86 PISHES AND PISHING IN SUNAPEE LAKE. 



once abounded in the lake; chubs usually abound in such favorable 

 waters when their enemies do not preponderate; and pickerel were 

 formerly common. It may be mf erred, therefore, that black bass 

 have been a factor in producing their scarcity. In the case of the 

 perch and the pickerel the bass may have worked two ways : One by 

 devouring the fish themselves and the other by eating their food. 

 It is probable that when chubs were abundant they contributed a 

 great deal to the food supply of perch and pickerel. Being deprived 

 of this food, they were driven to other scarcer food, or to food obtain- 

 able with greater difficulty, which would tend toward their diminution 

 in numbers. 



Then there is the indirect effect on other fishes to be considered, as 

 weU as the direct effect on some of them. Pickerel and perch, for 

 instance, driven to other food, would eat more of other fishes that 

 they did not previously attack so extensively, or else they would 

 deprive other fishes of food perhaps already scarce. Thus it may be 

 seen that the direct and indirect effects of introducing nonindigenous 

 fishes may be far reachmg, as has already been pointed out. 



As already suggested, it is impossible to state definitely the effects 

 of the introduction of the fish. But it has been shown that certain 

 fishes have almost completely disappeared, or have become very 

 scarce as the black bass increase in numbers and size. But there is 

 another thing that almost inevitably occurs in such instances. The 

 fact that a fish exterminates any other fish indicates that the par- 

 ticular exterminated form was the most sought or the only one avail- 

 able. This food being exhausted, it has to resort to other forms 

 which are not so easily obtainable and to feeding upon its own young, 

 with the consequences that the introduced fish decreases in size and 

 diminishes in numbers. Judging from the foregoing reports of the 

 former abundance and size of black bass and the present comparative 

 scarcity and decreased size, it would appear that something like this 

 has happened to the black bass of Sunapee Lake. 



Pike Perch {Stizostedion vitreum). 



The pike perch is variously known in different localities as wall- 

 eyed pike, pike perch, dore, grass eye, yellow pike, blue pike, jack 

 salmon, salmon, white-eye, pike, and pickerel. It is a member of the 

 perch family along with the yeUow perch. Its natural geographical 

 range is the Great Lakes region, upper Mississippi, north to Assini- 

 boia and Hudson Bay region, east to Vermont and Pennsylvania, and 

 south to Georgia and Alabama. It is by far the largest species of the 

 family and the most important commercially. It attains as high as 

 20 pounds weight. 



