corresponding depths on the island's revetments. Natural sediments were dominated by 

 polychaete worms (35 percent of biomass and 50 percent of species), small crustaceans, 

 clams, ribbon worms, and brittle stars. 



The construction of Rincon Island has had a major beneficial effect on local ecological 

 conditions. The quarry-rock and tetrapod construction materials offer habitat features 

 wliich are not found in a natural sedimentary bottom area. The solid substratum is 

 colonized by a high diversity of encrusting and attached biota. Many of these are 

 habitat-forming species in the sense that they provide shelter and food for additional 

 species. 



47. KNUTSON, P.L., "Planting Guidelines for Dune Creation and Stabilization," Proceed- 



ings of Symposium on Technical, Environmental, Socioeconomic and Regulatory- 

 Aspects of Coastal Zone Planning and Management, American Society of Civil 

 Engineers, Vol. 2, Mar. 1978, pp. 762-779. 

 Foredunes function as a reservoir of sand to nourish eroding beaches during storms, and 

 as a levee to prevent the inland penetration of waves and storm surges. Dunes are usually 

 created and maintained by the action of beach grasses which trap and hold windblown sand. 

 Erosion wiU occur if this vegetation is damaged by drought, disease, overgrazing, or by 

 waves during severe storms. Damaged or destroyed dune systems can usually be restored by 

 planting beach grasses. 



This paper provides guideUnes for creating and stabilizing foredunes with vegetation. 

 The guideUnes are based on more than two decades of field studies conducted by CERC and 

 others. Specific information is given on recommended plant species, planting techniques, 

 fertilization rates, labor requirements, and expected dune growth rates. 



48. WEBB, J.W., and DODD, J.D., "ShoreUne Plant Estabhshment and Use of a 



Wave-Stilling Device," MR 78-1, U.S. Army, Corps of Engineers, Coastal 

 Engineering Research Center, Fort Belvoir, Va., Jan. 1978. 



The estabhshment and development of smooth cordgrass transplants on a 2-percent 

 slope behind a wave-stiUing device constructed of two tiers of tires strung on a cable were 

 monitored along the north shore of East Bay in Texas. Two previous plantings on the sloped 

 area, the first without wave protection and the second behind one tier of tires, were 

 unsuccessful. After a second tier of tires was placed on top of the original tier, enough 

 protection was provided from waves to allow successful planting. A 0.15-meter buildup of 

 sediment occurred directly behind the barrier. 



Smooth cordgrass survival was approximately 50 percent and over 100 stems per meter 

 squared were counted in some areas 1 year after planting. Density and height of smooth 

 cordgrass increased with increasing hours of inundation. Gulf cordgrass, marshhay cordgrass, 

 and saltgrass survived better than smooth cordgrass above mean high water (MHW). At the 

 highest elevation (0.6 meter above MHW), survival was Umited, regardless of species. 

 Needlegrass rush transplants failed to survive in significant numbers. With adequate wave 

 protection, smooth cordgrass can be estabUshed below MHW in estuarine areas. Gulf 

 cordgrass, marshhay cordgrass, and saltgrass can be used above MHW for shorehne 

 protection. 



