1912 AND FISHERIES COMMISSION. 27 



sities, although their guilt has never scientifically been established. The 

 sucker, indeed, furnishes a good example of the comparative ignorance 

 of the attributes of many fishes at present existing, for while many 

 authorities and practically all commercial fishermen will unhesitatingly 

 classify the fish as a deliberate spawn-seeker and eater, other authori- 

 ties, including Dr. Forbes, and the well-known Provincial icthyologist, 

 Mr. C. W. Nash, disclaim this propensity on the part of the sucker 

 entirely. In fact careful examination of the stomachs of many suckers 

 taken on or in the vicinity of spawning beds failed to disclose any other 

 food than alga?, entomostraca and other low forms of animal life, while 

 Mr. Nash, who also made the interesting experiment of keeping suckers, 

 found that they refused at all times the spawn of other fishes, which was 

 offered them, although they would greedily devour algjB, earthworms 

 and various forms of insect life. 



Before the institution of commercial fishing on a large scale ap- 

 parently all the varieties of commercial fishes which now inhabit the 

 waters (with the solitary exception of the imported carp), existed in 

 them in great numbers, and it would appear, therefore, reasonable to 

 assume that each species must have been assisting, to some extent, in 

 preserving such a balance in the natural conditions prevailing below 

 water as to render these suitable, not only for its own prolific existence, 

 but for that of other varieties also; in fact, that a direct relationship 

 did exist between the welfare of one variety and that of the other. On 

 land the direct relationship between various forms of animal, insecti- 

 vorous and vegetable life is receiving yearly ever-growing attention, 

 some varieties being cultivated, preserved or introduced by reason of 

 their beneficial influence or combative powers against some particular 

 condition, while relentless war is being waged against other noxious 

 species, often at enormous expense, but justified none the less by the 

 great profit which it is known will accrue. Doubtless very similar con- 

 ditions prevail below water as on land, but they are not at present under- 

 stood. It is plain, however, that commercial fishery operations, when 

 conducted vigorously against certain species and less vigorously or not 

 at all against others, must sooner or later effect a considerable trans- 

 formation in the normal conditions prevailing below water, by disturb- 

 ing the natural balance. That this might easily result in a great increase 

 in the numbers of more or less commercially useless varieties, such as 

 the sucker, is but all too obvious, and if these fishes actually possess the 

 harmful spawn-eating propensities attributed to them by some authori- 

 ties, the direct baneful influence of their rapid multiplication on the 

 numbers of the finer fishes can be readily appreciated. On the other 

 hand, it is equally obvious that even such a fish as the sucker has its 

 place in the scheme of nature, for it is well known that they were in 

 great abundance when the white man first entered the country, so that, 

 although in view of the effects of commercial fishing on the fisheries at 

 large it might well be advisable to take steps to decrease the numbers of 



