1-2 EDWARD VII. 



SESSIONAL PAPER No. 22a 



A. 1902 



II 



THE EFFECTS OF POLLUTED WATERS ON FISH LIFE. 



A PRELIMINARY REPORT BY PROFESSOR A. P. KNIGHT, QUEEN'S 

 UNIVERSITY, KINGSTON, ONT. 



Before entering upon my formal report, I wish to express to the Dominion 

 Government, through Professor Prince, the Commissioner of Fisheries and Director of 

 the Marine Biological Station, my warm appreciation of the foresight and spirit which 

 prompted the establishment of a marine biological station in Canada. I have no doubt 

 that every year will demonstrate the wisdom of founding such a station. The privilege 

 accorded me at it, during the past two seasons, in the way of collecting and studying 

 marine and fresh-water animals, has been a source of keen enjoyment. The following 

 report is tendered in the hope that the facts submitted may help, in a humble way, to 

 elucidate some of the problems which are presented to the Dominion Fisheries Depart- 

 ment from time to time for solution. 



It was Professor Prince's report for 1899 to the Honourable Sir Louis Davies which 

 suggested the inquiry described in the following pages. Its prosecution at St. Andrews, 

 last summer (1900), was greatly aided by the assistance and advice which I received 

 from the Commissioner and I desire to make public acknowledgment of the same. 



The pollutions with which I experimented were (a) sawdust, {h) waste water from 

 a nail factory, (c) waste water from two pulp mills, and (o?^ waste water from gas 

 works. 



The general method of investigation consisted in adding varying percentages of the 

 waste water to fresh water, or to salt water, according to the kind of fish experimented 

 with, and then immersing the living fish in the mixture, and noting the effects upon 

 them. 



A 'control' experiment was usually carried on along with those on the waste 

 water. This ' control ' consisted in placing a normal vigorous animal in unpolluted 

 water, so that observations on fish immersed in the polluted water could be compared 

 with observations upon the animal in normal water. 



PRELIMINARY EXPERIMENTS. 



Some preliminary experiments were undertaken for the purpose of determining, 

 first, the shape of the vessel in which the fish should be confined, and secondly, the 

 volume of water which should be used in proportion to the weight of the fish. Infor- 

 mation was needed as to whether the dishes used should be broad and shallow, or tall 

 and narrow ; also whether large quantities of water should be used in proportion to the 

 bulk of the fish, or whether smaller quantities might suffice. 



The following experiment repeated a number of times settled the first point. Two 

 rock bass (i477?6^o/?Zi^esrwpes^ris,Rafinesque) of equal weight, were placed in separate vessels, 

 each vessel containing 3J litres of lake water. One vessel was an ordinary agateware 

 baking pan, 13J inches long, 9 J inches broad, and If inches deep. The other vessel 



9 



