15. The frequency distributions of surface boundary 

 roughness values for the sample grid and WLIS-REF are shown in 

 Figure 3-7. Boundary roughness is the vertical range of small- 

 scale topographic relief observed in the REMOTS images. The 

 major mode for the area surveyed is at 0.4 cm, suggesting that 

 the region is generally a low-kinetic one. However, the presence 

 of mud clasts at five stations (excluding the southernmost 

 transect) indicates that some localized bottom disturbance has 

 occurred (Figures 3-4 and 3-6) . This disturbance is likely both 

 physically-induced disposal operations and biogenic macrofaunal 

 foraging. Near-surface patches of highly reduced sediment are 

 evident in 36% of the WLIS REMOTS images (Figure 3-8) . Reduced 

 sediment patches have also been observed at the Central Long 

 Island Sound Disposal Site (CLIS) surveyed in the summer of 1985. 

 This phenomena may be related to the large-scale sediment 

 reworking activity of deep-dwelling Stage III infauna and/or 

 large, mobile predatory epifauna, e.g. decapods and stomatopods. 

 The ecological significance of this phenomena and its impact on 

 dredged material disposal mounds is discussed in detail in the 

 CLIS August and post-storm report. 



16. The frequency distribution of the Redox Potential 

 Discontinuity (RPD) depths for the survey area and WLIS-REF is 

 shown in Figure 3-9, and the spatial distribution of RPD depths 

 is given in Figure 3-10. The RPD value is a measure of the 

 apparent depth of aerobic sediment, indicative of bioturbation 

 activity. In general, the WLIS disposal site has historically 

 displayed relatively shallow RPD values. The average RPD depth 

 for the entire site is 2.95 cm; this is not significantly 

 different from the average RPD depth of 3.24 cm at WLIS-REF 

 (Mann-Whitney U-test, p = .4107). In general, this region of 

 Long Island Sound is "stressed" due to high natural and 

 anthropogenic inputs of organic-rich material coupled with 

 restricted water movement. These conditions result in high 

 sediment BOD and COD. Organic-loading is further indicated by 

 the high contrast RPD's prevalent throughout the region, i.e. 

 sediments at depth are apparently highly reduced (manifested as 

 very low reflectance) . Several stations also exhibit rebounded 

 RPD's (Figures 3-10 and 3-11); this is likely related to the 

 seasonal temperature increase and the associated increase in 

 sediment oxygen demand. Figure 3-10 shows that there is no 

 obvious spatial pattern in the distribution of RPD depths across 

 the survey area. 



17. A map of infaunal successional stages is shown in 

 Figure 3-12. Based on the theory that organism-sediment 

 interactions follows a predictable sequence after a major 

 seafloor perturbation, the successional stage represents the 

 functional group of infauna present in REMOTS images. Sixty- 

 seven percent of the images show Stage I seres, reflecting the 

 disturbed condition of the region. Of 11 stations exhibiting 

 Stage III seres, eight are located in the western half of the 

 survey grid. This may be related to the fact that the dredged 

 material disposal mounds are located in the eastern portion of 



