American Fisheries Society 105 



America has to contend at the present time is the con- 

 tamination of public waters by sewage and the refuse of 

 manufacturies. Although the propagation of fishes by- 

 artificial means has, in this country, reached a degree of 

 efficiency unequaled in other countries, the preservation 

 of streams in conditions desirable for the maintenance of 

 fish life has been singularly neglected. 



In a majority of those States which possess fishery 

 resources there exist more or less effective restrictions 

 upon fishing and the operation of fishery industries, but 

 it is seldom that enactments against the depositing of waste 

 matter in the waters are enforced. 



All our fish commissioners of experience, both na- 

 tional and state, are agreed that the decrease in the sup- 

 ply of food fishes is traceable more to the pollution of 

 waters than to any other cause, and stream pollution is 

 going on at 'a rate proportionate to the increase in 

 population and the development of manufacturing in- 

 dustries. The effects of pollution are most serious in 

 the more densely populated states. It begins almost at 

 the sources of streams and extends to the very mouths 

 of the largest rivers. 



The conditions would probably not be so serious in 

 their effect upon the supply of fresh-water fishes had not 

 the flow of streams been lessened by deforestation. 

 With the cutting away of forests and the cultivation of 

 the land, the summer temperature of streams has become 

 higher and the breeding grounds of game and food fishes 

 covered by silt washed down by floods. 



The pollution of streams not only affects sport and 

 commercial fishing, but the all-important matter of 

 public health. 



The agencies at work are almost too varied for 

 enumeration. In general the pollution of waters is 

 caused by sawmills, pulp and paper mills, tanneries, 

 starch, cheese and sugar factories, gas, wood alcohol, 

 chemical, glass and dye works, oil refineries, distilleries 



