south of the advancing disposal path in June and 5 weeks after depo- 

 sition in July. Significant increases in total abundance were noted 

 (Fig. 20). Station B (survey IV) densities were significantly greater 

 (p<.05) than those at the other intertidal stations in any season 

 (Figs, 18 to 21). This strongly suggests an enhancement effect from 

 the recent beach deposits. Elevated numbers at station B were pri- 

 marily due to increases in motile crustacean species. Possibly, they 

 behavioral ly responded to factors associated with introduced bay 

 sediments (e.g., dissolved and particulate organics, increased fine 

 sediments, etc.). 



Many of the prevalent crustacean species such as SynoheXidiym sp. 

 (undescribed oedocerotid amphipod) carry their eggs and release 

 miniature adults. Therefore, these increases at station B were pri- 

 marily a result of the presence of adults, as beach population dynamics 

 may largely reflect behavorial responses of adults and release of 

 broods in selected areas. Less dramatic increases in polychaete 

 numbers were observed at station B during survey IV. These primarily 

 recruit from the plankton, and their settlement was not impaired. 

 Individuals were generally aggregated in their distribution (Table 8). 

 Considering the behavorial attributes of the species, this was not 

 unexpected. 



b. Intertidal Diversity . Statements concerning diversity refer 

 to patterns of the density of species per sample and total species 

 collected at a site. Diversity indices which combine abundance and 

 species richness into a single index were not used as they can be mis- 

 leading. 



Species density (number per sample) generally followed a 

 pattern similar to abundance (Figs. 22 to 25, Table 12). Significant 

 differences (p<.05) existed between stations before dredge disposal. 

 These were similar to abundance patterns in relation to season. 

 Winter storm periods reduce species density on the beach. 



As with abundance, an increased number of species and species 

 density was observed at station B during deposition and 5 weeks later. 

 Subsequent to this, density decreased between July and November (surveys 

 IV and V) at stations A and B. However, at the southern control station 

 C, species density increased (Fig. 25). This was probably a result of 

 increased habitat complexity at station C due to the development of a 

 complex beach flat area (Fig. 4). Total numbers of species collected 

 per survey at beach stations do not indicate a significant impact by 

 beach replenishment (Table 12). 



Fifty-six species were collected intertidally during the study. 

 The first survey at three stations collected about half of these. 

 This diversity is considerably higher than the total (n = 33) from 



