CONSERVATION OF INLAND FISHERIES 83 



It is not fully appreciated that, taking the same species of fish as 

 an example, the natural periods of gravidity vary under different local 

 influences, such as temperature, food supply and environment. Thus 

 it is surely improper to enact legislation enforcing an artificial so-called 

 close season without due consideration of these factors. The remedy 

 is not far to find. Would it- not be possible to divide our country, so 

 far as fishery administration is concerned, into watersheds where con- 

 ditions are nearly akin? This would surely be more advantageous to 

 the fish than the present method of having a universal close time over 

 a whole province. 



Let me give as examples only two instances of these varying 

 periods in the province of Ontario. On the west shore of the Saugeen 

 or Bruce peninsula the lake trout (Cristivomer) comes on the "redds" 

 a fortnight earlier than it does on the southeast shores of Georgian 

 bay. Again, in lake Nipigon, the speckled trout becomes gravid 

 nearly a month later than it does in the river flowing out of it. 



Now let us look into the question of legislation affecting the mesh 

 of nets and its relation to conservation. In framing regulations 

 governing the size of the mesh in a net, the framers have or should 

 have two points before them. First, they must allow the mesh to 

 liberate all immature fish. I go further than this, and say they should 

 allow every fish the opportunity to reproduce its species at least once. 

 Secondly, they should insist, if possible, on the use of a mesh that will 

 certainly trap aged fish that have become a menace to the fishery. 



To illustrate my meaning I would say that it is stated that, in 

 certain waters of this province, it is impossible to catch by means of a 

 net, the large lake trout that have become a menace to other fish in 

 the district. Why is this so? Is it not because the fishermen have 

 become wedded to a four-inch mesh? Would it not be possible to 

 regulate this otherwise in order to catch these cannibal fish during the 

 most suitable period for getting them? Fish culturists would like 

 to have those large fish caught, for as brood stock they are not so 

 valuable as the more vigorous, medium-sized fish. 



„ „ . The next factor affecting conservation is pollutions 



Pollution, . ,.,.,,,. 



Mechanical of two types, that is, mechanical and chemical. 



and Chemical Pf Townsend of the New York aquarium has said 

 that all our fish commissioners of experience are agreed that the 

 decrease in the supply of our food fishes is traceable more to pollution 

 than to any other cause and that, further, stream pollution is going on 

 at a rate proportionate to the increase in population and the develop- 

 ment of manufactures. The condition would not be so serious in 



