The impacted intertidal stations, 4.5 months after beach replenish- 

 ment had approximately five times more coarse sand than the intertidal 

 control station. The spatial distribution of coarse sand volume along 

 the beach transect (high waterline to -0.6 meter MLLW) for stations A 

 and C for survey V shows that the coarse sand persisted on the berm 

 and beach slope (Fig. 10). Additionally, the proportion of coarse 

 sand was maximum along the beach face indicating that as waves rework 

 the deposited sediments a part of the coarse sand is carried up on 

 the beach face. At the beach-water interface and proceeding offshore, 

 the sediments are reworked and sorted to the extent that there is no 

 difference between the northern dredge station and the southern control 

 (Fig. 11). 



The large increase in coarse sand found in the sediment samples 

 is correlated with the large aggregations of shells formed by the 

 resorting of deposited sediment which contained 5- to 20-percent shell 

 material. After the winter storms of 1977-78 the beach was again 

 photographed (March 1978) and there was a conspicuous absence of these 

 shell deposits. It is suggested that storm surf has reworked these 

 shell deposits either into smaller fragments or buried them offshore. 

 In March 1978, patches of shells were found in the swash zone beneath 

 an estimated 10- to 20-centimeter overburden of finer material. 



A further measure of sediment modification induced by beach re- 

 plenishment is revealed by the sediment-sorting coefficient, a(^ = 

 (<1>84 ~ '}'16)/2, determined from sediment samples via gravimetric sand- 

 grain analysis. This is a measure of how uniform the sand-grain dia- 

 meter is in a sediment sample. Coefficients of 0.4 to 0.6 indicate well- 

 sorted sand or uniform grain size and constant pore space while values 

 of 0.7 or larger indicate a greater range of sediment diameters and 

 less porous sand with variable pore space. Sediment sorting coefficients 

 for the 3.7- and 6.1-meter stations are shown in Figure 12. There was 

 no change in sediment sorting for the offshore stations. Impacted 

 intertidal stations (A and B) had an increase in both the sorting co- 

 efficient and in the range of coefficients measured (Fig. 13). 



3. Organic Carbon . 



Organic carbon in the sediments is an indication of food source 

 for deposit-feeding infauna. Organic carbon values were generally 

 highest at the 6.1-meter stations, less at the 3.7-meter stations and 

 lowest intertidally (Fig. 14). Intertidally, there was no measurable 

 influence of beach replenishment on the organic carbon content of 

 sediments. However, offshore at the 3.7-meter stations (survey II, 6 

 April 1977) , sediments at station A which were sampled during the 

 dredge-disposal period had a 51-percent increase in organic carbon 

 compared to station B and a nearly threefold increase compared to 

 station C. Station B, survey III (2 June 1977) was impacted by beach 

 replenishment and a 36- and 146-percent increase in organic carbon was 

 found, compared to station B, survey II at 3.7- and 6.1 -meter depths. 

 Organic carbon values remained higher at the impacted stations than at 



38 



