Salinities at both beaches were similar. They were lower (averaging 
around 33 parts per thousand)in late winter, and higher (ranging between 36 and 
38 parts per thousand) during summer. In February and March 1978, while nourish- 
ment was in progress, salinities at Fort Macon reached their lowest (27 parts 
per thousand). This compares with a salinity of 30 parts per thousand at 
Emerald Isle during this time. It could not be determined whether this 
decreased salinity was due to the close proximity of Fort Macon beach to 
Beaufort Inlet or the nourishment activities. 
2. Summary of Analyses of Microalgal Communities. 
Large numbers of living microalgae were never recovered from beach sediments 
by any of the methods tried. No diatoms were located on any of the cured cover 
slips, not even cover slips prepared with the elutriate after sonication. In 
fact, the only living microalgae seen during these observations were a few 
naviculoid diatoms noted on one cover slip before it was cured. These few 
diatoms were lost during the curing procedure and could not, therefore, be 
identified to species. 
Results of these observations indicate that the epipsammic diatom popula- 
tion of these two beaches was very low and was of minor consequence as a food 
energy source for the beaches. These results confirm the reports of others 
who have attempted to quantify the productivity of epipsammic diatoms on ocean 
beaches. Cox (1976) reported that most sandy beaches on exposed coasts support 
a mesopsammic (or interstitial) community and that the biomass of this commu- 
nity is low compared to most cther littoral and sublittoral systems. Steele 
and Baird (1968), in their studies of production ecology on a sandy beach in 
Scotland, reported that the sublittoral part of a sandy beach produced only 
4 to 9 grams of organic carbon per square meter per year. Production on the 
intertidal portion of the Scottish beach was only measured once, but the 
resulting value was so low that they terminated that part of their studies. 
Leach (1970) found sand to be the least productive substrate in the Ythan 
estuary, and estimated its organic carbon production at less than 5 grams per 
Square meter per year. 
Even though Steele and Baird's (1968) production estimates were low, they 
found viable populations of diatoms to a depth of 20 centimeters, well below 
the euphotic zone for sand. Amspoker (1977) found interstitial diatoms on the 
beach at La Jolla, California, to be unstratified and uniformly distributed 
with high diversity. Both sets of researchers attributed the observed distri- 
bution of the diatoms to the constant sorting and mixing of wave action. 
Neither Amspoker (1977) nor Steele and Baird (1968) gave any indication of 
the concentration of interstitial diatoms; however, Steele and Baird (1968) 
did state that the amount of organic carbon under 1 square meter of sand (to a 
depth of 20 centimeters) was 50 grams, 40 percent of which were diatoms. Thus, 
the total production available for cropping was only that part of the 20 grams 
of plant material that could be taken without causing the plant population to 
become depleted. 
Both Amspoker (1977) and Steele and Baird (1968) obviously found more 
diatoms than were found in this study. It may be significant that their studies 
took place on beaches that were slightly more sheltered than the beaches at 
Bogue Banks. Additionally, their beaches were at the base of fjords that were 
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