Titcomb. — Destruction of Obnoxious Fishes 21 



destroying fish. Advantage is now being taken of the 

 knowledge thus obtained to see how little copper sulphate 

 can be used to exterminate fish. 



The first attempt in Vermont to exterminate the in- 

 troduced species by the use of copper sulphate was made 

 at Silver Lake in the town of Barnard in October 1913. 

 So far as the writer knows it is the first attempt of its 

 kind anywhere. It would have been more satisfactory to 

 begin with a body of water of less area and shallower, 

 but it happened that the lake was drawn down to an un- 

 usually low level this summer, thus reducing its area 

 from about one hundred to sixty-five acres or less and its 

 depth some six or eight feet. At low water level the 

 maximum depth was twenty-five feet. It contained pike, 

 pickerel (Esox lucius), pike-perch, yellow perch and 

 horned pouts, all in limited numbers, and afforded rather 

 indifferent fishing. 



The copper sulphate was administered by dragging it 

 over the surface in gunny sacks. Two launches and a 

 number of row boats were employed for the purpose. At 

 the first attempt, 2700 pounds of copper sulphate were 

 administered, but this was not sufficient to kill all the fish 

 and at a second attempt 3600 pounds were administered. 

 The copper sulphate precipitates quickly. On each occa- 

 sion it took about six hours to administer the poison. 

 Dead fish began to rise the evening of the same day. More 

 rose the second day and some on the third day. 



It was hoped that all the fish in the pond had been 

 killed, but recent reports indicate that a few pike sur- 

 vived. 



This is the beginning of a movement to restore some of 

 the trout waters to their primeval conditions. 



With the changes rapidly taking place in the natural 

 conditions of our forest and streams, the trout streams 

 will naturally grow less in number. The ponds and lakes 

 will, if properly conserved, continue to afford recreation 

 and food supply long after many of the streams are dry 

 or are too polluted to permit of fish life. Upon these nat- 

 ural ponds and lakes, then, and upon artificial ponds and 



