12 Conservation Department 



I. Stocking Policy for the Genesee River System 



By G. C. Embody, 

 Professor of AquicuJfure, Cornell U7iiversify 



It is desirable to have a well defined stocking i^olicy for each 

 drainage system of the State. One of the chief purposes of the 

 present survey has been the development of such a policy for the 

 Genesee river system. 



The Problem. — In the formulation of a stocking |)olicy, answers 

 to two questions have been souglit, namely : 



1. What kinds of fishes are likely to find conditions suitable for 

 reproduction, normal growth and the esca]ie of enemies? 



2. How many should be ])lanted in oi-der to utilize the water to 

 its fullest extent ? 



With reference to the first it is necessary to know what consti- 

 tutes suitable conditions for the various species ordinarily ])lanted. 

 ►Some of the important factors here concerned are the following: 

 water temperature ; oxygen, carbon dioxide content, and purity of 

 Avater ; character of bottom in relation to natural spawning ; bar- 

 riers to fish migration ; size of stream or lake ; current and shelter. 



Water Temperature. — This factor has a far reaching effect 

 u])on fish life ; it governs the rate of all physiological activities — 

 respiration, digestion, rii)ening of the sex elements, etc. — - and is 

 therefore a limiting factor in growth and reproduction. 



If a warm water fish, like the large-mouthed black bass or bull- 

 head, is put into a ])ond fed by cold spring water, it may live 

 there possibly with comfort but it will not grow at the normal 

 rate and ])robably will not s])awn even though other conditions 

 may be favorable. Likewise, a warm i)ond or stream may consti- 

 tute an ideal environment for the bass but if brook trout 

 (speckled) are added, they most likely will die from a series of 

 com])lications induced by the high water temi)eratures. 



In the case of warm water fishes we wish to know whetlKM- the 

 temperatures i-ange liigii enough to ennbh^ them to spnwn a1 the 

 jioi-mal s))awning date and to pei'init Ihe young to gi'ow 1o a 

 (h'sirnbh' size befoi-e winter. It is hardly neeessai'v to eonsich'r, 

 in the hititude of central New York, the possibility of streams 

 i\]](\ hikes beeoming too wnnn I'oi' them. Such species ns small- 

 moutlK'd and large-moutluHl bass, bluegill sunfish, bulllK^ad and 

 l)erch i-ange farther to the south where waters are much warmer 

 than hei'e. 



The ti-out sti-e;iin, howex'er, pi'csenls ;i <Iit'ferent ease. Here one 

 ascertains if the wnler 1emi)eratures on Ihe hottest summer days 

 ar-e too high 1o |)ernii1 li'out to live in Ihein and i'urnish good sport. 

 Thererore, in ordei' llwM li'oul ni;iy be i)hiee(l in a proper environ- 

 meiil, one musi know the teinperalure inaxiiini in all streams 

 showing possi})ilities in this dii-eetion. 



In the Genesee valley the highest summei' air tem|)ei-atui"es i-ange 

 from *JU to UG degrees F., but there are rarely more than a half 



