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 

 which are not found in a natural sedimentary bottom area. The soUd 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 slielter and food for additional 

 species. 



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



Proceedings 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 (also Reprint 78-12, U.S. Army, 

 Corps of Engineers, Coastal Engineering Research Center, Fort Belvoir, Va., Nov. 

 1978, NTIS AD No. A062 304). 



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 guidelines for creating and stabiUzuig foredunes with vegetation. 

 The guidehnes 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. PARR, T., DIENER, D., and LACY, S., "Effects of Beach Replenishment on the 



Nearshore Sand Fauna at Imperial Beach, CaUfornia," MR 78-4, U.S. Army, Corps 

 of Engineers, Coastal Engineering Research Center, Fort Belvoir, Va., Dec. 1978, 

 NTIS AD No. A067 308. 



This study evaluates the changes in intertidal and shallow subtidal sand-bottom infaunal 

 populations in response to the addition of approximately 765,000 cubic meters of dredged 

 material added to an eroded beach at Imperial Beach, California. A sampling design utilizing 

 small sampUng units and extensive replication was effective in generating rehable numerical 

 estimates of infaunal densities and diversity. 



The dredged material had a high proportion of fine material with lesser amounts of shell 

 fragments. Fine sediments were rapidly transported offshore while shells persisted on tlie 

 beach. Measured beach effects were short term (5 weeks or less), involving increases in 

 abundance mostly of motile crustacean species which brood tlieir young. Planktonic 

 recruitment of polychaetes was evident during this period. 



As the fine sediments worked offshore, silt and fine sand fractions increased in the 

 bottom sediments. At subtidal depths, there was a positive correlation between the silt-clay 



