On the basis of limited data, SHL concluded that the cell growth and 

 photosynthesis of phytoplankton collected near the bottom of the sewage 

 sludge dump was inhibited. This inhibition in primary productivity can 

 be attributed to reduction in light intensity due to turbulence induced 

 by the dumping rather than to toxic properties, and is considered 

 quantitatively insignificant. In surface waters, an enhancement of 

 primary productivity would be expected due to the nutrification caused 

 by the sewage sludge. Since no net reduction in zooplankton populations 

 was observed, ocean dumping in the area has had little effect on phyto- 

 plankton. 



e. Effects of Ocean Dumping on Bacterial Distribution . SHL con- 

 cluded that existence of coliform bacteria in the sediments and in the 

 waters of the New York Bight dumping grounds indicates the existence of 

 pathogenic bacteria. This conclusion was not confirmed by identification 

 of pathogens. Large populations of unidentified bacteria are found in 

 the surface waters of the dredge spoil disposal areas (Atlas 1972). 

 Mahoney (1972) relates the occurrence of coliform bacteria in the waters 

 near Sandy Hook with three genera of bacteria which have been associated 

 with pathogens resulting in fin-rot disease. The SHL study indicates 

 that the nutrient-rich waters of the dumping grounds could enhance the 

 presence of pathogens which could spread disease into uncontaminated and 

 ecologically important areas. The marine environment is foreign and 

 adverse to most bacteria found in sewage and sewage sludges. 



The rapid reduction in the number of coliforms after dumping, is 

 probably illustrative of a rapid bacteria die-off due to the disinfecting 

 capacity of sea water. Not only is the mortality of bacteria high, but 

 the rate of metabolism of the surviving bacteria is greatly reduced. 

 Mortality of bacteria would be even greater if the disposed wastes were 

 disassociated and dispersed. 



In his study at the Hyperion outfall in Southern California, Hlavka 

 (1971) suggested that survival of coliform bacteria associated with 

 floating particulate matter may differ significantly from that generally 

 expected. Based on this hypothesis and the observation of floating 

 particulates in the Bight dumping areas, SHL concluded that there may 

 be a significant accumulation of bacteria at the water-air interface 

 and in the water column as the particulates sink. Determinations of 

 percentage floatable materials in wastes and rates of bacterial survival 

 following dumping may be necessary to qualify this conclusion. Systematic 

 analyses of sediments and samples from the water column should be ob- 

 tained in the dumping grounds, the Hudson Canyon, and adjacent areas of 

 the Bight to determine positively the existence of pathogenic organisms 

 and the extent of bacterial contamination. Millipore filter techniques 

 should be used to concentrate bacteria that may escape count by standard 

 test techniques. 



f. Effects of Heavy Metals on Marine Organisms . Metals such as 

 cadmium, chromium, cobalt, tin, titanium, germanium and bismuth are 

 present in sea water in low concentrations, and are kno\m to be 



137 



