and late August to December, The concentrations of polychaete larvae in 

 the waters of the sewage sludge disposal grounds were similar as those 

 in other stations. 



Of the Cladocera, which are small crustaceans, three genera were found 

 in the Bight; Evadne sp. , Penilia sp. , and Podon sp. Evadne was the most 

 abundant of the three, present in densities of 50 to 7,000/m^ from middle 

 May until October. The other two genera were not as frequent, but during 

 July and August, they dominated the zooplankton population. Maximum 

 catches of Podon in the sewage sludge disposal area was 23,941/m^ in July 

 and for Penilia was 62,570/m in August. Because of their infrequency of 

 occurrence, however, Cladocera are not considered important constituents 

 of the total zooplankton fauna. Chaetognatha [arrow worms) one of the 

 most important constitutents of zooplankton because of their predatory 

 habits, were found in the SHL study area throughout the year. Arrow worms 

 were most abundant in the bottom waters and peak concentrations were found 

 from May to July. The highest number taken from a station a few miles 

 southeast of the dumping grounds, was 714/m^. There were no significant 

 differences in occurrence or abundance, between stations. 



The pelagic gastropod, Limnacia sp . , was present in the SHL study area 

 throughout the year. Its numbers per cubic meter ranged up to 1,780 in- 

 dividuals. The peak number occurred in October 1969, with peaks also in 

 August 1969 and February 1970. Salps, siphonophores and echinoderm larvae 

 were abundant from August to October. 



Other organisms, also taken sporadically in small numbers by SHL in- 

 cluded larvae of crabs, shrimp, phoronids, barnacles, bryozoans and fish 

 as well as mature forms of amphipods, mysids, pelagic polychaetes, tunicates 

 and hydromedusae. 



c. Micro-organisms . Although bacteria in wastes dumped in sea water 

 are rapidly killed, according to Greenberg (1956), certain enteric micro- 

 organisms survive in marine muds. It has also been reported by Buelow 

 (1968) that certain pathogenic micro-organisms survive sewage treatment, 

 and could conceivably infect and harm marine life. Still, other micro- 

 organisms have a beneficial effect because they induce a rapid and effici- 

 ent enzymatic breakdown of complex, and possibly toxic, hydrocarbons pre- 

 sent in the wastes. No studies have been made however, of micro-organisms 

 in the marine environment of the Bight, other than coliform bacteria. 



(1) Coliform Bacteria . The distribution of coliform bacteria is 

 a good indicator for delineating the impact areas associated with ocean 

 dumping of sewage and sewage sludge. Their presence, however, may be 

 temporary. Studies by the Food and Drug Administration (FDA) of the Dept. 

 of Health, Education and Welfare in the vicinity of the dumping grounds 

 indicate that shellfish in this area are bacterial ly contaminated (Buelow 

 et al, 1968). Samples of shellfish collected peripherally were found to 

 contain unacceptable levels of bacterial pollution. This contamination 

 was attributed to disposal of raw sewage and partially digested sludge 

 outside the prescribed locations, by violators "short dumping." Another 



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