IV-319 



Bay. It seems reasonable to conclude that as urban areas continue to 

 grow through suburban expansion, as land values rise and as zoning 

 restrictions are tightened, that the demand for estuary reserves of 

 sand, gravel, and shell will grow. Offshore dredging on a massive 

 scale is presently precluded due to the high cost of building suitable 

 dredges, technological difficulties of deep water recovery, and com- 

 peting resources on land and the estuaries. 



Salt is an obvious yet relatively Insignificant product extracted 

 from estuarine water. Only three of over one hundred salt producing 

 operations are located in estuarine areas. Their total production 

 in 1967, valued at $17 million, was about 7 percent of the total U.S. 

 production. Such activity in estuarine areas is bound to decline as 

 pressure is exerted by more competitive uses of estuarine land. 



Current interest in exploiting phosphorite and manganese nodules and 

 contiguous deposits of nickel, cobalt, and copDer is limited by avail- 

 able technology. Gold and platinum metals exist in submerged beach 

 and placer deposits off Alaska, California, and Oregon but it is un- 

 likely that mainlng will be undertaken for them in the near future. 

 Diamonds, gold, and zircon have also been Identified in the estuarine 

 sands of various States, but extraction appears unlikely. 



Magnesium metal, magnesium oxide, and bromine are all extracted from 

 seawater and plants are presently located mainly in the estuarine zones 

 of Texas and California. Production is adequate for projected demand 



