disposal area, this scouring resulted in some images lacking or 

 exhibiting very shallow redox layers; highly reduced dredged 

 material that was formerly underlying aerated sediment was 

 evident at the sediment-water interface (Figure 3-12) . In 

 adjacent ambient regions, evidence of significant surface erosion 

 was indicated by the presence of methane. Methanogenesis occurs 

 at depth in the sedimentary column whenever pore-water sulphate 

 is exhausted. In central Long Island Sound, methane production 

 usually occurs below the REMOTS® prism penetration depth (15-20 

 cm; Needell et al . , 1987) ; methane has not been observed 

 previously at the FVP site. In this survey, station 1000E showed 

 a relatively shallow RPD and sedimentary methane pockets (Figure 

 3-13) . These features suggest that a notable amount (5-10 cm) of 

 surface sediments had recently been removed. 



While Hurricane Gloria represented a major physical 

 disturbance to the entire central Long Island Sound region prior 

 to the October survey, the trend of decreasing RPD depths 

 observed at FVP from March to June suggests that the disposal 

 site had been subject to disturbance factors in the months 

 preceding the storm. The relatively shallow RPD depths exhibited 

 in June at both mound as well as edge and ambient stations were 

 attributed at the time to localized erosion and redistribution of 

 the dredged material mound. It is also possible that this area 

 was beginning to experience adverse effects related to the 

 development of near-bottom hypoxia. At CLIS-REF, the extensive 

 DAMOS sampling which occurred over the two years prior to the 

 October survey represents another disturbance factor which must 

 be considered. Past sampling at this station by U.S. EPA 

 personnel from the Narragansett Environmental Research Laboratory 

 (ERLN) involved the removal of relatively large volumes of 

 sediment for chemical analyses and for collection of organisms 

 for body burden analyses. The use of precision navigation for 

 deployment of the various sampling devices means that a 

 relatively small area of the bottom was subjected to intense 

 disturbance at regular intervals. Because of this, it is 

 difficult to determine uneguivocally how much of the disturbance 

 seen at the reference station in October was attributable solely 

 to the effects of the hurricane and how much was attributable to 

 the long-term disturbance from the FVP and DAMOS sampling 

 efforts. The current DAMOS sampling procedure of using more than 

 one reference area should alleviate this potential source of 

 ambiguity when interpreting results from future surveys. 



Twenty-eight percent of the mound station replicates 

 exhibited Stage III assemblages; this compares with 35% of the 

 edge and ambient replicates and 3 0% of the CLIS-REF replicates 

 (Figure 3-14) . The mound region exhibited relatively low 

 abundances of Stage III seres throughout 1985, the highest level 

 being 43% in March. Of edge and ambient replicates, 77% revealed 

 Stage III infauna in March. This relative abundance decreased 

 dramatically to 31% in June, and it remained at this low level in 



