2.0 METHODS 



2.1 REMOTS® Sediment-Profile and Plan View Photography 



The August 1994 REMOTS® sediment-profiling survey was conducted along six 

 transects labeled CI through C6. Transects CI, C3, C4, and C5 surrounded the DG buoy, 

 and transect C2 was south of the buoy in an area of dense dredged material targets. This 

 allowed us to maximize the potential of encountering dredged material (Figures 1-2 and 2- 

 1) and to focus on depositional areas determined suitable for future disposal (Normandeau 

 Associates 1994). Transect C6 was situated in an area where side-scan records did not 

 contain any targets interpreted as dredged material in order to assess benthic recolonization 

 on ambient sediments located within BLDS. Two of the transects, CI and C6, were 

 oriented north to south while the remainder were oriented east to west. Each transect was 

 500 m long and consisted of ten stations spaced 50 m apart (a total of 60 stations; Table 2- 

 1). Two replicate photographs were taken at each station. 



Surficial sediments were photographed with a Photosea submersible plan view 

 camera to permit evaluation of surface features including benthic animals and 

 sedimentological features. The plan view camera was attached to the REMOTS® camera 

 frame and photographed the sediment surface prior to camera frame touch-down in order 

 to record an image of undisturbed sediments. 



2.2 Sediment Grab Sampling 



Sediment samples were collected with 0.1 m van Veen grab sampler at three of the 

 six transects (C2, C3, and C4) and at the reference area FG-23. Grab samples were 

 collected at Stations 1, 5, and 10 (Table 2-1) of each transect for a total of nine grabs. 

 Three replicate samples were collected at the reference area. 



Once the grab was brought aboard, four to five subcores were collected for 

 chemical analysis, and the remaining sediment was saved for benthic community analysis. 

 The chemistry subsample was composited in a teflon container and subsampled again for 

 polycyclic aromatic hydrocarbons (PAHs), metals, and grain size/total organic carbon 

 (TOC) analysis. The PAHs and metal subsamples were each placed in pre-cleaned 110 ml 

 I-CHEM jars, and the grain size/TOC subsamples were stored in ziplock plastic bags. 



The remaining sediment set aside for benthic community analysis was sieved 

 through a 500 micron screen. The residue was placed in one liter nalgene jars with both 

 internal and external labels. Each biological sample was fixed in 10% formalin and stained 

 with rose bengal, an organic stain. Following field collection, all sediment samples, 



Monitoring Cruise at the Historic Boston Lightship Disposal Site, August 1994 



