13_ 



distinct layers within the water column. Sound velocity correction factors were 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 Bathymetry and Navigation 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 stams of the CLIS 95, CLIS 94, and NHAV 93 disposal mounds. 

 Cross-sectional photographs of the top 20 cm of sediment were taken for analysis and 

 intercomparison with data collected at the adjacent CLIS reference areas, as well as 

 previous surveys. 



The REMOTS® sampling grids over the disposal mounds formed a cross-shaped 

 pattern over the centers of the project mounds. Three replicate photographs were taken at 

 13 stations over CLIS 95 and five stations over the CLIS 94 and NHAV 93 disposal 

 mounds. The sampling pattern over the CLIS 95 mound consisted of three stations over 

 each of four arms and one station in the center. The pattern over the CLIS 94 and NHAV 

 93 mounds consisted of one station over each of four arms and one station in the center 

 (Figure 2-1). The REMOTS® survey over the new CLIS 95 mound was centered at the 

 CDA 95 buoy position (41°08.660' N, 72°53.042' W), with station spacing at 100 m 

 (Appendix A, Table 2-1). The CLIS 94 grid, centered at 41=09.343' N, 72°53.099' W, 

 was sampled every 100 m (Appendix A, Table 2-1). The REMOTS® survey over the 

 NHAV 93 mound was centered at 41°09.122' N, 72°53.453' W with station spacing at 

 200 m (Appendix A, Table 2-1). 



Data from tiiree reference areas (2500W, 4500E, and CLIS-REF) were used for 

 comparison of ambient central Long Island Sound sediments relative to the sediments 

 deposited at CLIS through disposal operations. Reference areas 2500W (41° 09. 254' N, 

 72°55.569' W) and 4500E (41°09.254' N, 72 50.565' W) were sampled at four randomly 

 selected stations. CLIS-REF (41°08.085' N, 72°50.109' W) was sampled at five 

 randomly selected stations (Figure 2-1; Appendix A, Table 2-1). 



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



