With the exception of Rhynchocoela and Oligochaeta, most 

 organisms were identified to species. Very small or damaged 

 individuals were assumed to be the same species as identified 

 individuals and were not recorded as unknown species. 



Individuals from each sample were combined and preserved 

 in 70% alcohol and a reference collection made (retained at URI) . 

 Sieve residue volume and composition were recorded, and residue 

 aliquots were preserved and archived. 



3 . RESULTS 



3.1 Brenton Reef Historic Disposal Site 



3.1.1 Bathymetry 



Depths in the area surveyed at the Brenton Reef site 

 ranged between 25.5 and 32.5 meters (Figure 3-1). The historic 

 disposal mound occurred as a well-defined feature centered just 

 inside the western disposal site boundary. This broad, circular 

 mound had a diameter of roughly 1600 meters and a minimum depth of 

 25.5 meters at its apex. The mound flanks occupied much of the 

 western half of the disposal site and extended approximately 500 

 meters outside the western disposal site boundary before ambient 

 depths of approximately 31-32 meters were encountered. The 

 southwest flank of the mound exhibited a much steeper slope than 

 the northern and eastern flanks. 



Even though the August 1978 bathymetric chart at Brenton 

 Reef (Figure 3-2) did not include the flanks of the mound west of 

 the disposal site boundary, comparison with the 1987 chart (Figure 

 3-1) indicates very little physical change over the major portion 

 of the mound. As in 1987, the mound in 1978 occurred as a broad, 

 circular feature covering the western half of the disposal site, 

 with a minimum depth of 25.5 m at the peak. In the earlier survey, 

 the southeast slope of the mound was also much steeper than the 

 slope to the north. At the time this was attributed to spillage 

 and short dumping from scows. Overall, no significant changes in 

 bottom elevations and in the areal extent of the disposal mound 

 appear to have occurred in the 9 year period between the August 

 1978 and October 1987 bathymetric surveys. 



3.1.2 Seismic Stratigraphy 



The sub-bottom profile survey performed at the Brenton 

 Reef site did not reveal any distinct or notable sub-bottom 

 acoustic features at or in the vicinity of the historic disposal 

 mound other than the disposal mound itself (Figure 3-3) . The mound 

 was easily distinguished as a surface feature distinct from the 

 original pre-disposal horizon; the sub-bottom data provided no 



