Statistical comparisons were also made between the 1986 

 data set and the results of chemical analyses of samples collected 

 from stations in the vicinity of the STNH-N disposal mound in 1982 

 and 1984 (Tables 3-25 and 3-26) . These tests did show some 

 apparent trends with time. For stations 400W, 400E and 100S, 

 several of the trace metals showed significantly higher 

 concentrations in 1982 compared to 1986. The Center station, 150W, 

 100N and 250S showed no change from 1982 to 1986, and stations 200E 

 and 200N showed significantly higher concentrations in 1986 

 compared to 1982 (Table 3-26) . Comparisons between the 1984 and 

 1986 results did not comfirm any of these patterns except in the 

 case of station 200E, where the 1986 concentrations were still 

 significantly higher than the 1984 levels for several trace metals. 



3.6 Benthic Community Analysis 



The visual descriptions of sediment samples collected 

 for benthic community analysis indicated various grain sizes 

 occurring at each disposal mound (Table 3-27) . Fine sand was found 

 at STNH-N and CS-2 as a result of the capping operations conducted 

 there. The oily silt-gravel mixture found at CLIS-86 was the 

 result of recent disposal operations. 



In the list of species found in each area sampled (Table 

 3-28) , family names were included only when they provided 

 information on included species. As an example, opisthobranch 

 gastropods in three families were listed together rather than in 

 three parts of the table. 



The sieve residues from the CLIS reference samples 

 contained the shells of Mulinia and Nucula, fine organic detritus, 

 and a small amount of yellow sand. FVP Center samples contained 

 gray sand with mica, coarse terrestrial plant debris, and shells 

 of estuarine species. Oil contaminated the FVP material. The MQR 

 samples contained a small volume of fine plant debris. The STNH-N 

 samples contained a large volume of sand and estuarine shells. 



The total number of species and individuals in major 

 taxonomic groups in each sample was recorded (located at the end 

 of Table 3-28) . The average number of individuals per sample and 

 the total number of species per station were: 100 and 20 for MQR 

 Center, 487 and 37 for FVP Center, 2053 and 35 for CLIS reference, 

 and 4268 and 42 for STNH-N Center. 



Although these four stations are at similar depths and 

 within a few miles of each other, there were large differences in 

 the grain size and contamination level of the sediment at each 

 station. Detailed knowledge of station histories would be 

 necessary to reach conclusions concerning the progress of faunal 

 recolonization and the relative sensitivity of community 

 components . 



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