll Shores Golf Course is on the sound shore, about 1 

 mile east of the Pine Knoll Shores experimental site. The shoreline 

 differs from the latter; it has not been bulkheaded and patches of 

 marsh exist with an eroding shoreline between the marsh patches. 



These new sites are exposed to northerly winds which create tur- 

 bulence and affect water levels. Strong northwest winds produce low 

 water while winds from the northeast raise water levels. The plant- 

 ings on these sites were subjected to rigorous wave action. 



II 



