The mean number of individuals per core and 95% confidence intervals 

 were plotted for each station and collection using 10 and 15 replicates 

 (Figs 1 and 2). Of the 54 densities plotted, only the March 1979 Intake 

 estimates (10 vs 15 replicates) were significantly different (p <0.05) 

 based on the overlap of the 95% confidence intervals. Although variances 

 associated with mean densities generally decreased by collecting 15 vs 

 10 replicates, the magnitude of the variance was still closely associated 

 to the size of the mean. Additionally, variance remained higher than 



the mean in all cases, whether 10 or 15 samples were collected. 



2 

 Mean infaunal densities/in and percent composition at each station 



and for each species were calculated from September 1979 to June 1980 



and results for the 10 dominant taxa are presented in Tables 5 and 6. 



The use of 15 replicates did not add nor delete any species from the 10 



dominants based on 10 replicates. Species rankings at each site were 



nearly identical for both replicate groups. Differences in a species 



ranking usually occurred between adjacent species, i.e., rank of Polycirrus 



eximius was 2nd with 15 replicates and 3rd with 10 replicates. The rank 



of Caulleriella spp. collected at the Giants Neck subtidal site changed 



more than any other taxon; this change involved a decrease in rank from 



8 (15 replicates) to 10 (10 replicates). 



Results of this 2 year study have shown that increased sample area 



2 2 



size (from 0.078/m per quarter to 0.117 m per quarter) has not signi- 

 ficantly changed estimates of infaunal density nor substantially altered 

 observed patterns of community composition. Collection of additional 

 replicates did not reduce the variance associated with species counts 

 and thus has not increased the statistical power of our infaunal monitoring 

 program. 



