44 



can be structured" which might incorporate periodic sampling or remedial action (e.g., 

 capping; Germano et al. 1994). 



REMOTS® sampling at the reference areas was conducted to provide a comparison of 

 on-site versus ambient benthic habitats. The uniform sediment profiles from the 2000W 

 reference area indicated that these sediments represent ambient conditions. This is supported 

 by evidence of Stage III infaunal activity at all stations and a relatively deep mean RPD 

 comparable to the results of the 1990 survey (means of 3.8 cm and 3.9 cm, 1991 and 1990, 

 respectively). Interestingly, the mapped distributions of RPD depths at WLIS-REF/2000S 

 reference areas and at the disposal site were significantly shallower than those observed in 

 1990. The 1990 survey was conducted in July when water temperamres were higher than 

 during the 1991 survey. Water temperatures rise rapidly between June and July in Long 

 Island Sound and have an important effect on organism activity, rates of biomrbation, and the 

 depth of the apparent RPD. Had the 1991 survey been conducted in July, we would expect 

 to observe deeper RPDs in these areas. Nevertheless, areas determined to consist of ambient 

 sediments (Station E400N and the 2000W reference area) did not exhibit RPD depths 

 significantly shallower than those measured in 1990. 



Based on results from REMOTS® surveys in 1990 and 1991, the WLIS-REF area 

 appears to contain some relic dredged material. While these results show no evidence of 

 ecological degradation, clearly they are not consistent with the accepted definition of 

 "reference". The presence of dredged material in this area is likely the result of disposal 

 operations directed to the Eaton's Neck disposal area. Disposal within Eaton's Neck was 

 discontinued after 1972; therefore, the relic oxidized layers and sand/mud stratigraphy 

 observed in these REMOTS® photographs reflect the persistence of such features. This 

 persistence can serve to complicate the delineation of recently deposited dredged material 

 within the active disposal site. The level of infaunal recolonization at WLIS-REF, with 

 twelve of thirteen stations providing evidence of Stage in organisms, indicated that the 

 benthic habitat is relatively stable. 



Individual REMOTS® parameters observed at the 2000S reference area indicated that 

 this area has colonization attributes similar to the disposal site. With four of thirteen stations 

 exhibiting exclusively Stage I organisms and a median OSI of -f-4, this area is presimiably 

 subject to dismrbance gradients not experienced at the other reference areas. Wind-driven 

 current velocities in western Long Island Sound can increase rapidly as a result of storm 

 events and spring tides (SAIC 1988). Witii a relatively shallow water depth of 20 m, 2000S 

 is subject to erosional and depositional forces not experienced either within the WLIS 

 disposal site or at the other reference stations, 2000W and WLIS-REF. In addition to relic 

 RPD layers and sand/mud stratigraphy, the 2000S reference area exhibited a greater 

 percentage of coarser grain sizes than found at the WLIS-REF/2000W reference areas or the 

 disposal site. The sediment grain size analyses showed that sediments at 2000S consisted of 

 45% fine sand (4-2 phi) and 42% silt/clay (>4 phi) whereas reference areas 2000W and 



Monitoring Cruise at the Western Long Island Sound Disposal Site, June 1991 



