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THE EFFECTS OF POLLUTED WATERS ON FISH LIFE 13 



SESSIONAL PAPER No. 22a 



These observations corroborate in a general way those of Dr. Philip Cox on the smelt 

 {Osmerus mordax) and quoted in Professor Prince's report of last year. Any discrepancies 

 may be accounted for by the fact that the properties of waste water from pulp mills 

 differ at different stages in the manufacturing process. 



The chemical analysis of this waste water, made after my experiments were com- 

 pleted, and published in an appendix to this report, shows that the mill from which the 

 pollution came was a sulphite one. 



• EXPERIMENTS WITH WASTE WATER FROM THE GAS WORKS, ST. JOHN, N.B. 



This waste water is much more poisonous to fish life than the former, and kills 

 much more quickly. The very suddenness with which fish succumb to its effects indi- 

 cates that death results in some cases, from poisoning with the sulphuretted hydrogen 

 which the water contains. Confirmation of this view is afforded by the fact that if a 

 fish does not die in the polluted water during the first 24 hours, it will usually live on 

 in the pollution for several days. Besides, when a fish succumbs quickly, say in 10 to 20 

 minutes, to the effects of this gas, it could usually be resuscitated by transferring it to 

 pure water. Within 15 to 30 minutes after transference, the fish was as lively as ever, 

 especially if the water were agitated so as to increase the amount of oxygen dissolved 

 in it. 



The following were typical experiments. A Roccus americanus was immersed in a 

 5 p. c. solution of gas water in lake water, and in 20 minutes the fish was dead. Im- 

 mersed in a 2 p. c. solution, the same kind of fish survived about half an hour. In a 

 J p. c. solution the fish lived about half a day. 



Sticklebacks endured this poison a much longer time. Of two sticklebacks, placed 

 in solutions of ^ p. c. strength, one lived a day and a half, the other lived ten days, and 

 was then liberated. I had reasons for suspecting that the animal which died was not 

 healthy when the experiment began, if so, its death was merely hastened by the 

 pollution. 



Trout are very sensitive to the effects of this poison. At 4.45 p.m., July 21, I 

 placed a trout in -J- p.c. gas-waste water. In 10 minutes the animal was lying on its 

 side at the bottom of the vessel. As it was evidently moribund, it was removed to 

 fresh water which was? agitated by pouring water upon it from a height. In 10 

 minutes the animal had apparently recovered, and lay quietly and comfortably at the 

 bottom of the vessel. In half-an-hour more, it was very active, and frightened if any 

 one approached. 



A torn cod (Microgadus tomcod) was placed in ay^^ p. c. solution of this waste in sea 

 water. In a few minutes it wqis lying on its side and in 15 minutes it was on its back. 

 When returned to sea water which I agitated vigorously, the animal soon revived. 



Experiments with smelt {Osmerus mordax) gave exactly similar results in J p.c. 

 solutions of this waste in sea water. 



Fresh water forms like the rock bass and sunfish, and salt water ' chub ' {Fundulus 

 heteroditus) were much less affected. These forms were kept from two to three days in 

 the pollution (J p.c. strength), some dying within 24 hours and some surviving several 

 days. The explanation would seem to be two-fold. In the first place these fish are 

 constitutionally more resistant to pollutions of all kinds. In the second place the sul- 

 phuretted hydrogen in the mixture would largely diffuse into the air, and decompose in 

 the water in an open vessel during the first 24 hours. If the animal, therefore, 

 survived this period, it died later on through the poisonous effects of the other ingre- 

 dients of the waste, such as the sulphates and chlorides. 



The chemical analysis given in the appendix, and made after my experiments were 

 concluded, shows that this waste water is ' much more diluted than those ordinarily 

 met with.' In estimating, therefore, the poisonous effect of gas waste water, these 

 points must be kept in mind : first, the extent to which it is diluted with lake or river 

 water before leaving the works; secondly, its specific gravity, 1 00123 at 15° C. (water = 

 1) ; and thirdly, the volume of the river, stream or lake into which the waste is 

 discharged. 



