— FORT MACON 
ee EMERALD ISLE 
-— NOURISHMENT 
NUMBER PER m@ 
* 
- 
oor” 
Figure 20. Seasonal variation in the density of #. talpotda popu- 
lations at the nourishment beach at Fort Macon, June 
1977 to August 1978, and the comparison beach at Emerald 
Isle, September 1977 to August 1978. The actual period 
of nourishment is represented by a slashed line below 
the X-axis. 
in May when repopulation was well underway at both beaches. This recuitment 
lag resulted from the failure of adult Hmertta to recolonize at Fort Macon 
(Fig. 21). Only adult Emerita were present on the Emerald Isle beach when 
repopulation began in April. These individuals had overwintered offshore and 
were returning to the beach where they would breed. As spring progressed, a 
greater proportion of the population was contributed by new recruits in the 
lower size classes. These smaller individuals represented recruitment cohorts 
from pelagic larval stocks or the young of the year. The first individuals 
to arrive on the Fort Macon beach were not the overwintering adults but the 
young of the year juveniles from pelagic larval stocks. While comparative 
density data for June (Fig. 20) indicated that mole crab densities were similar 
for both beaches, the size class composition was drastically different (Fig. 21). 
Where the Emerald Isle demographic table (Fig. 21) displays a complex assort- 
ment of size classes representing at least two year classes, the Fort Macon 
table (Fig. 21) shows only several cohorts of young of the year crabs. 
39 
