(1) Resident populations of the crabs in the nearshore could have 
been buried or forced to leave the area in response to greater turbidity 
associated with the nourishment procedure. 
(2) Changes in the offshore bar system and beach slope could make 
approach to the beach physically difficult or hazardous due to increased 
exposure to predators. 
(3) Reduced availability of prey organisms may have caused the 
crabs to move elsewhere in search of food. 
If the resident populations of these large, highly mobile crabs were 
destroyed or forced to move as a result of beach nourishment, recruits from 
Bogue Banks and Shackleford Banks or from pelagic larval stocks would be 
expected to recolonize soon after nourishment ended. In fact, recruitment from 
elsewhere did not occur. Population estimates for all portunid crabs remained 
low even 2 months after nourishment had ceased. Thus, although resident popu- 
lations of portunid crabs were lost as a result of beach nourishment, some 
factor other than the direct effects of nourishment prevented rapid recovery. 
The beach slope became much steeper after nourishment, and the plunge zone 
for the waves was often directly adjacent to the swash zone thus making feeding 
portunids in the swash zone easier prey for nearshore predators. Also, the 
high concentrations of large shells and shell hash in this zone would have made 
burrowing by the larger crabs almost impossible. These changes in the surf 
zone would have produced conditions generally unfavorable to portunid crabs and 
may have caused them to move elsewhere in search of better habitat. 
The most likely explanation for the low density of portunid crabs in the 
surf zone after cessation of nourishment is that their principal food source 
(Z. talpotda and Donax spp.) had been severely depleted. 
The following young adult fish and fry were encountered in high numbers in 
the surf zone throughout the study period: silversides, Mentdia menidia; 
whiting, Menttctrrhus spp.; summer flounder, Paraltchthys dentatus; pompano, 
Trachtnotus carolinus; croaker, Mtcropogon undulatus; spot, Letostomus xanthurus; 
and cravelle jack, Caranx htppos. Although the importance of fish as carnivores 
in the surf zone has been firmly established (Anderson, et al., 1977), the 
scope of this project did not allow detailed study of these fish. However, 
more than 100 examinations of gut contents were performed during this study, 
and all fish examined had either #. talpotda or Donax spp. present in signif- 
icant amounts in their stomachs. Leber (1977) has reported similar results 
for the same study area. 
Although a number of ghost crabs were encountered in the surf zone (Fig. 
17), their actual feeding activity there was minimal. Most feeding by the 
ghost crabs occurred in the swash zone and those ghost crabs found in the surf 
zone were usually wetting their gills. 
4. Special Studies During the Nourishment Process. 
a. Physical Studies. Rosenberg (1977) reported that one of the effects of 
dredging was an increase in concentration of mercury, cadmium, copper, lead, 
nickel, and zinc both in the water column and in the benthic fauna. Three 
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