SYMPOSIUM ON SCIENCE AND PJICONSTRUCTIGX 31 



environments for breeding food lishes. and a host of other 

 similar questions came up for attention among those who 

 were preriouslv working on such pi'oblems and also forced 

 themselves upon the notice of othei^ who had not before 

 been concerned in the study of applied ichthyology. 



As this field of investigation was being -brought more 

 fully to the attention of biologists, one factor which had 

 previously been emphasized without having won effective 

 notice attracted general attention as of distinct importance, 

 Polltition of our streams by domestic and industrial wastes 

 had often been pointe^l out as a source of damage to the 

 fish life and thus, indirectly, to the general public. So 

 long as food was abundant and the loss cotild be replaced 

 readily by food supplies drawn from other sources, the sig- 

 nificance of the draft upon the nation by reason of the 

 pollution of its waters did not seem to demand particular 

 attention. Under the changeti circumstances the loss be- 

 came significant and the situation was still further modi- 

 fied in an unfavorable way by another factor. As neces- 

 sary adjuncts of war activities, numerous plants for the 

 manufacture of chemicals had sprung into existence. 

 Utilizing processes marked by their efficiency in terms of 

 time rather than by their ultimate effectiveness, they were 

 paying no attention to the by-products that were produced 

 in connection with the main processes, and were dumping 

 into streams enormous quantities of chemical substances 

 that exerted conspicuous and serious eft'ects on the life of 

 the waters. Attention was thus still more forcibly directed 

 to the need of controlling waste products and avoiding the 

 damage produced by them. The opportunity aff'orded for 

 scientific study was great, but few were free to take up the 

 problems intensively and the desired results are evidently 

 to be looked for in the future rather than immediately. 

 The urgency of war production was in many minds a suffi- 

 cient answer to the complaint of loss restilting from the 

 situation, and while some record has been made of the 

 losses incurred both in the industries themselves through 

 the wastage of valtiable by-products and to the public in 

 general through the destruction of areas adapte<:l to the 

 propagation and growth of food fishes as well as in various 

 other ways that are indirect, though very real, it is only 

 now that conditions are really favorable for investigating 

 the ways in which the loss can be jirevented and the pollu- 

 tion cleaned up. 



