24 



of the cities and industries in the coastal counties dispose of wastes 

 either directly or indirectly into the estuarine zone. 



Liquid waste discharges to estuarine systems include domestic waste 

 prouciOta, inuustriai waste materials of all degrees of chemical com- 

 plexity and sophistication, used cooling water with its thermal load, 

 and storm runoff. These wastes affect the estuarine environment in dif- 

 ferent ways and can eliminate other uses. 



Liquid wastes are not the only concern. The use of the estuarine 

 shoreline for refuse dumps and land fills results in considerable debris 

 getting into the water ; water leaching through these dumps has a pol- 

 lutional impact on the estuarine water. Spoil disposal from dredging 

 activities is another form of solid waste material that contributes to 

 estuarine degradation, and solid materials entering the estuary in the 

 form of debris from storm runoff can be significant in terms of damag- 

 ing beneficial uses. 



Waste disposal is a highly significant and universal use of the 

 estuarine resource and it is likely to remain so. Along with the many 

 other socioeconomic uses of the estuarine environment, it must be man- 

 aged so that it does not damage the biophysical environment. 



Exploitation of mineral resources 



Minerals within the water, on the bottom, and under the bottom are 

 a valuable part of the estuarine resource and are being exploited 

 widely. 



Subbottom mining operations are limited to the recovery of sulfur, 

 petroleum, and natural gas, with the major operations occurring in 

 Louisiana, Texas, California, and Alaska. These operations exist both 

 in the estuaries and out on the continental shelves with the governing 

 criterion for locating being the location of reserves. 



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 

 universal throughout coastal areas wherever suitable deposits and 

 a market exist. 



Oyster shell is an extremely useful construction material in the Gulf 

 of Mexico biophysical region. Twenty of the 22 million tons of annual 

 U.S. production are in the Gulf States with Texas and Louisiana pro- 

 ducing the vast majority of it. 



Phosphate rock is an important estuarine mineral resource; about 

 75 percent of the total U.S. production is in the estuarine zone of Flor- 

 ida and North Carolina, particularly around Tampa Bay and Pamlico 

 Sound. 



Aqvuculture 



The great fish and shellfish resources of U.S. coastal waters 

 have adequately supplied the seafood demands of the increasing popu- 

 lation for over 300 years. Now, however, the demands for some prod- 

 ucts is so great that the normal fishing grounds and fisheries are in 

 great danger of being exhausted, both from overfishing and from the 

 indirect effects of man's enroachment into the estuarine environment. 

 To supply future needs of some fish products new approaches toward 

 commercial fishing are needed, both in harvesting the natural growth 

 and in controlling the entire fishery. Aquaculture is defined as the 



