24 Conservation Department 



Total weight of all fish recovered, 7.7 lbs., or at the rate of 45.43 

 lbs. per acre. Minnows and suckers made u]) al)0iit 70 percent of 

 the total Aveig-ht while rainbow trout and brown trout constituted 

 the remainin<i' 30 percent. There were 1 yearling browai trout, 

 100 rainbow fingerlings of the 1928 hatch and 64 yearlings and t^vo- 

 year-olds. Sixty percent of the rainbows were small fingerlings 

 about two months old ; about 27 percent were yearlings and an esti- 

 mated 13 percent, two-year-olds. All trout except three of the 

 two-year-olds were under six inches long. Hence only three or 

 slightly more than one percent of the trout population in nearly 

 one-fifth of a mile of stream were at this time (June 20) available 

 to fishermen. 



Further explanation and discussion must await future studies. 

 The work represents a comparatively ncAV line of attack upon 

 that big and practically untouched problem of stream production 

 w^hich is one of the most important considerations in developing 

 a stocking policy. 



A Change in Policy for Rainbow Trout. — In past surveys, 

 it has been recommended that trout of this species be planted in 

 certain of the larger streams and in others tributary to lakes and 

 reservoirs ; this because eastern rainbows some time before the 

 third year, tend to migrate dowaistream into such bodies of water 

 where they groW' to sex maturity. If these particular conditions 

 do not exist, they simply migrate out of the stream and are appar- 

 ently lost. However in a great many streams too warm for either 

 brook or brown trout and which do not flow into reservoirs, we 

 have found rainbows varying in size from fingerlings up to 9 

 inches long. Those above 6 inches rise freel}' to the artificial fly 

 and furnish good sport in streams which otherwise would not 

 contain game fishes of any kind. A case in point is Elton creek 

 which yielded several 2-year old rainbows in the section above 

 Delevan, N. Y. Except for a short section near the source and one 

 large pool containing a spring, the stream Avas found unfit for 

 brook or brown trout by reason of the high Avater temperatures. If 

 a normal stocking were made in a stream like this, it is believed 

 that an unnecessarily large proportion of the fish would disappear 

 which would mean a waste of valuable stock. 



It is therefore recommended in sucli a case that small yearly 

 ])lantings be made, a number just sufficient for local angling needs 

 with the ex])ectation that nearly all will have been caught before 

 they are old enough to migrate. It must be understood that under 

 these conditions that natural spawning would play no part in 

 maintaining the supply and annual plantings would ahvays be 

 necessary. In the present survej^ Ave have indicated plantings of 

 from one-eiglith to one-tenth of the normal number for several 

 streams of this character. 



Competition Between Minnows and Trout. — Many species 

 of brook minnows consume lo a gi-eater or lesser degree the same 



