IV-358 



man. Examples of these situations are: (1) excessive drifting 

 plant growths that make bathing beaches unattractive, produce 

 unpleasant odors, foul the bottoms of boats, and spoil the esthetic 

 appearance, and (2) dense populations of rooted aquatics which 

 interfere with the movement and reproduction of fish (Figure IV. 5. 5). 



In any case it must be stressed that some other environmental condi- 

 tion, and not nutrients alone, may be the controlling factor 1n 

 such growths. The estuarine ecosystem is highly complex; its compo- 

 sition is dependent on a large number of variables, many of which are 

 as yet not understood. 



PATHOGENIC ORGANISMS 



One unfavorable consequence of municipal and some industrial wastes 

 is the contamination of the receiving environment with bacteria, 

 viruses, and other pathogens with public health significance. The 

 organisms, especially those from the intestines of warm blooded 

 animals, frequently persist for sufficient periods of time and dis- 

 tance to pose a threat to the health and well-being of unsuspecting 

 water users. Secondary channels of exposure to these organisms 

 exist through the contamination of shellfish which can be harvested 

 for food. 



Multiple use of any estuarine zone requires careful consideration of 

 the potential for contact with disease-producing agents. The 



