Atomic Radiation and Oceanography and Fisheries 



others are employed indirectly in pharmaceutical 

 and food products. 



Petroleum and natural gas 



It is estimated that about 30 million cubic 

 meters of possible oil-bearing sediments underlie 

 the 11.8 million square miles of the submerged 

 continental shelves. These sediments contain 

 some 400 billion barrels of recoverable crude 

 oil. 



Exploitation of these deposits of petroleum 

 and the associated natural gas has commenced in 

 the waters of the Gulf of Mexico; intensive 

 geophysical prospecting has been conducted off- 

 shore from California and in the Persian Gulf. 

 It may be expected that this source of fossil fuels 

 will be extensively utilized in the near future. 

 The resource is confined to the subsoil of the 

 marginal seas, since only there do we find oil- 

 bearing sediments. 



Minerals 



Extraction of sea salt for sodium chloride is 

 an ancient industry, and is now highly developed 

 also for production of sodium sulfate, potas- 

 sium chloride, and magnesium chloride. Bro- 

 mine is extracted directly from sea water for the 

 manufacture of ethylene dibromide. Magnesium 

 metal has been produced commercially from sea- 

 water by chemical and electrolytical procedures 

 for nearly two decades. 



All of these industries use sea water taken 

 from near the surface at the shore but the 

 quantity of water utilized is insignificant. For 

 example, a single cubic kilometer of sea water 

 contains over a million tons of magnesium, 

 about five times the peak world annual produc- 

 tion of this metal. 



The floor of the deep sea is known to contain 

 low-grade deposits of cobalt, nickel and copper 

 (0.1 to 0.7 per cent by weight of the metals) 

 associated with deposits of iron and manganese. 

 The problems of mining these materials, in the 

 face of the great depths and pressure, have not 

 been solved, and they certainly will not soon 



be economically useable. 



\ 



Ocean transportation 



Long-distance transportation of large cargos 

 by sea is the indispensable basis of international 

 commerce. The economy of the United States 

 and of other industrial nations is in large part 



dependent on the sea-borne commerce that flows 

 through the seaports. 



Contamination of the sea by nuclear wastes 

 will certainly not present a hazard to shipping, 

 since acceptable levels of such materials in the 

 surface layer of the sea will be limited by other 

 considerations (such as the effects on the fish- 

 eries) to much lower levels than would consti- 

 tute a hazard to ships' personnel. On the other 

 hand, it is almost certain that nuclear power 

 plants will be extensively used in merchant ves- 

 sels; they are already in use in naval craft. 



Serious hazards may arise in confined waters 

 from collisions in which the reactor is damaged 

 and the fuel elements with their contained fis- 

 sion products are lost in the water. Suppose for 

 example that a 50,000 kilowatt reactor (prob- 

 ably fairly typical for a large fast freighter) 

 has been in service without refueling for one 

 year on a ship that has spent half its time under 

 way. Approximately 10 kilograms of fission- 

 able material will have been used up and the 

 total amount of fission products will be ap- 

 proximately 10^ curies. If, owing to a collision, 

 the reactor is lost in a harbor, say 8 miles long 

 by 3 miles wide by 50 feet deep, and the fis- 

 sion products become uniformly distributed, the 

 water in the harbor would contain 10'^ curies 

 per cubic meter giving an almost constant radia- 

 tion dose of about 0.5 r per day on the surface. 

 Dock pilings, ship bottoms and other structures 

 covered with fouling organisms would accumu- 

 late a much higher level of radioactivity, and 

 local concentration in the water might be ex- 

 tremely high. 



Recreation 



For coastal populations in the temperate, sub- 

 tropical, and tropical regions, the sea and its 

 contents provide healthful sports and satisfac- 

 tion of men's curiosity and their desire for 

 beauty. Boating, swimming, sport fishing, and 

 other recreations are engaged in by millions of 

 people, and are the basis of tourist and service 

 industries of very considerable monetary value. 



JV^aste disposal), 



Disposal of domestic sewage and industrial 

 wastes is often conveniently accomplished near 

 coastal population centers by running them into 

 the sea. The large volume and rapid mixing of 

 the ocean waters dilute the wastes, and the bac- 



