THE OCEAN: ITS POTENTIALITIES AND PRODUCTS 5 



lime to form their shells or bones and thus remove quantities of carbon dioxide, 

 phosphate, and lime from the sea water. They also absorb nitrogen compounds 

 and oxygen. When these animals die, they decompose, giving off carbon dioxide, 

 ammonium salts, and water. The calcium carbonate and phosphate of their shells 

 and bones are deposited on the ocean floor. 



The Chemical Wealth of the Ocean 



As the ocean contains an enormous quantity of most of the pure and combined 

 elements, among them valuable inorganic salts, it is surprising that so few of 

 these substances can be obtained for industrial use. At present the only mineral 

 products taken in quantity from sea water are salt, magnesia, magnesium, mag- 

 nesium salts and other magnesium products, and bromine and small amounts of 

 potassium salts, iodine, and calcium salts. 



Is it possible to exploit the vast quantity of valuable chemicals in the ocean? 

 To do so it is necessary to develop new methods which will not require the 

 evaporation of a large proportion of the water. Taylor (1932) has indicated that 

 gold and other heavy metals can be taken from sea water by kaolin or alumina 

 jelly. Perhaps a system of ion exchange may soon be developed which will make 

 possible the recovery of many metals and other inorganic materials of great value. 



One of the great industrial developments which occurred during World War II 

 was the large-scale recovery of magnesium from sea water (page 41) . In addition, 

 the processes of recovering bromine from sea water were greatly improved. These 

 advances may be the forerunners of other marine chemical industries. 



The Ocean Floor 



The floor of the ocean is strewn with glacial rocks, fossilized bones and teeth 

 of ancient animals, old shells, sedimentary remains of tiny organisms of silica, iron, 

 and calcium, mixed with sediments and precipitated insoluble matters, and pumice 

 stone and volcanic dust, which in the course of time are compressed to form dense 

 rock. During the centuries the shells, teeth, and bones have become encrusted 

 with deposits of manganese and iron oxides, phosphates, and, in some cases, 

 barium sulfate. The phosphate concretions sometimes contain as much as 20 

 to 24 per cent P2O5. 



As sea water is a depository for soluble salts, the floor of the ocean is no less 

 significant as a depository for chemical substances insoluble in water. In fact, the 

 ocean floor records a large part of the geological history of the world. 



Biological Aspects 



Sea water contains inorganic nutrients in approximately the same proportions 

 to which living things are adapted. It also contains a huge amount of living and 

 dead organic matter (5 mg per liter, or one part in 100,000). Although this may 

 not seem like much, it amounts to 22,800 tons per cubic mile. Some of this organic 

 matter is brought in by the rivers, and much comes from the plants and animals 

 that live in the ocean. When these organisms die, they disintegrate and their 

 body substances diffuse in the water. 



The ocean receives nearly 71 per cent of all the radiant energy coming from 

 the sun to the earth's surface. Solar energy is absorbed at and near the surface 

 of the ocean and is used by minute plants, floating mostly in the top 25 fathoms, to 



