for carefully marked dredged channels; passage of anadromous fish 

 is blocked by polluted estuarine zones ; thermal discharges aflfect entire 

 ecosystems; diversion of rivers has caused salt water intrusion into 

 ground water; and untreated or inadequately treated municipal and 

 industrial waste discharges have damaged fisheries, added to silta- 

 tion, and made many areas unsuitable for the increasing recreational 

 use the present society demands. 



There was little awareness of the danger to future generations as 

 long as the ability of the natural environment to absorb the effects of 

 the socioeconomic environment seemed unlimited, and the problems of 

 pollution and environmental damage were isolated. But now, in the 

 second half of the 20th century, the entire Nation must face the 

 results of those 300 years of exploitation, and weld the three estuarine 

 environments into a national program to preserve, study, use, and 

 develop the estuarine zone. Action is needed now. The purpose of this 

 study is to recommend that action. 



The Study Directive 



The Congress, in passing the Clean Water Eestoration Act of 1966 

 (Public Law 89-753), section 5(g), directed the Secretary of the In- 

 terior to study the problems surrounding pollution of the estuarine 

 zone, and to make recommendations to the Congress for an effective 

 national estuarine management program in which the Federal, State, 

 and local governments, as well as public and private interests, will 

 have clearly defined responsibilities. 



The recommended program was to be based on a careful evaluation 

 of existing relationships among the three estuarine environments; 

 the effects of pollution on uses; and also the effects of demographic 

 and use trends on pollution of the natural environment were to be 

 considered. 



All existing pertinent information was to be assembled, coordinated, 

 and organized to serve as a factual base for the study, and additional 

 investigations and surveys were to be carried out to supplement exist- 

 ing information. The study was to be conducted in cooperation with 

 other Federal agencies. State and local governments, and other in- 

 stitutions and individuals. Everyone with an interest in the estuarine 

 zone was to be consulted. 



The report was to include not only the recommendations for a na- 

 tional program, but also an analysis of the importance of estuaries in 

 the economic and social environment and the effects of pollution on the 

 natural ecosystem. A discussion of the major economic, social, and 

 ecological trends was to show what the future might hold ; and rec- 

 ommendations were to be made for research and study to acquire basic 

 knowledge needed to manage future trends. 



EXTENT OF THE ESTUARINE ZONE 



The geographical scope of this study was stated in the Clean Water 

 Restoration Act in this manner: "* * * the term 'estuarine zones' 

 means an environmental system consisting of an estuary and those 

 transitional areas which are consistently influenced or affected by 

 water from an estuary such as, but not limited to, salt marshes, coastal 

 and intertidal areas, bays, harbors, lagoons, inshore waters, and chan- 



