These results suggest that the "retrograde" successional status of the 

 FVP mound has been reversed, which is consistent with the observed 

 deepening of the RPD depths. The successional status of the new CLIS 

 reference station is comparable to that found in surveys prior to 

 1985, when over 80% of the station replicates consistently showed 

 Stage III seres to be present. 



The mapped distribution of REMOTS* Organism-Sediment Index 

 (OSI) values showed no significant difference in OSI values among 

 mound, edge and ambient, and new CLIS reference stations (Figure 3- 

 25) . The frequency distributions of OSI values (Figure 3-26) at the 

 mound and edge and ambient stations both were left skewed, with major 

 modes at +11 and minor modes at +7. Likewise, the distribution of OSI 

 values at the new CLIS reference station was left skewed with a major 

 mode at +10. The Organism-Sediment Index values have increased 

 significantly since the October 1985 survey (p < 0.001, Mann-Whitney 

 U-test) , when the area exhibited a broad range of OSI values 

 indicative of extreme patchiness in benthic conditions. The increase 

 in OSI values obviously reflects the deepening of the RPD and the 

 increase in the number of Stage III seres since October 1985. There 

 appears to have been a convergence in the OSI values at the FVP mound 

 and the new CLIS reference station. 



3.3.2 Stamford-New Haven North (STNH-N) Mound 



The STNH-N disposal mound was capped with a layer of sand 

 from New Haven Harbor in June 1979. Bathymetric surveys performed 

 immediately following capping showed that the sand cap had a maximum 

 thickness of 3.5 meters at the mound apex (SAIC, 1980) . Cap thickness 

 varied in different places on the mound, but most of the sand appeared 

 to be concentrated within a 100 to 150 meter radius to the north, west 

 and south of the mound apex. Sand cap layers on the order of 1 meter 

 thick extended as far as 200 meters east of the mound apex. Beyond 

 the 100 to 200 meter radius, cap thickness decreased considerably and 

 was probably less than 20 centimeters in most surrounding areas. 



In the August 1985 survey, 37 of 43 REMOTS® photographs 

 showed a major modal grain-size of > 4 phi (silt-clay) , with the 

 exception of station Center and 200 S which showed very fine sand and 

 station 200 E, which showed a mud/sand/mud stratigraphy in the upper 

 20 cm of the sediment. Those stations away from the mound which did 

 not show the original surface sand cap were interpreted to represent 

 biogenically mixed sediments. Bioturbation apparently had mixed the 

 relatively thin (i.e., less than 20 cm thick) surface sandy sediment 

 with both underlying mud and newly settled mud from the water column 

 derived from ambient resuspension. The post-hurricane survey in 

 November 1985 showed evidence of surface scour and erosion at most 

 stations (Figure 3-27) , and post-storm boundary roughness was 

 significantly increased relative to the pre-storm (August 1985) survey 

 (SAIC, 1989a) . 



13 



