the mound. The August 1983 report described the accumulation of 

 a thin surface mud layer at 5 stations located on the western side 

 of the central mound. This phenomena was interpreted as a 

 potential "lee-side" effect, i.e., a low kinetic area related to 

 the interaction of the flow field with the geometry of the disposal 

 mound. Fine-sand (3-2 phi) was found at the surface of station CTR 

 along with disarticulated bivalve shells (Figure 3-37) . This 

 suggested that the apex of the mound was being scoured by bottom 

 currents . 



The dredged material evident at CS-2 Station 600S 

 (equivalent to lOON, CS-1; Figures 3-35 and 3-38) represented 

 dredged material disposed between 1984 and 1985 at CS-1. The 

 capped mound locations which exhibited evidence of this recent 

 disposal activity were at the center of CS-1 and stations to the 

 immediate north. Near-surface, reduced sediment patches were 

 encountered at 76% of CS-1 stations (Figure 3-34) and 82% of the 

 CS-2 stations (Figures 3-35 and 3-39) . This widespread appearance 

 of previously buried dredged materials near the interface suggested 

 that the mounds had been disturbed. As discussed for the STNH-N 

 mound, this disturbance was probably biogenic. Feeding pockets 

 were evident directly beneath the reduced sediment patches (Figure 

 3-39) . 



The modal boundary roughness at CS-1 was 0.4 cm (Figure 

 3-40) , and CS-2 had a major mode shared between two class 

 intervals, 0.4 and 0.8 cm (Figure 3-41). These distributions were 

 unchanged from our September 1984 survey. CS-1 had an RPD depth 

 frequency distribution which was symmetrically distributed about 

 a major mode of 4.0 cm (Figure 3-40). There was no apparent 

 spatial trend in the apparent RPD depths (Figure 3-42) . Station 

 200NE had an anomalously shallow RPD value (1.93 cm) relative to 

 the rest of the mound. The distribution of RPD values at CS-2 had 

 a major mode at 5.0 cm (Figure 3-42). The spatial distribution of 

 apparent RPD depths at CS-2 (Figure 3-43) displayed a pattern 

 similar to CS-1. Pictures were not successfully obtained at 

 station 200NE. 



High order successional seres were found distributed over 

 both mounds (Figures 3-44 and 3-45) . Stations at CS-1 showed 

 predominantly Stage III-I seres; only three stations had all 

 replicates with Stage I or I-II seres (200N, 400S, and 400W) . 

 Similarly, only three stations at CS-2 showed all replicates in a 

 Stage I condition (400W, 400S, and 200E) . The abundance of Stage 

 III infauna had increased markedly at both capped mounds since the 

 September 1984 survey. 



The Organism-Sediment Index frequency distributions at 

 CS-1 and CS-2 revealed major modes at +7 and +11 respectively 

 (Figures 3-40 and 3-41) . CS-2 had 14 station replicates with an 

 index of +11 while CS-1 had only 9. There were no obvious spatial 

 trends in the distribution of OSI values (Figures 3-46 and 3-47) . 



14 



