covered with coarser sands (Fig. 8). Sediment distribution and char- 

 acteristics in both the Inner and Outer Harbor are affected by the 

 nature of sediment from the Hudson River, the quantity and type of wastes 

 discharged within the harbor, tidal circulation, and frequency of dredging. 



Near the Harbor entrance, the sediments are coarser, consisting typical- 

 ly of sand and gravel. Further offshore, sand is the principal sediment 

 with a few scattered patches of gravel (Fig. 8) . 



Near the dumping grounds the sediments are not typical of sediments 

 found elsewhere in the Bight. These sediments are usually mixed, since 

 they originate from different regions, and include medium or fine grained 

 sands, muds with high organic content, and sewage sludge at different 

 stages of degradation. The sediments of the dumping grounds can be 

 termed anthropogenic because their deposition is not the result of natural 

 processes. Certain physical properties of the sediments dredged and dis- 

 posed of in the dumping area are given in Table 4. 



There appears to be little natural sedimentation on the Continental 

 Shelf of Bight at the present time. Topographic features, cut by rivers 

 flowing across the Shelf when sea level was lower, have not been covered 

 by more recent sediment deposition. The rivers carry little suspended 

 sediment, and the large estuaries and lagoons along the coast appear to 

 effectively trap this sediment (Meade, 1969) . According to Gross (1970) , 

 there is little or no natural sediment deposition to dilute or bury ocean 

 disposed wastes in this region. Removal of the waste sediments from the 

 dumping grounds - at least the finer sediments - may be taking place as 

 a result of lateral movement due to bottom currents, storm waves, in- 

 ternal waves and turbidity currents. The extent of lateral movement of 

 the sediments of the dumping area is not satisfactorily documented. 

 Turbidity currents probably play an important role in the removal of 

 waste sediment. Because the dumping grounds are near the head of the 

 Hudson Channel, it is possible that the channel acts as a conduit moving 

 such sediments to deeper water in the form of density currents. The 

 WHOI study concluded that a possible reason the Los Angeles area did not 

 experience a degraded marine environment was because of canyons. So 

 the nearness of the Hudson Canyon to the disposal grounds may be bene- 

 ficial provided that the ecological damage in the Canyon, resulting from 

 the presence of polluted sediments, is not too great. 



2. Water Motion and Circulation Characteristics 



The water motion and circulation characteristics of the Bight have 

 been studied in relation to dispersion patterns of waste materials dis- 

 posed of in the area. (Ketchum and Ford, 1948; Ketchum, et al, 1951; 

 Redfield and Walford, 1951; Beyer, 1955; Saila, 1968; Buelow, 1968; 

 Sandy Hook Laboratory, 1972) . Hydrographic studies of the Bight have 

 also been undertaken by Bowman and Weyl (1972) . 



No comprehensive synoptic hydrographic studies of the nearshore area 

 of the Bight have been made, and complete understanding of the surface 



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