BUILDING SALT MARSHES ALONG THE COASTS 

 OF THE CONTINENTAL UNITED STATES 



hy 



W, W. Woodhousej Jr. 



I . INTRODUCTION 



1. Natural Marsh . 



A coastal marsh is a herbaceous plant community (plants lacking 

 woody stems) found on the part of the shoreline which is periodically 

 flooded by sact or brackish water. A number of species in the grass 

 family (gramineae) , sedge family (cyperaceae) , and rush family 

 (juncaceae) commonly form coastal marshes. 



Coastal marshes occur naturally in the intertidal zone of moderate 

 to low-energy shorelines along tidal rivers and in bays and estuaries. 

 These marshes may be narrow fringes along steep shorelines , but can 

 extend over wide areas in shallow, gently sloping bays and estuaries. 

 Such lands were extensive and widely distributed along the Atlantic, 

 gulf, and Pacific coasts of the United States before development by 

 man. 



Until recently, these wetland resources have been steadily shrink- 

 ing as they were generally considered useless and viewed as prime areas 

 for agricultural, commercial, and recreational uses and for waste dis- 

 posal. For example, since 1850 an estimated 1,000 square kilometers 

 of wetlands have been diked and filled in California alone (U. S. Army, 

 Engineer District, San Francisco, 1976). 



Destruction of coastal wetlands has lessened as the value of these 

 areas as nursery grounds or sources of primary production (energy) for 

 a high proportion of sports and commercial fishery species (Odum, 1961; 

 Teal, 1962; Odvun and de la Cruz, 1967; Cooper, 1969; Williams and 

 Murdock, 1969) and the need for shoreline protection has become widely 

 recognized. 



Interest has developed in marsh restoration, in the building of new 

 marshes to replace a part of those that have been lost, and in the use 

 of marsh plants to stabilize and protect eroding shorelines. Studies 

 on marsh building were initiated in North Carolina in 1969 under the 

 sponsorship of the Coastal Engineering Research Center (CERC) (Wood- 

 house, Seneca, and Broome, 1972, 1974, and 1976) and later expanded 

 to the Chesapeake Bay (Garbisch, Woller, and McCallum, 1975) and the 

 gulf coast (Dodd and Webb, 1975; Webb and Dodd, 1976). Studies of 

 marsh building along the Pacific coast were undertaken in 1975 (Knut- 

 son, 1975; U. S. Army Engineer District, San Francisco, 1976; Knutson, 

 1976). These studies, and earlier plantings along tidal river shores 

 in Virginia (Sharp and Vaden, 1970), have demonstrated the feasibility 

 of establishing new coastal marsh under a variety of situations. 



