Sbo. 13.1 



DOMESTIC FISH-BREEDING. 



271 



very best authorities in tlie country — Geo. Dawson, a great lover of pisca- 

 torial sports — gives, in the Albany Evening Journal, the following reasons 

 for the disappearance of trout from streams where they were abundant, 

 lie sa^-s : 



"Every one who has lived a score of years in the neighborhood of mountair. 

 or spring brooks remembers when, in such and such a stream, trout were 

 abundant, where scarcely one is now ever taken. ' "What has become of 

 them V is a question which every one has been asked, or has asked himself, 

 a thousand times. One says, 'Tliej' have been driven out by sawdust from 

 mills erected upon the stream.' Another, who lives where tanneries have 

 been erected, thinks ' the tan bark has killed or disgusted them.' Another 

 says, ' Since the alders which used to border the creek have been cut down, 

 and the forest cleared away, they liave sought greater solitude.' Others 

 say, ' They have gone because trout will not stay where there is a great deal 

 of passing to and fro, as there necessarily is in a thickly populated locality ;' 

 and others still insist that ' they have all been fished out.' Now, in my 

 opinion, not one of these reasons is real. Neither sawdust, nor tan bark, nor 

 clearings, nor dense population, nor excessive fishing, is tlie cause of depopu- 

 lation. Some of the very best trout streams that I know of are full of saw- 

 dust and tan bark. The bottom of Caledonia Creek is not only a bed of 

 sawdust, but the creek lies in the midst of a dense popidation, and has been 

 fished, night and day, for thirty years. Nevertheless, in its cold, crystal-like 

 water, trout are more plenty to-day, and more are taken, than ten years 

 since. I have been more than once surfeited with success in a stream in 

 Canada where the sawdust was so thick that it formed a compact covering 

 upon its surface ; and every year I take trout from a little brook in Comiecti- 

 cut which has been cleared and fished for almost a century. There arc three 

 great causes for the depopulation of trout streams : First, the erection of 

 establishments upon them in which lime is largely used ; second, the intro- 

 duction into the streams of pike or pickerel, whose voracity is, sooner or 

 later, fatal to all competitors; and thirdly, and principally, the gradual 

 cliangc of the temperature of the water. Trout will not live long in water 

 which is not, at all seasons, of a temperature which may not, in comparison 

 with other water, be characterized as cold. Other causes besides those I 

 liavc named sometimes operate; but, in ninety-nine cases out of a hundred, 

 the changed temperature of the water is tlic cause of the absence of trout 

 from streams where they were once abundant." 



lie does not give the reason of this change of temperature, but wo do : it 

 is just the difference between a cool forest shade and a broad expan>e of hot 

 sunshine. Where tiiese mountain streams once were sliaded from the first 

 gushing spring to their montlis at some large river, they arc now exposed to 

 the full force of the noonday sun, until tlic water is heated to a degree as fatal 

 to the brook trout as ice would be to a tropical plant. The streams that still 

 retain trout are those which are so largely supplied with cold spring water 

 that the temperature is kept at a healthy point, notwithstanding the denuded 



