(Figure 3-4) . The wide-spread distribution of reduced material 

 suggests recent local erosion on a much broader scale, an 

 apparent result of Hurricane Gloria. 



The frequency distributions of boundary roughness 

 values for the dredged material mound, edge and ambient stations, 

 and the CLIS-REF site were similar for all three areas, with the 

 major mode for small-scale topographic relief being 0.8 cm 

 (Figure 3-5) . Boundary roughness values have increased 

 significantly in all three areas since the June survey 

 (Mann-Whitney U-tests, p < 0.05; Figure 3-6). This represents 

 the first change in small-scale topographic relief at the site 

 since December 1984. Both seasonal changes in the rates of 

 biogenic reworking and physically-induced surface erosional and 

 depositional events can result in changes in boundary roughness. 

 The boundary roughness observed in this survey appeared to be 

 physically induced; again, it was apparently related to the 

 influence of Hurricane Gloria. Many images revealed erosional 

 features such as mud clasts and exposed worm tubes (Figure 3-7) . 



There were no remarkable spatial trends or patterns in 

 the distribution of mean apparent RPD depths at the FVP site in. 

 October (Figure 3-8). The average RPD depth was 2.39 cm at mound 

 stations, 1.95 cm at edge and ambient stations, and 2.04 cm at 

 CLIS reference; the frequency distributions of RPD values for 

 these three areas all have a major mode of 2 cm (Figure 3-9) . The 

 October RPD depths did not vary significantly among the mound, 

 edge and ambient and CLIS reference stations. However, at all 

 three areas RPD values showed a decrease from March to June and 

 from June to October 1985 (Figure 3-10) . 



The decrease in RPD depths at the mound stations 

 between June and October was not statistically significant; 

 however, the mound station values were significantly shallower in 

 June than in March (Mann-Whitney U-test, p < 0.05). Edge and 

 ambient RPD depths have significantly decreased since June 

 (Mann-Whitney U-tests, p < 0.05). Moreover, RPD depths at edge 

 and ambient stations have decreased progressively throughout the 

 past year (the March and June average RPD values equaled 4.33 and 

 2.90 cm, respectively). At CLIS-REF, RPD depths were also 

 significantly less than in June (Mann-Whitney U-test, p < 0.001). 



The atypically shallow RPD depths observed at both the 

 reference and grid stations during the October survey were 

 largely a result of the physical disturbance caused by Hurricane 

 Gloria. Several REMOTS® photos revealed oxygenated surface 

 sediment layers which appeared to be truncated (Figure 3-11) . 

 Scour by bottom currents probably resulted in erosion of surface 

 sediment layers over large areas of the Sound, especially in 

 shallower regions. Near-surface, biogenically reworked sediments 

 are susceptible to erosion due to their low shear strength, 

 increased porosity and high water content. In the center of the 



