knowledge, the short-term effects of waste disposal on different marine 

 ecosystems are discussed in the following sections. 



a. Effects of Ocean Dumping on Benthic Organisms . Some studies on 

 the effects of dumping or related activities in other coastal areas, have 

 not found extensive damage to the marine environment (U.S. Fish and 

 Wildlife Service, 1970; Kaiser Engineers Consortium, 1969; Allan Hancock 

 Foundation 1965; Brehmer, et al , 1967; Harrison, 1967). The results of 

 these studies are summarized in section II of this report. In all studies, 

 the most marked effects and changes have been observed in benthic com- 

 munities, because these are the most sensitive to environmental stresses 

 due to their specialized adaptations and limited mobility. 



Studies completed in the Bight dumping grounds have found impoverished 

 benthic populations. SHL found that both the benthic raeiofaunal and 

 macrofaunal organisms have been affected by the disposal of sewage and 

 dredge spoils in the Bight. The presence of these wastes have significant- 

 ly reduced the diversity of benthic communities, and this reduction in- 

 dicates environmental stress caused by dumping. 



In the absence of adequate spatial or temporal base-line information, 

 this conclusion is not fully supported. Even under natural conditions, 

 species diversity varies greatly with natural stresses. A lowered species 

 diversity index may not necessarily be a negative factor. Whether species 

 diversity or reduction in the abundance of certain species should be used 

 as the sole criterion of environmental stress, remains to be seen. 

 Species diversity nonetheless is useful as an index to be used in con- 

 junction with other indices of pollution. 



A study of the effects of dredging and spoil disposal in areas of San 

 Francisco and San Pablo Bays indicated a significant reduction of numbers 

 and species composition of benthic organisms and demersal fish. (U.S. 

 Fish and Wildlife Service, 1970). A quantitative correlation of species 

 diversity depression with waste water toxicity has been indicated by 

 previous studies (Kaiser Engineers Consortium, 1969; Allan Hancock 

 Foundation, 1965). These studies found a linear relationship may be an 

 oversimplification, since species diversity may result from physical 

 and chemical variables, some of which may have nothing to do with manmade 

 pollution. A study of Rappahannock Shoal spoil disposal area (Brehmer 

 et al, 1967) for example, indicated a greater species diversity and 

 number of organisms in the spoil areas than in the natural ooze-covered 

 substrate in the deeper parts of Chesapeake Bay. 



Wilhm and Dorris (1966, 1968); Wilhm (1967) and Gibson (1966), have 

 discussed the use of species diversity as. an indicator of stress due to 

 natural physical factors and pollution. The use of chemical properties 

 as indices of environmental stress may be misleading, since chemical 

 measurements indicate water quality at the time of sampling and not past 

 contamination or conditions prevailing over long periods. 



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