At several stations with coarser-grained sediments, mean apparent 

 RPD depths exceeded the depth of the prism penetration. 



The infaunal successional stage was indeterminate at a 

 cluster of stations located on the center of the historic disposal 

 mound (Figure 3-15) . At these stations, relatively coarse 

 sediments or cobbles prevented the prism from penetrating deep 

 enough to adequately detect any deposit-feeding organisms which 

 might have been present at depth. Other stations on the actual 

 disposal mound were characterized by Stage I or Stage II 

 successional seres. At these stations, extensive recolonization by 

 the local mud-dwelling Stage III organisms may have been prevented 

 by the presence of relatively mobile sands (in response to the 

 higher energy regime) or otherwise coarse-grained disposed sediment 

 at the surface. 



Evidence of the indigenous Stage II and Stage III 

 assemblages was widespread at all other grid stations and at the 

 reference stations. A remarkable number of images showed large and 

 extensive sub-surface burrows (Figure 3-16) , which were most likely 

 due to the burrowing activities of lobsters (given the density of 

 lobster traps in the area at the time of the survey) and the 

 thalassinid shrimp Axius . In addition to the burrows, many images 

 had tubes of deposit-feeding polychaetes visible at the sediment 

 surface (Figure 3-17) , as well as feeding voids as evidence of 

 head-down, deposit-feeding Stage III taxa at depth (Figure 3-18) . 

 Ampeliscid amphipods, classified as Stage II organisms, occurred in 

 conjunction with the Stage III taxa at stations throughout the site 

 (Figure 3-19) . Some REMOTS® images showed only a few amphipod 

 tubes at the sediment surface (Figure 3-17) ; the amphipods also 

 occurred in dense assemblages or "mats" of tubes (Figures 3-11 and 

 3-20) . As a result, the majority of off-mound grid stations, as 

 well as the reference stations, had a Stage II on III successional 

 designation (Figure 3-15) . Overall, the REMOTS® photographs 

 revealed an extremely high density and diversity of organisms in 

 this area. 



The REMOTS® Organism-Sediment Index could not be 

 calculated at a cluster of grid stations at the center of the 

 historic disposal mound (Figure 3-21) . This was because either the 

 successional stage was indeterminate or the prism penetration was 

 inadequate at these stations. An OSI value of 11 was calculated 

 for most of the other grid stations and for the reference stations. 

 This was reflected in the frequency distributions of OSI values for 

 these two sets of stations, which have shown that the lowest OSI 

 value for any station was 9 (Figure 3-22) . These OSI values 

 indicate a benthic habitat of the highest quality and reflect the 

 general site characteristics of a deeply depressed RPD and a 

 persistent, stable infaunal assemblage representing an 

 "equilibrium" condition. 



