I 



Butcher (1955) states that in the presence of numerous and complex 

 pollutants, environmental stress can be determined best from prevailing 

 biological conditions rather than from chemical measurements.^ To a 

 degree this is a correct approach, but maybe not the most reliable. 

 Observation and analysis of species diversity of benthic populations, if 

 supported by sufficient base-line data, can undoubtedly help to assess 

 environmental severity. Such base-line data does not exist for the 

 N.Y. Bight. Use of chemical indices as a sole determining factor for 

 water quality may not be sufficient or definitive, biological factors 

 also should be considered. Biological methodology should focus on 

 selected "key" species of fishes or invertebrates that could indicate 

 environmental stress, rather than attempt to sample one entire group 

 excluding all others. 



Disposal of wastes in the Bight presents a stress to the benthic 

 communities of the area, but without base-line information, factors 

 injuring benthic organisms are not completely understood. Reduction of 

 species diversity may be the result of synergistic chemical -physical 

 effects; some of these may be associated with dumping. No separation of 

 individual stress factors, can be made because of the limited data. 

 Furthermore, the N.Y. Bight dumping grounds have certain estuarine 

 characteristics, and do not represent an open marine environment. 

 Located at the mouth of a major estuary, this area experiences large 

 variations of temperature, salinity and of other chemical -physical 

 variables. 



Reducing sediments cause a reduction of the dissolved oxygen near 

 the sediment-water interface. Reduction of oxygen and physical burial 

 by continuous dumping, probably cause the most immediate adverse effect 

 on benthic communities. Oxygen reduction, although an important factor, 

 occurs only for brief periods in the summer, and it appears to be a 

 widespread phenomenon in the Bight. 



Burial of benthic organisms depends on the quantity of waste, on 

 the rate of disposal, on the settling rate of the waste, and on the 

 areal extent -of dumping and settling. A study of a dredge spoil dis- 

 posal site in Rhode Island Sound (Saila, et al , 1971) concluded that 

 most mollusk species could reach the sediment surface after shallow 

 burial; less mobile forms were buried; fish and lobsters could withstand 

 high concentrations of suspended sediment for short periods, and lobster- 

 ing on the perimeter of the dump was good; quahogs were killed by burial 

 near the dump center, but not on the perimeter; and amphipods were found 

 throughout in great densities. Similarly in a study of a shallow-water 

 dredge spoil disposal site in upper Chesapeake Bay, Cronin et al (1967, 

 1970) observed no significant losses of benthic organisms as a result of 

 burial. Certain species began repopulation soon after deposition, and 

 1.5 years later were back to previous levels. 



In a study of a disposal site in the lower Chesapeake Bay, Harrison 

 (1967) concluded that disposal of spoil had only a transitory effect on 

 benthic populations. It should be pointed out that the quantity of 



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