IV-10 



SECTION 2. THE DOMINATING ENVIRONMENTAL FACTORS 



The diversity of the estuaries, bays, inlets, lagoons, marshes, and 

 other features which make up the estuarine zone presents a discon- 

 certing picture of apparent individual uniqueness and complexity 

 without evident unifying principles for technical and political 

 management. Such unifying principles do exist, however, and the 

 estuarine zone as an environment 1s governed by a small number of 

 often competing dominating factors, having interrelationships which 

 determine the nature of each individual estuarine system. Simi- 

 larities and contrasts among estuarine areas in different parts of 

 the coastline point out the limitations of technical management 

 in the various portions of the estuarine zone, and show the realities 

 of nature within which the managing political entities must work. 



CONTINENTAL SHELF 



The submerged land next to the continent slopes gently to a depth of 

 about 600 feet, then it drops more rapidly to form the deep ocean 

 basins (see Figure IV. 1.1). This fringe of slightly sloping sub- 

 merged land, which along much of the Atlantic and Gulf coasts would 

 appear quite flat to the naked eye, is called the "continental 

 shelf," and its width and general configuration along the coastline 

 of the United States is one of the offshore conditions affecting 

 the estuarine environment. 



