7-) 



sj'stem and may work damage that cannot be 

 repaired. Estuarine pollution has a more far- 

 reaching, although perhaps less visible im- 

 pact on our national life than the pollution 

 of streams and rivers. Action to abate oceanic 

 and lake pollution has lagged behind the 

 abatement of river pollution, because marine 

 problems are more comjilex. 



Marine pollution takes many forms. Munic- 

 ipal sewage, a notorious source, still is one of 

 the simplest to treat, although the waste 

 treatment problem is becoming increasingly 

 complicated. Industrial wastes are difficult to 

 treat. In many cases, sewage treatment plants 

 are of no use, because certain industrial 

 wastes neutralize the chemicals used in the 

 treatment process. However, industrial wastes 

 are generated at known and fixed locations, 

 and at least they cp„n be identified by source. 



The most difficult pollution control prob- 

 lem is posed by wastes which do not come 

 from a point source : chemicals spread on icj' 

 roads; pesticides, herbicides, and fertilizers 

 sprayed in fields; lead oxide in the exhaust 

 of automobiles. These also find their way to 

 streams, to rivers, and eventually to the ocean 

 in ever larger amounts. Some experts think 

 that such pollutants are even more danger- 

 ous than the more readily identified munici- 

 ])al and industrial wastes, but data to evalu- 

 ate this view are grossly inadequate. 



Physical modifications also may lie classed 

 as pollutants. Physical changes may lie benefi- 

 cial or deleterious. The heating of coastal wa- 

 tei'S by the electric power industry provides 

 an example. "Warmer water may improve an 

 area's recreation ix)tential, and it also may 

 stimulate aquaculture programs. However, 

 increased temperature decreases the oxygen- 

 carrying capacity of the water and may 

 change the ecology of the area. 



Quito often marine acti^nties pollute the 

 marine environment. A dredging operation 



pollutes the water as it stirs up the bottom 

 silts. Oil spillages and boat toilets are two 

 of the most publicized sources of marine pol- 

 lution. There are more than 12,000 oil wells 

 oif the U.S. coasts, and the number is increas- 

 ing by more than 1,400 per year. Despite the 

 careful safety measures of the industry, well 

 blowouts, pipeline leaks, operator careless- 

 ness, and storm damage still can cause serious 

 damage. The total number of boats with 

 toilets in the United States is estimated by 

 the Department of the Interior to be 1.3 

 million. 



One of the least understood processes of 

 pollution is the manner in which organisms 

 concentrate pollutants. In a natural environ- 

 ment, oysters accumulate zinc and copper in 

 concentrations several million times greater 

 than found in sea water. Marine animals also 

 may concentrate manmade chemicals. Con- 

 centrations of DDT have been found in com- 

 mercially important fish. Excessive levels of 

 radioactive phosphorous have been found in 

 seagulls off the mouth of the Columbia River ; 

 the jDhosphorous was traced to nuclear plants 

 at Hanford, Wash., 300 miles upstream. Sig- 

 nificant quantities of a known cancer-causing 

 petroleum derivate have been found in mus- 

 sels in France. 



To many the oceans are the ultimate re- 

 pository of all pollutants. The oceans' ability 

 to assimilate waste material is immense; for 

 every i?erson on earth there is the equivalent 

 ocean volume of one square mile, 500 feet 

 thick. But the oceans are not infinite, and 

 they must not be considered the ultimate solu- 

 tion for waste disposal problems. 



Objectives for Pollution Control 



The first signs of pollution in a body of 

 water are rather subtle, and a strong public 

 reaction usually does not set in until pollu- 

 tion becomes intolerable. By this time, it is 

 very difficult to slow down the process, let 



