IV-137 



(Figure IV. 2. 24). This example is an exception to general practice, 

 but nevertheless points out the resource exploitation is not 

 necessarily synonomous with environmental destruction. 



Recovery of minerals from submerged estuarine zone bottoms by surface 

 mining, i.e., dredging, is primarily directed toward sand, gravel, and 

 oyster shell production. Sand and gravel operations are prevalent 

 throughout coastal areas wherever suitable deposits and a market exist. 

 Most sand and gravel dredging operations supply nearby users; therefore, 

 they tend to be distributed in relationship to construction and to 

 population. 



The concentration of population and industrial development in the 

 estuarine zone, the accessibility of estuarine areas for sand and 

 gravel dredging, and the efficiency of barge transport to coastal 

 construction areas all tend to increase the pressure on submerged 

 estuarine sand and gravel deposits, particularly as coastal shore 

 deposits are exhausted. While no data are available on the present 

 relative importance of shore and submerged deposits in the various 

 biophysical regions, it is certain that all available sources of 

 sand and gravel deposits will be exploited intensively. 



Oyster shell production is an extremely useful construction material 

 in the Gulf of Mexico biophysical region. Twenty of the twenty-two 

 million tons of annual U.S. production are in the Gulf States with 

 Texas and Louisiana producing the vast majority of it. The major 



