however, varied considerably eimong transects and sampling periods without any 

 pattern. The densities of chironomids generally averaged higher at stations 2 

 and 3 on transect III than elsewhere probably because of an accumulation of 

 silty clay there which provided a more suitable substrate for colonization by 

 chironomids. Generally the densities of chironomids in June and July were 

 higher than in October at nearly all stations in both years. 



Of the 38 other taxa represented in the samples, Ostracoda, Rh6±>docoela, 

 Nematoda, Caenis, Pontoporeia hoyi, Acarina, Corixidae, and Pisidium were found 

 frequently; collectively, they made up 5.7 percent of the total macrozoobenthos 

 (Table 4). 



Index values (CA) obtained by applying Morisita's test of community simi- 

 larity to the data (Table 7) indicate that the macrozoobenthos communities at 

 station 1 in transects I to VI in 1980 differed in 9 of 18 comparisons from the 

 communities present on these same stations in 1981. At stations 2 to 4, 

 however, the index values indicate that the macrozoobenthos communities in 1980 

 were either similar or very similar to those in 1981 in 51 of 54 comparisons. 



5. Fish . 



Almost 12,100 fish representing 31 species were caught in 36 gillnet sets 

 and 18 beach seine hauls during the study (Table 8; Apps. D and E). Gizzard 

 shad ( Dorosoma cepedianum ) were 5 2.7 percent of the combined total catch and 

 spottail shiners ( Notropis hudsonius ), alewives ( Alosa pseudoharengus ) , and 

 troutperch ( Pe r cops i s omi s comaycus ) were about 10 to 13 percent each of the 

 total; four species contributed about 1 to 7 percent each and the remaining 23 

 species made up less than 1 percent each. With the exception of the gizzard 

 shad which was taken in large numbers only in 1980, the species that dominated 

 the catch in 1980 were also the most abundant ones taken in 1981 . The list of 

 species caught in 1981 differed little from that for 1980; only a few of the 

 least abundant species were added to or lost frcan the list in 1981. 



More fish were caught in both types of gear in 1980 than in 1981 (Table 

 8). The smaller gillnet catch in 1981 resulted almost entirely from a decrease 

 in the catch at transects I and VI, the reference transects (Teible 9). The 

 smaller seine catch in 1981 was due to much lower catches in July and November 

 1981 than in the corresponding periods in 1980; these decreases in July and 

 November offset the increase over 1980 levels that occurred in the catch in 

 June 1981 on transects IV and VI. The low catch in July 1981 appears to have 

 resulted from a general reduction in the abundance of almost all species (App. 

 E), whereas the low catch in November 1981 reflects only a sharp reduction in 

 the abundance of gizzard shad (Table 10). 



IV. DISCUSSION 



1 . Beach Face Profile . 



Changes in the beach face profile that are evident in Figures 3, 4, and 5 

 reflect the Corps' beach nourishment activities in October 1980, which included 

 the removal of beach sediment from area A, the deposition of that sediment in 

 area B, and the deposition in area C of sediment from a leind borrow site; they 

 also reflect the littoral drift of beach sediment during the period of study. 



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