9 



fish and wildlife which are the ultimate life forms in the manless 

 estuarine environment. 



Solar radiation and gravitational forces control the natural environ- 

 ment through a complex series of mechanisms. In the estuarine zone 

 this control exhibits itself through seven major environmental factors 

 that exist throughout the estaurine zone. 



(1) 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. 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; 

 its width and general configuration along the U.S. coastline affects 

 the force with which ocean waves strike the shore and consequently the 

 manner and degree of shoreline erosion and accretion (fig. IV. 1.1). 



FIGURE IV.1.1 MAJOR OCEAN CURRENTS AFFECTING THE UNITED STATES 



Continental Shelf 



potyoonc proJACtion 



