in the area, and would enhance marine productivity. 



In their investigation of the Firth of Clyde Estuary dumping grounds, 

 MacKay, Halcrow and Thornton (1972) report an increase in the productivity 

 of that particular area which was attributed to nutrients in the waste. 

 Similarly, Yentsch (Ketchum, 1969) plotted the log of inorganic phosphorus 

 against the log of chlorophyll-a, and determined a linear correlation 

 between the two. SHL, utilizing Yentsch's technique and its own data for 

 the Bight, did not find a linear correlation. Other environmental factors 

 therefore must affect the relationship between chlorophyl productivity and 

 the phosphorus content in the waters in the disposal areas of the Bight. 

 One factor, perhaps the most important for the area, is salinity. Tur- 

 bidity may be another. 



SHL reported that the bulk of primary productivity occurred in waters 

 of river origin with lower salinity. SHL also stated that nutrification 

 of the watei of the dumping grounds did not result in an extensive in- 

 crease in the primary productivity of the area. Barber and Krieger (1970) , 

 suggested that phytoplankton cell division is retarded in water samples 

 obtained from the sewage sludge grounds. They have given no reason for 

 the suggested retardation, and have not related it to nutrient concentra- 

 tions. 



h. Heavy Metals . Heavy metals which are often present in the sea 

 and are toxic to man in varying degrees, include, mercury, silver, arsenic, 

 chromium, cadmium, copper, lead, nickel, and zinc. The toxic effects of 

 these metals may be persistent and cumulative over the long term. Minute 

 quantities of certain heavy metals are known to be important in metabolic 

 processes of man. Most heavy metals serve no known biological function 

 in the marine environment, and can act synergistically with other chemical 

 substances to increase toxicity. 



Marine animals, especially shellfish, are known to concentrate these 

 heavy metals in their tissues, and (if eaten) may be a toxic source to 

 man. Because of their toxicity and cumulative toxic effect, large con- 

 centrations of heavy metals constitute perhaps the most dangerous chem- 

 ical species in the marine environment. 



Heavy-metal criteria and limits for water vary widely from State to 

 State. Neither New York nor New Jersey have defined specific criteria. 

 The NTAC of EPA in its report "Water Quality Criteria," cites the U.S. 

 Public Health Service Drinking Water Standards (EPA, 1972) . According 

 to these standards, desirable criteria for water place heavy-metals con- 

 centrations near zero. These are for drinking water, and are completely 

 unrealistic for coastal marine environments such as the New York Bight. 



Heavy metals are associated with ocean dumping in other areas. A 

 study of the sewage sludge dumping in the Thames River Estuary, in England, 

 found high concentrations of heavy metals in the sediments. (Shelton, 1971) 

 High values of heavy metals have been reported for the Firth of Clyde, 

 Scotland (Makay, Halcrow and Thornton, 1972), and for the coastal waters 

 of California (Hlavka, 1971). 



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