Oshurn. — Conditions Detrimental to Bn -is. 33 



turer, the miner and many other producers, while atthesame 

 time they have worked great detriment and often made im- 

 possible the productivity of the water in the vicinity of their 

 operations. 



The important human checks on the productivity of our 

 waters are (1) pollution, (2) interference with the water 

 supply and (3) over-fishing; these three, and the greatest of 

 these is pollution. I shall not need to consider the pollution 

 question at this time, for it has been discussed already and 

 we are all of one mind that it has wrought more damage to 

 our waters than all other things combined. The voters of 

 the country have the solution of this matter in their own 

 hands, but until they awake to the fact that there are more 

 important things in the world than to find the easiest way to 

 dispose of refuse and waste by dumping them into the water, 

 the menace will continue to grow. The individual in the 

 city is compelled to install plumbing and take other meas- 

 ures to care for household wastes and it is just as logical to 

 expect the manufacturer, miner, canner, etc., etc., to care for 

 his industrial wastes. It may make the products of indus- 

 try cost more to the consumer and it may reduce the income 

 of the producer somewhat, but there are some natural rights 

 of all the people valuable beyond price and pure water is 

 one of these. Pollution is the one absolute check on fish 

 production, though fish production is only one of the ques- 

 tions involved in the pollution problem. 



Interference with the water supply is another important 

 menace to fish production, and this again is charged to the 

 score of human industry. Deforestation is perhaps the most 

 imxportant phase of this problem. It is a common experience, 

 obsen^able everywhere in the more populous sections of our 

 country, that the streams and lakes no longer maintain their 

 original levels throughout the year. At the same time 

 floods are higher and more destructive with the passing of 

 the years, since there no longer exists the natural means of 

 holding back the rainfall until it sinks into the soil. Streams 

 that only a generation or so ago were good fish streams 

 now become so low in dry seasons that game and food fish 

 cannot live in them at all or only in more limited numbers, 

 for the productivity of any body of water is measured not by 

 the condition at its best, but at its worst and it will produce 

 only such forms as will find cover and sustenance at its low- 

 est stage. Reforestation of the hill tops and steep slopes 

 will aid in stream recovery and the reduction of floods, and 

 should be a part of every fish conservation program. 



The cleaning up of stream and river bottoms is another 

 factor in this problem. The brush and fallen tree trunks 



