The study monitored this beach (Fort Macon) and a comparison beach which did 
not receive nourishment (Emerald Isle) before, during, and after the Fort Macon 
nourishment activities. The primary objectives of this study were: 
(1) To establish base-line quantitative data on community structure 
and seasonal variation among the biota inhabiting the intertidal zone of 
a high-energy sandy beach; 
(2) to determine the effects of beach nourishment using dredged 
materials on the intertidal macrofaunal community of a high-energy beach; 
and 
(3) to make recommendations concerning the implementation and envi- 
ronmental advisability of beach nourishment with dredged materials. 
The high-energy sandy beach environment is harsh, characterized by great 
variations in various abiotic ecofactors, The fauna of the intertidal zone is 
highly mobile and responds to stress by displaying large diurnal, tidal, and 
seasonal fluctuations in population density. Biological diversity is kept low 
and, thus, community structural and functional relationships are kept simple. 
The high-energy psammolittoral community is made up of Hmertta talpotda, the 
mole crab; Donax parvula and Donax vartabilts, coquina clams; Haustortus 
canadensis, an amphipod; Scolelepits squamata, an indirect selective deposit- 
feeding spinoid worm; Talorchestta megalopthalma and Amptporeta virginiana, 
amphipods; Chtrodotea caeca, an isopod; and Wephyts picta, a deposit-feeding 
polychaete (listed in order of decreasing abundance). There is little chance 
for competition because every member of this community except #. talpotda and 
Donax spp. occupies a different trophic or spatial niche. Hmertta talpotda 
and Donax spp. are the dominant organisms in the intertidal zone where they are 
major sources of secondary production. The coexistence of these two species 
within the same trophic and spatial niche is mediated both by the rigorous 
environment and by predation. Migrating consumers responsible for this preda- 
tion include: fishes of both commercial and sport interest, subtidal portunid 
crabs, shore birds, and ghost crabs. 
1. The Environmental Significance of Beach Nourishment. 
Beach nourishment was found to affect organism density and community struc- 
ture both during and after nourishment. Organisms on the beach at the time of 
nourishment were killed; however, the effects of nourishment were not limited 
solely to the beach or to the nourishment area. Other effects included: 
failure of adult intertidal organisms to return from their nearshore-offshore 
overwintering refuges, reductions in organism densities on adjacent unnourished 
beaches, and inhibition of pelagic larval recruitment effort. The nourished 
beach recovered slowly. During this period, secondary productivity remained 
low and measures of community structure indicated low diversity. Low secondary 
productivity resulted in a reduced utilization of nourished beach by migrating 
consumers of commercial and sport interest, 
2. Recommendations. 
Larval recruitment appeared to be inhibited by the greater water turbidity 
associated with the nourishment operations. Further study is needed to deter- 
mine the mechanism of larval inhibition by suspended materials and threshold 
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