_/£ 



years. The REMOTS® hardware consists of a Benthos Model 3731 Sediment-Profile 

 Camera designed to obtain undisturbed, vertical cross-section photographs (in situ profiles) 

 of the upper 15 to 20 cm of the seafloor (Figure 2-2). Computer-aided analysis of each 

 REMOTS® image yields a suite of standard measured parameters, including sediment grain 

 size major mode, camera prism penetration depth (an indirect measure of sediment bearing 

 capacity/density), small-scale surface boundary roughness, depth of the apparent redox 

 potential discontinuity (RPD, a measure of sediment aeration), infaunal successional stage, 

 and Organism-Sediment Index (a summary parameter reflecting overall benthic habitat 

 quality). The REMOTS® determination of sediment grain size major mode is expressed in 

 phi imits; Table 2-2 is provided to facilitate conversions between these units and other 

 commonly employed grain size scales. REMOTS® image acquisition and analysis methods 

 are described fiilly in Rhoads and Germano (1982; 1986) and in the recent DAMOS 

 Contribution 128 (SAIC 2001a) and therefore not repeated herein. 



A series of REMOTS® sampling grids were estabhshed over NLDS in August 2000 to 

 obtain information related to the physical and biological composition of the benthos over the 

 three project mounds. The sampling grid established over the NL-91 and D/S Mound 

 Complex consisted of 1 3 stations in a cross-shaped pattern, replicating the surveys performed 

 in 1995, 1997, and 1998. The survey was centered at 41° 16.168' N, 072° 04.439' W, with 

 one station at the center (station CTR), three stations extending to the north of center (lOON, 

 200N, 300N), five stations to the east (lOOE through 500E), two stations to the south (lOOS 

 and 200S), and two stations to the west (lOOW and 200W; Figure 2-1; Table 2-1). Along 

 with evaluating benthic habitat conditions over the mound complex, the sediment-profile 

 photographs were used to map the distribution and thickness of new dredged material layers. 



The REMOTS® survey performed over the Seawolf Mound in August 2000 was part 

 of a long-term monitoring effort to examine benthic recolonization following the completion 

 of the capping operation in 1996. The station grid employed during both the 1997 and 1998 

 survey efforts was reoccupied in August 2000 to facilitate time-series comparisons among 

 data sets. The grid consisted of an eight arm radial pattem of 29 stations, spaced 75 m, 

 150 m, and 300 m from the center, as well as stations 450 m fi-om the center at the NE, N, 

 NW and WSW arms, and one station at the center (41°16.456'N, 72°04.863'W; Figure 2-1; 

 Table 2-1). 



The USCGA mound was also sampled as part of a long-term monitoring initiative to 

 verify that this disposal mound had fiilly recovered five years post disposal. A modified 1 3- 

 station cross-grid, established over the USCGA mound in September 1995 and centered at 

 41° 16.474' N, 072° 04.268' W, was re-occupied. Two stations were occupied along each of 

 the westem, northem, and southeastern arms of the survey grid, with three stations sampled 

 along the eastern and southem arms (Figure 2-1; Table 2-1). 



Monitoring Cruise at the New London Disposal Site, August 2000 



