material concentrations and a return to pre-storm conditions. The 

 slight increase in post-storm concentrations relative to pre-storm 

 levels indicated in the data plot was the result of instrumentation 

 bias introduced from deposition of some of the resuspended 

 materials on the windows of the optical sensor. 



Following the post-storm decay, concentrations remained 

 low for a period of approximately 3 hrs and then began a 

 progressive increase to a maximum approaching 30 mg/1 (Figure 

 3-92) . This increase was approximately coincident with the rebound 

 of the tidal velocity system; it appeared to be the result of 

 offshore advection of inshore materials suspended during storm 

 passage but retained within the nearshore shallow water areas due 

 to the absence of significant tidal flows. The timing of the 

 occurrence of peak concentrations and its coincidence with the 

 flood suggests that the source of these advected materials was to 

 the east of the deployment location and adjacent to Fishers Island 

 Sound. Timing also clearly eliminated streamf low-associated 

 suspended loads as a possible source of the materials moving past 

 the array. Sediment loads and discharge levels associated with the 

 streams entering the Sound to the east of the deployment point were 

 simply insufficient to produce significant far-field perturbations 

 within the local suspended material field. 



After the rebound in suspended sediment concentrations, 

 associated peak concentrations slowly returned to pre-storm levels. 

 The occasional spikes noted in the record during this period as 

 well as those observed on several occasions during the pre-storm 

 interval were most probably the result of the passage of suspended 

 organic detritus and were not considered to be evidence of 

 significant sediment transport activity. Their occurrence could 

 not be simply correlated with either the tidal current record or 

 concurrent temperature-salinity conditions. During the last half 

 of the record, the progressive removal, by ambient tidal flows, of 

 sediment deposited on the windows of the optical sensor most likely 

 resulted in the slow decline of the average apparent suspended 

 sediment concentration. The observed decay was not considered to 

 be evidence of gradual settling of storm-resuspended materials. 

 All indications are that the settling of these materials occurred 

 in a relatively short period of time essentially confined to the 

 immediate post-storm period. 



4.0 DISCUSSION 



4 . 1 August Monitoring Cruise at CLIS 



The bathymetric surveys conducted at CLIS during August 

 1985 did not reveal any significant changes (>20 cm) in the 

 topography of the disposal mounds there. The amount of dredged 

 material disposed since the 1984 survey was insufficient to 



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