21. What are the primary pollutants found in the sea and what 

 are their sources? 



Man is the greatest contributor of pollutants, such as sewage, pulp- 

 mill wastes, fertilizers, soaps, detergents, radioactive wastes, synthetic 

 fibers, plastics, oils, tars, greases, and insecticides. Hot and cold water 

 discharged by factories and silt from dredging operations may also be 

 considered as pollutant. 



Radioactive wastes may be direct fallout, discharges from nuclear 

 power plants, or nuclear waste disposed at sea. 



Improperly treated municipal and industrial wastes, which have long 

 presented problems in lakes, streams, and rivers, are becoming increas- 

 ingly serious in nearshore oceanic waters. 



Agricultural chemicals, both fertilizers and pesticides, are carried 

 into the oceans by runoff and through the atmosphere. 



Future coastal installations of large nuclear reactors that use sea 

 water cooling could result in contaminants that would significantly af- 

 fect the marine environment and the life it supports. 



Gorsky, N. 



The Sea— Friend and Foe, Foreign Languages Publishing House, 



Moscow (Paperback), 1961. 

 National Academy of Science— National Research Council 



Oceanography 1966— Achievements and Opportunities, 1967. 



21 



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