IV-8 



animals and plants which live in the bottom, on the bottom, in the 

 water, on the water, and in the marshes which border much of the 

 coast. The various communities in the estuarine zone are character- 

 ized by measuring the identity, distribution, and abundance of the 

 species present, ranging from bacteria and the minute phytoplankton 

 which are the primary users of solar energy to the fish, shellfish, 

 and other wildlife which are the final steps in the food chain con- 

 centrating solar energy for man's use. 



Water Quality . Even raw domestic sewage is over 99 per cent pure 

 water, but the infinitesimal amount of dissolved and suspended 

 material has effects far out of proportion to its magnitude. While 

 ocean water contains dissolved solids measured in concentrations of 

 "parts per thousand," water quality measurements, except for temper- 

 ature, are couched in terms of "parts per million" and "parts per 

 billion" whether thev are measurements of dissolved oxyaen, plant 

 nutrients, orqanic pollutants, toxic chemicals, or any of the other 

 parameters by which pollutional levels are characterized. 



Upon the very delicate tests by which such minute concentrations are 

 measured depends the quantitative knowledge of pollution and how to 

 control it. 



Nature of the Bottom . The land under the water in the estuarine 

 zone can tell much of the history of the water flowing over it. 

 Solids are deposited from the water on the bottom, and creatures 



