]J_ 



observed tidal data were later used to compare and verify the corrected NOAA data 

 generated from the Bridgeport Harbor station (Figure 2-2). 



A Seabird Instruments, Inc. SEACAT SBE 19-01 Conductivity, Temperature, and 

 Depth (CTD) probe was used to obtain sound velocity measurements at the start, midpoint, 

 and end of each survey day. The data collected by the CTD probe were bin-averaged to 1 

 meter depth intervals to account for any pycnoclines, rapid changes in density that create 

 distinct layers within the water column. A mean sound velocity was then calculated using 

 the bin-averaged values. 



The bathymetric data were analyzed using SAIC's Hydrographic Data Analysis 

 System (HDAS), version 1.03. Raw bathymetric data were imported into HDAS, 

 corrected for sound velocity, and standardized to mean lower low water using the NOAA 

 observed tides. The bathymetric data were then used to construct depth models of the 

 surveyed area. A detailed discussion of the bathymetric analysis technique is provided in 

 the DAMOS Navigation and Bathymetry Reference Report (Murray and Selvitelli 1996). 



2.4 REMOTS® Sediment-Profile Photography 



REMOTS® photography was used to detect the distribution of dredged material 

 layers, map benthic disturbance gradients, and monitor the benthic infaunal recolonization 

 and/or successional status of the G mound, H mound, and stations 200 and 300 m south of 

 the D mound center, as well as the WLIS reference areas. Cross-sectional photographs of 

 the top 20 cm of sediment were taken for analysis and intercomparison with the ambient 

 sediments of the adjacent WLIS reference areas (2000W, SOUTH, and SW-REF). 



Three replicate photographs were taken at 13 stations over the WLIS G and WLIS 

 H mounds (Figure 2-1). The REMOTS® sampling grids formed a cross-shaped pattern 

 with three stations along each of four arms and one station in the center. The REMOTS® 

 survey over the G mound was centered at 40°59.158' N, 73°29.020' W with station 

 spacing at 100 m. The H mound grid, centered at 40°59.228' N, 73°28.732' W, was 

 based on the same cross-shaped pattern, but sampled every 50 m (Figure 2-1; Appendix A, 

 Table 2-1). 



In addition. Stations D200S (40°59.146' N, 72°29.095' W) and D300S 

 (40°59.092' N, 72°29.095' W) were revisited during the 1996 field operations at WLIS. 

 These two stations were identified as areas of concern during the August 1993 REMOTS® 

 survey. Environmental conditions at D200S and D300S (shallower than expected Redox 

 Potential Discontinuity [RPD] depths and slow benthic recolonization) suggested that 

 continued monitoring of the southern flank of the D mound was required (Charles and 

 Tufts 1996). 



Monitoring Cruise at the Western Long Island Sound Disposal Site, July 1996 



