seres. The MQR mound remained dominated by low-order successional 

 infauna. As discussed above, this persistent lack of Stage III 

 infauna at MQR is anomalous, and it may be related to high levels 

 of sediment contaminants. The OSI values at MQR in October (Figure 

 3-67) had decreased significantly since the August survey (Figure 

 3-63, Mann-Whitney U-test, p = 0.006). In August, the mound was 

 dominated by OSI values of +7. The decreased values observed in 

 this survey were entirely due to the decreased RPD depths; the 

 infaunal successional status of the mound had not changed. 

 Overall, of the CLIS disposal mounds surveyed subsequent to 

 Hurricane Gloria, the MQR mound showed the least evidence of 

 physical disturbance. 



3.3.5 Norwalk (NOR) 



Two previous REMOTS® surveys were conducted at the 

 Norwalk mound in January 1983, and September 1984. The 

 cross-shaped sampling grid consisted of nine stations. In August 

 1985, the sampling grid was extended in both the N-S and E-W 

 directions to produce an expanded view of the disposal mound. 



All stations had a major mode grain-size of >4 phi 

 (silt-clay range) as compared to a major mode of >4-3 phi 

 (silt-clay to very fine sand range) in the September 1984 survey. 

 This increase in the abundance of fine-grained sediments suggests 

 that a net deposition of fine-grained material had occurred since 

 the last survey. 



Reduced sediment patches were observed near the interface 

 at 53% of the Norwalk stations (Figure 3-68) . This material was 

 evident throughout the mound and most likely the result of 

 large-scale biogenic disturbance. 



The frequency distribution of small-scale boundary 

 roughness for the August survey (Figure 3-69) displayed a major 

 mode at the 0.4 cm class interval, compared to 0.8 cm in the 

 September survey. This implies small-scale "smoothing" of the 

 bottom had occurred due to currents, sedimentation, and 

 bioturbation . 



The shallowest mean RPD values at Norwalk (Figure 3-70) 

 occurred at stations 200E, 600E, 600S, and 600W. However, in 1984 

 the major mode for RPD depths was located at the 3 cm class 

 interval. In this survey the major mode for RPD depths was at the 

 5 cm depth class (Figure 3-69) , indicating increased bioturbational 

 activity at this mound. 



It is apparent that significant recolonization at CTR as 

 well as most of the stations north of center at Norwalk had 

 occurred since September 1984 (Figure 3-71) . In the 1984 survey, 

 one image from station CTR revealed an apparently azoic location 



18 



