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The REMOTS® hardware consists of a wedge-shaped optical prism having a standard 

 35mm-camera mounted horizontally above in a watertight housing (Figure 2-2). The prism 

 resembles an inverted periscope, with a clear Plexiglas window measuring 15 cm wide and 

 20 cm high and an internal mirror mounted at a 45° angle to reflect the image in the window 

 up to the camera. Light is provided by an internal strobe that resides within the optical 

 prism. In order to equalize pressure and reduce refraction, the prism is filled with distilled 

 water. The prism sits inside a stainless steel external frame, and the entire assembly is 

 lowered to the seafloor using a standard winch mounted aboard the survey vessel. Upon 

 contact with the bottom, the prism descends slowly into the seafloor, cutting a vertical cross- 

 section profile of the upper 15 to 20 cm of sediment, and a photograph is taken of the 

 sediment in contact with the window. The resulting 35 -mm slides (images) showing 

 relatively undisturbed sediment profiles are then analyzed for a standard suite of measured 

 parameters (Rhoads and Germano 1982; 1986). 



Computer-aided analysis of each REMOTS® sediment profile image yields a series of 

 measurements. The standard measured parameters include 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), infaunal successional stage, and Organism-Sediment Index (a summary parameter 

 reflecting the overall benthic habitat quality). A detailed description of REMOTS® 

 photograph acquisition and interpretive rationale is given in DAMOS Contribution No. 60 

 (Parker and Revelas 1989), as well as in Rhoads and Germano (1982; 1986). The following 

 paragraphs provide brief descriptions of the interpretive framework and methods used for 

 the various measurement parameters. 



The sediment grain size major mode values are visually estimated from the 

 REMOTS® photographs by overlaying a grain size comparator that is at the same scale. For 

 REMOTS® analysis, sediment grain size major mode is expressed in phi units. This 

 measurement represents the dominant grain size in the entire frame (field of view) and may 

 not distinguish layers of coarser or finer material. A grain size scale for sediments has been 

 provided in Table 2-2, to allow easy conversion between phi units, millimeters, and standard 

 sieve sizes. 



The REMOTS sediment profile camera consists of an optical prism, which penetrates 

 the bottom under a static driving force imparted by its own weight. The penetration depth 

 into the bottom depends on the force exerted by the optical prism and the 



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



