backed by steep cliffs, while the present study took place on a barrier island 
of low relief. These factors may have influenced the diatom populations some- 
what. 
Quantification of the algal community indicated its population was small, 
leading to the conclusion that it is of minor consequence as a food energy 
source for the beaches studied. 
3. Summary of Analysis of Data from Migrating Consumers. 
a. Migrating Consumers from the High Tide Drift Line. Two organisms were 
observed commonly along the high tide drift line. Talorchestia megalopthalma, 
talitrid amphipods, were encountered sporadically, but never in great numbers. 
This amphipod seemed to be more prevalent during times when the normally 
dominant ghost crabs (Ocypode quadrata) were absent. 
Ghost crabs were the most prevalent higher order consumer above the swash 
zone except during winter when they remained quiescent in their burrows. The 
density of ghost grabs increased as temperatures rose in spring (Fig. 15). 
The peak prenourishment population estimate of 280 crabs per linear kilometer 
of beach occurred in July 1977. Counts gradually decreased until winter when 
the crabs became quiescent. 
200 
km 
nourishment 
PER 
100 
NUMBER 
MONTH 
Figure 15. Annual pattern of ghost crab (Ocypode quadrata) abundance at 
Fort Macon, January 1977 to August 1978. 
28 
