IV-403 

 SECTION 3. EXTENT OF POLLUTION EFFECTS 



Environmental damage from human activities manifests itself 1n changes 

 in water quality and in changes in living communities. Either or 

 both may be caused by any of the kinds of pollution or sources of 

 pollution already discussed. 



This section contains separate discussions of degradation of water 

 quality and damage to living communities, but water quality is an 

 integral part of estuarine ecosystems and changes in one are usually 

 reflected in the other. An accurate and thorough analysis of the 

 relationship of pollution to environmental damage must recognize 

 these related factors. The compartmentation of discussion in this 

 section is necessary because water quality studies and ecological 

 studies are rarely conducted simultaneously in the same system. This 

 situation, indeed, is one major existing deficiency in the present 

 approach toward study of the estuarine environment. 



DEGRADATION OF WATER QUALITY 



One key to the degree of environmental impact is measurement of 

 alteration in water quality. Extensive data have been collected on 

 a few of the estuaries with the most severe problems, and limited 

 information 1s available on other estuarine systems to outline the 

 emergence, or document the existence, of water quality problems. 

 For the majority of the Nation's estuarine systems, however, there 

 are little or no data to describe existing water quality conditions. 



