CONSERVATION OF INLAND FISHERIES 87 



Correlation ■'' ^^^^ ^°'^ ^0 the question of the correlation of the 



of Aquatic various animals to one another, e.g., as food and 



Animals feeder, enemy and friend, host and parasite. We 



must have ever before us the^ law governing the survival of the fittest, 

 and if that species which man takes from the water is not of the 

 " fittest " in a biological sense, woe to those species that remain, for 

 in all probability the species abstracted assisted in maintaining the 

 balance and allowed all others to gain their necessary living. 



Let me give a very simple example of the disturbance of the bal- 

 ance in this manner. There are large quantities of burbot, or what 

 the fishermen call variously ling, lawyers or eel-pouts, caught when 

 lifting whitefish. Why are not these voracious fish in every case 

 destroyed? Or even purposely netted for? Are they not in many 

 waters gaining the upper hand? Do we not see shoals of these fish 

 constantly hovering on whitefish spawning grounds, clearing every liv- 

 ing thing around them? This fish is left because fishermen are too 

 lazy to bring it to shore, and until they are compelled they will not 

 do so. 



The balance may also be affected by the introduction as well as by 

 the abstraction of a certain species. We have an example of this in 

 Ontario, in the introduction of the carp. This fish, where it has be- 

 come established,. has appropriated certain waters and has driven out 

 certain other fish, such as the pike-perch or yellow pickerel and the 

 bass. This disturbance is not due to any cannibal habits of the carp, 

 but simply to its peculiar mode of feeding. 



Relationship Lastly, I come to the problems arising out of the rela- 

 PlantLife tionship between fish, their animal food, subaquatic 



and Soils plant life and soil geology. We all know that there 



are only two sources of food, whether it be for subaquatic life or other- 

 wise, namely, soil and the air, but no animal can derive direct benefit 

 from either. The plant must intervene in order to convert the primi- 

 tive sources into the necessary protein, carbohydrates, fats and min- 

 eral salts necessary to animal life. This inter-relation of the animal, 

 vegetable and mineral kingdoms is a study of absorbing interest, as 

 anyone who knows anything of animal husbandry will readily agree. 



As one of the interesting examples I may mention the almost cer- 

 tain association of speckled trout with a stream originating in and flow- 

 ing through the Carboniferous limestone and similar formations, for in 

 such a stream, you are certain to find large quantities of univalve mol- 

 luscs of the snail family, (Physa and Lymnaea). The soil conditions 

 of these formations suit certain plant life, which in turn is best adapted 

 6 



