2 2 



of community composition based on a sample area of 0.5 m vs 0.078 m 



yielded significant differences in estimated density for only 3 species. 



Overall, the percent contribution of each species was similar between 



the two sampling methods. A total of 36 taxa were found in the large 



core samples and not in the small corer; however, over half of these 



were represented by only 1 individual. 



Based primarily on species area curves presented in the 1978 study, 



it was recommended that our program should increase the total surface 



2 2 



area sampled from 0.078 m to at least 0.1 m . A reduction in sieve 



mesh size (0.7 mm to 0.5 mm) was also suggested but not evaluated. 



Program changes submitted and approved as Technical Specifications in 



April 1981 included increased surface area and decreased sieve mesh 



size. In addition, five subtidal and one inter tidal sampling station 



were deleted from the program; this permitting collection and analysis of 



15 replicates without increasing manpower requirements. 



2 

 Since March 1979, 15 replicates (0.117 m surface area) have been 



collected quarterly at the Millstone benthic sites and processed using a 

 0.5 mm mesh sieve. An evaluation of increased surface area sampled and 

 reduced sieve mesh was performed in 1981 since the sample comparison in 

 1978 did not compare the same sample volume (25 cm (i.d.) x 10 cm deep 

 for large cores vs 10 cm (i.d.) x 5 cm deep small cores). In addition, 

 the previous study used a 0.7 mm sieve rather than a 0.5 mm sieve. 

 Species area curves were generated for each month and station 

 sampled and the results are summarized as the percent of species found 

 in 10 of 15 replicates (Table 4). At all sites, over 90% of the total 

 species collected by 15 replicates were also collected by only 10 repli- 

 cates. On a seasonal basis, percentages obtained in June and December 

 were more consistent between years than those of March and September. 



7 



