attributed by SHL to public inaccessibility to the area, reduced drifter 

 buoyancy, or other forms of drifter entrapment. On the basis of bottom 

 drifter returns (Figure 10) , SHL concluded that the bottom circulation 

 of this region of the Bight undergoes mild seasonal variation. 



3. Chemical Characteristics 



Physical-chemical studies of the Bight in the past (Ketchum, Redfield, 

 and Ayers, 1951; Redfield and Walford, 1951) have described the distribu- 

 tion of temperature, salinity, dissolved oxygen and iron in the area. 

 Iron content of sediments in and northeast of the dumping grounds has 

 been studied by Corwin and Ketchum (1956). Salinity, temperature, total 

 phosphorus, total iron and chlorophll-a data have been reported by 

 Ketchum, Yentsch and Corwin (1958) . 



Buelow, Pringle and Verber (1968), analyzed water extracts of sediment 

 samples taken near the sewage sludge dumping ground for copper, zinc, 

 chromium and lead. Limited trace metal analyses were also conducted on 

 black quahog Arctica islandica samples. Gross (1970) provided more in- 

 formation on the chemical nature of sediment in the Bight. The study 

 correlated high concentrations of metals with carbon-rich waste deposits. 

 A later investigation by Gross et al, (1971) measured the copper, lead, 

 silver and chromium content of surface deposits. 



SHL (1972) determined concentrations of phosphorus (ortho, organic, 

 meta and total), nitrate, total iron, dissolved oxygen, and chlorophyll-a 

 in water samples, and measured temperature, salinity, turbidity and pH. 

 Sediment samples were analyzed for heavy metals, petrochemicals, pesti- 

 cide metabolites and redox potential to correlate these characteristics 

 with the distribution of Lenthic organisms. Figure 20 shows the stations 

 occupied for chemical studies. Samples were collected on 27 cruises 

 from late January 1969 to mid- July 1970. Initially, stations on east- 

 west transects through the sewage sludge and acid disposal areas were 

 sampled bimonthly. These included Stations 69, 70, 71, 75, 76, 77, and 

 78. Stations located on transects to the north, south and between the 

 above stations were sampled monthly. This pattern included Stations 

 66, 67, 68, 72, 73, 74, 79, 80, and 81. 



Table 5 summarizes the ranges of values for certain chemical para- 

 meters measured in the Bight by the SHL. Fig. 21 shows the seasonal 

 variation of properties at two stations in the Bight determined by 

 Ketchum, et al, (1951). One station was near Scotland Lightship, the 

 other just southeast of the dumping grounds. 



a. Temperature and Salinity . Temperature and salinity data for the 

 waters of the New York Bight have been obtained by a number of investi- 

 gations studying physical -chemical properties (Ketchum, et al , 1951; SHL, 

 1972; Bowman and Weyl, 1972). Some of these data have been summarized 

 in the report by Home and his associates (1971) . 



The temperature and salinity of the Bight vary seasonally. Greater 



50 



