POLLUTION IN THE NEW YORK BIGHT: 

 A CASE HISTORY 



Joel S. O'Connor 



Office of Marine Pollution Assessment 



Northeast Office 



Old Biology Building, SUNY 



Stony Brook, New York 1 1794 



and 



Douglas A. Segar 



President, SEAMOcean 



P.O. Box 1627 



Wheaton, Maryland 20902 



DESCRIPTION OF THE BIGHT 



Physical Features 



Geographically, the New York Bight is a relatively sharp angle in the northeastern 

 U.S. continental shelf south of Long Island, New York, and east of New Jersey. The 

 shelf is about 180 km (112 mi) wide and has an areal extent of about 39,000 km : 

 (15,000 n mi : ). Depths over much of the Bight are between 30 to 60 m (98 to 197 ft), 

 and the shelf break is defined at a depth of 200 m (656 ft). The broad, gently sloping 

 shelf of the Bight is bisected by the Hudson Shelf Valley. 



The morphology of the Bight floor and the distribution of its surficial sediments 

 are controlled by sea-level fluctuations from continental glaciation over the past 

 several million years. At the time of the last major ice advance, the North American 

 ice sheet extended from Canada to Long Island and northern New Jersey. Sea level 

 was lowered to about 145 m (480 ft) below the present level about 1 5,000 years ago; 

 hence, the continental shelves became dry land. Since then, the ice has been melting 

 and the shoreline has retreated over the shelf to its present position. Many features 

 on the shelf today are the result of this fall and rise of sea level (Freeland and Swift, 

 1978). 



Extensive sampling of surficial sediments has provided rather detailed knowledge 

 of grain size distribution. The dominant material on the shelf floor is sand, to 10 m 

 (0 to 33 ft) thick, resting on Holocene clays. Unconsolidated fine sediments are regu- 

 larly resuspended and ultimately carried back into the estuaries or off the shelf edge. 

 Some persistent areas of muds or fine sediments occur in low areas, in the Christiaen- 

 sen Basin, Hudson Shelf Valley, and in smaller"mud patches" near Long Island. The 

 muds accumulate in relatively quiet, deep areas because these regions have less in- 

 tense wave and current energy. Nearshore mud patches develop because high con- 

 centrations of suspended sediments are available for deposition during calm periods 

 (Freeland and Swift, 1978). 



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