The haustorid amphipods were the most diverse taxonomic group to occur on 

 the Duck, North Carolina beach. Five species occurred with varying regularity. 

 The genera Haustorius and Parahaustorius were the most common. Haustorius spp. 

 occurred high in the swash zone to subtidal, while Parahaustorius longimerus 

 was mainly subtidal. The other haustorids were mainly subtidal (Table' 10). 



Scolelepis squamata, a spionid polychaete, which is common in high energy, 

 sandy areas (Shelton and Robertson, 1981) was only common in July 1981. This 

 may have been the result of a late spring or early summer recruitment, since 

 most of the individuals were very small. No other species occurred at Duck 

 that were other than incidental (five or fewer occurrences out of a possible 

 84, Table 10). This low number of species, while typical of the ocean beach, 

 is a bit lower than was reported for other beaches (Pearse, Humm, and Warton, 

 1942; Dahl, 1952; Shelton and Robertson, 1981). The maximum species diversity 

 (H') seasonally for the Duck beach- -1.62 in November, 1.56 in January, 1.59 

 in April, and 1.67 in July--was lower than the average diversity reported by 

 Shelton and Robertson (1981) for the surf exposed Texas beaches. Even if the 

 Duck haustorids were considered separately, maximum diversity would not reach 

 the average diversities reported by Shelton and Robertson. 



The Duck ocean fauna formed a single community unit. While Emerita 

 talpoida was the only important species in the swash zone, it also occurred 

 subtidally. This agrees with other beach studies that indicate a single 

 community inhabits the high energy ocean beach environment (Pearse, Humm, 

 and Warton, 1942; Dahl, 1952; Shelton and Robertson, 1981). The Duck beach 

 fauna then was typical of other beaches in this respect. While Knott, Calder, 

 and Van Dolah (1982) found distinct communities in the intertidal and subtidal 

 habitats at beaches around Murrells Inlet, South Carolina, their transects 

 were about 1 kilometer long. Where Knott, Calder, and Van Dolah' s stations 

 were similar to the current study in distance from shore, their data also 

 indicated a single community. 



b. Comparison between 1975-76 and 1980-81 . Matta (1977) surveyed the 

 Duck beach in 1975-76. The present study occupied the same transects and 

 stations as Matta and also employed the same methodologies. It is therefore 

 possible to compare the two studies and establish what changes have occurred 

 in 5 years. Matta' s (1977) data are continually referred to as the early 

 study or the 1976 conditions. 



On the average, temperature and salinity were higher in 1976. The 

 depth was variable for both studies, but stations at the offshore end of the 

 transects were deeper in 1976. The carbonate and organic content of sediments 

 were similar between 1976 and 1981. While sediments appeared to be coarser 

 in the beginning of the 1976 study, there is no overall difference in the 

 grain size between 1976 and 1981. Sorting, skewness, and kurtosis are also 

 similar between studies. It appears that the physical sedimentary environment 

 at the sites sampled has not changed from 1976 to 1981. While the temperature 

 and salinity are different, they are well within the range of the natural 

 variation that open coast systems experience. 



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