56 



Irregularities or disturbances in the surface were quantified by determining the 

 boundary roughness for each replicate. With the majority of surface disturbance classified 

 as physical, replicate-averaged boundary roughness values ranged from 0.66 cm at 150W to 

 4.64 cm at CTR (Appendix A, Table 11). Replicate-averaged camera penetration depths 

 tended to be shallower than expected with ten of the thirteen stations displaying values less 

 than 12.0 cm. The mean camera penetration values over the MQR mound ranged from 7.19 

 cm at 150W to 18.67 cm at SOS. 



Dredged material was identified and measured at all 13 REMOTS® camera stations. 

 Replicate-averaged dredged material thickness ranged from 7.45 cm at 150W to near full 

 penetration (19.10 cm) at 508, with the thickness of dredged material consistently greater 

 than camera penetration (Appendix A, Table 11). Redox rebound intervals were not 

 detected in the subsurface sediments of MQR. No methane gas or indications of low DO 

 were noted in any REMOTS® replicate. 



The replicate-averaged RPD values for the 13 stations in the MQR project area 

 ranged from 0.55 cm at lOOS to 1.88 at 150N. The mean RPD value for the entire MQR 

 project area was 0.91 cm (Figure 3-25). Stage I organisms were present at all stations, 

 often accompanied by Stage II or Stage III organisms (Figure 3-26). Median OSI values for 

 the MQR project area ranged from 2.5 at CTR and lOON to 9.0 at 150N (Figure 3-25). 

 With the presence of stable benthic infaunal populations over the supplemental cap material 

 deposit, the OSI values appear to be primarily affected by the low to moderate RPD depths. 

 This indicates moderate to strong benthic recovery over the area of the MQR mound 

 affected by the recent deposition. 



3.2.4 Surface Sediment Chemistry and Grain Size 



Eleven sediment chemistry grabs were collected over the MQR mound and analyzed 

 for sediment grain size distribution, TOC, LMW PAHs, HMW PAHs, and metals content. 

 Comprehensive tables of the raw sediment chemistry data collected over the MQR mound 

 are located in Appendix C. Results normalized to TOC concentrations as well as fine- 

 grained material can be found in Appendix D. 



Results of the individual stations over MQR indicate that the mound is basically 

 comprised of two different sediment types. Sediments collected at the five stations located 

 on the eastern side of the mound (MQR-1, MQR-4, MQR-5, MQR-6, and MQR-7) were 

 comprised mainly of fine-grained sediments; of these, the major constituent was determined 

 to be silt (Figure 3-27). Silts and clays compose between 59.8% and 81.9% of the total 

 bulk sediment deposit on the eastern flank of MQR (Appendix C, Table 4). Six stations on 

 the western side of the mound (MQR-2, MQR-3, MQR-8, MQR-9, MQR-10, and MQR-1 1) 



Monitoring Cruise at the Central Long Island Sound Disposal Site, July 1994 



