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2.2.2 NLDS Reference Areas 



Data from three reference areas (NLON REF, NE REF, and WEST REF) were used 

 for comparison of ambient eastern Long Island Sound sediments relative to the material 

 deposited at NLDS through disposal operations (Figure 2-4). These three reference areas are 

 often sampled as part of sediment chemistry and benthic habitat surveys at NLDS. During 

 the 1997 and 1998 surveys, the NLDS reference areas were sampled as part of the sediment- 

 profile photography surveys over the Seawolf Mound. In addition, sediment cores were 

 obtained from randomly selected locations within WEST REF in 1997 and 1998 to serve as a 

 basis of comparison with sediment samples collected over the Seawolf Mound. 



A random sampling scheme was used each year to select stations within a 300 m 

 radius of the center of each reference area. A total of 13 stations were distributed between 

 the three reference areas. NLON REF (41°16.666' N, 72°01.971 ' W) and WEST REF 

 (41 °1 6.206' N, 72°05.971 ' W) were each sampled at four randomly selected stations. NE 

 REF (41°16.686'N, 72°03.371' W) was sampled at five randomly selected stations 

 (Table 2-4). 



2.3 Benthic Community Sampling 



2.3.1 Sediment Grab Sampling 



Sediment grab samples were collected at 6 of the 29 REMOTS® stations established 

 over the Seawolf Disposal Mound during the September 1 997 monitoring survey only 

 (Figure 2-5; Table 2-5). The grab samples were used to examine the benthic infauna 

 population and diversity, supplementing the benthic community assessment information 

 provided by the 1997 sediment-profile photographs. A 0.04 m 2 Young-modified Van Veen 

 grab sampler was used to obtain sediment samples from Stations CTR, 75E, 150N, 150W, 

 300SE, and 300WSW. One bottom grab was recovered from each station, and the sediments 

 were examined for color, texture, and redox potential discontinuity (RPD) depth. 



The sediment samples were then washed into a bucket and sieved through a 0.5 mm 

 screen. All material remaining on the screen (biota, shell, wood fragments, etc.) was 

 transferred to individual one liter plastic containers and fixed with a 10% buffered 

 formalin/seawater solution. The samples were left undisturbed for 48 hours, then re-sieved 

 with fresh water and transferred to a Rose Bengal stained, 70% methanol solution for long- 

 term preservation. The samples were then shipped to Cove Corporation of Lusby, Maryland 

 for species identification and enumeration (Blake and Williams 1997). 



Monitoring Cruise at the New London Disposal Site, Seawolf Mound 1995 - 1998 



