water. Sediments which descend through over 9 meters of water 

 to the bottom spread out evenly and are quickly reworked into 

 older deposits. Much of the microtopography over both the 

 disposal area and ambient bottom is related to biogenic activity. 

 The highest boundary roughness is located at Station 100N, 

 related to the presence of the cohesive clay clasts (Figure 3-4) 

 at the surface. However, because of the deep penetration of the 

 camera into this material, the maximum extent of this boundary 

 roughness could not be determined at this particular location. 



The mean apparent RPD depth at the FADS Reference 

 Station is 4.77 cm; this is not significantly different from the 

 value measured in January 1986 (4.81 cm). At the disposal 

 location, RPD depths have not changed significantly since January 

 1986 (Figure 3-10) . In the present survey, the RPD values 

 measured at the disposal location are significantly less than 

 those at the reference station (Figure 3-11; p < 0.001, 

 Kruskal-Wallis test) . The shallowest RPD values are found at 

 stations which are located within the dredged material area 

 (Figure 3-10) . Mean RPD depths are particularly shallow (< 2 cm) 

 at Station CTR, 200S, 300S, 100W, 300E, 400E, 300N, 400N, 600N 

 and 2 50NE. The shallowest RPD depths are located at Station 

 3 00S, which exhibits highly reducing sediment at the sediment- 

 water interface (Figure 3-8) . The lack of an apparent RPD at 

 300S indicates that significant infaunal colonization of the 

 dredged material at this station has not occurred. 



The distribution of infaunal successional stages shows 

 that most stations located on disposed dredged material have been 

 successfully colonized by subsurface deposit-feeders (Stage III 

 seres; Figure 3-12) . However, two stations were apparently 

 devoid of macroinf auna : Station 100N, consisting of 

 overconsolidated cohesive clay-like material and Station 300S, 

 which exhibited reducing sediments up to the sediment-water 

 interface. Most of the other stations surveyed which are located 

 on dredged material are dominated by Stage III seres and are 

 similar in their successional status to the FADS Reference 

 Station. 



The Organism-Sediment Index (OSI) values from stations 

 in the "DGD" disposal area (Figure 3-13) are significantly lower 

 than those measured at the FADS Reference Station (Figure 3-14; p 

 < 0.001, Kruskall-Wallis test). Within the disposal area, OSI 

 values have not significantly changed since the January 1986 

 survey . 



3 . 3 Sediment Characterization 



Results from the chemical analysis of the sediment 

 samples are presented in Table 3-1. These data are for the ten 

 sediment cores collected from ten of the fifteen grabs. The 

 results for several of the parameters indicate that the 



