CONSERVATION OF INLAND FISHERIES 85 



independently of the departments of public health, in whose hands I 

 believe all matters pertaining to factory effluents are placed. These 

 latter consider only human life and ignore fish and other aquatic 

 creatures. 



So much for pollution. Now let me for a few 

 in Ri'er*"*"* moments call your attention to another obstacle to 

 conservation, that of obstruction to the free passage 

 of fish when going to, or coming from, their spawning and feeding 

 grounds. Nothing appears to me to be easier in a new country, where 

 riparian and vested interests are only just commencing to be acquired, 

 than to frame legislation to prevent this new trouble. We have 

 already excellent laws demanding fish passes where dams are erected, 

 but these laws do not appear to be always put into force or, when they 

 are, the constructor of the dam is left to erect the fish-pass in any way 

 he thinks fit. It is often due to the fact that the erection of the dam 

 is not reported to the Fisheries Department. What is the result i" 

 Some of these fish-passes might be useful, if dry, for assisting hens 

 to go to roost, others might be useful for aerating water in substitution 

 for soda water. In any case the requirements of the fish appear to 

 be seldom considered. In fact, the basic principle of fish-pass con- 

 struction is entirely overlooked. Surely the time has arrived when 

 the Fisheries authorities should deal with these matters themselves, 

 and compel any constructor of a mill-dam to erect a pass according 

 to approved designs, and also to maintain it so long as the dam is in 

 existence. In my opinion no dam or weir should be permitted without 

 a license being issued by the Fisheries Department, and such license 

 should contain the necessary contract with reference to the building 

 and maintaining of the fish-pass. The effects of such obstructions on 

 a river are many, but the chief results are isolation of the spawning- 

 grounds and crowded " redds," the latter a very serious menace to 

 natural incubation. 



I need not deal further with this subject but will 

 Artihci^ proceed to the effect of artificial incubation on con- 



servation. I do not wish to touch too prominently on the 

 benefits of the artificial stimulation of conservation, for that is outside 

 my subject in this address. What I wish to touch upon principally, 

 is the often injurious effect of artificial incubation on our fisheries 

 when not administered with considerable forethought and knowledge. 

 The basic principle of artificial fish culture should be to correct the 

 natural balance disturbed by artificial agencies. In fish culture we 

 are apt to look on the side which superficially seems to be the right 

 one, 1)ut we quite overlook the result on natural balance, to which I 



