nomical management measures to use wherever 

 hatchery fish are involved. 



A lake stocking table was assembled on 

 the basis of published factual information on 

 trout survival and harvests and on the basis 

 of information and experience of fishery work- 

 ers in Montana. The table was accepted as 

 Department policy by the Commission. It will 

 assure that all lakes are managed according 

 to the best biological information available and 

 will also assure equitable distribution of hatch- 

 ery fish to deserving areas. 



The hatchery biologist assisted with a ten 

 day in-service training school for mountain 

 lake survey crews. The school was conducted 

 at Montana State College under the direct 

 supervision of Dr. C. J. D. Brown. Such crews 

 will work to obtain the biological information 

 needed in management of the back-country 

 sport fishery. 



A new bacterial disease of yellow perch 

 was discovered in Dailey Lake near Living- 

 ston, Montana. The disease does not affect 

 other fish species and this may explain why 

 perch have not overpopulated Dailey Lake. 

 Investigation of this disease will be continued 

 along with other studies of wild and hatchery 

 trout disease and nutrition. 



THE MONTANA FISH HATCHERY 

 SYSTEM 



Montana's modern fish hatchery system 

 plays a major role in the maintenance of sport 

 fishing throughout the state's vast water re 

 sources. In addition to augmenting wild num- 

 bers of fish, many new impoundments and 

 rehabilitated waters have been stocked and 

 ,i ■ producing sporl fi hing I !ontinued expan- 

 ion of hatche] j facilities, increased efJ Lciency 

 of operation, and employmenl of modern-day 

 techniques have made Montana's hatchery sys- 

 tem equal to thai of any other state. The 

 Commi ion fee] thai the Pishing public can 

 ed ty i ontinuing the pre en1 propa 

 on proj ram and directing the outpul to 

 those areas thai are mo le to fisher- 



During the pasl biennium, expanded facili 

 ties al the I iev i tow n I fatchei j were com 

 pleted and pul into operation. The thirty addi 



11 be ii '-'i pi ini.ii ii- in the 



production of the large numbers of small fish 

 required for restocking rehabilitated waters. 

 Also, where fish are needed in future man- 

 agement of trout waters throughout the State. 

 they can be economically supplied by the 

 Lew istown Hatchery. 



Improvements were also made at other 

 state fish hatcheries. New foundations were 

 completed and new windows installed in the 

 main hatchery building at Anaconda, i 

 lines for the water supplies at both Great 

 Falls and Libby were replaced. Dirt ponds 

 at Bluewater and Big Timber were converted 

 to concrete. 



The increase in hatchery operations has 

 been accompanied by additional hatchery ad- 

 ministrative problems. The appointment of a 

 Superintendent of Hatcheries has resulted in 

 improved supervision and more efficient opera- 

 tion of the hatchery system. 



State hatcheries have made considerable 

 progress in the use of dry pelleted fish foods. 

 Pelleted food provides a nearly complete trout 

 diet and can be obtained economically from 

 commercial manufacturers at desired specifica- 

 tions. The cost of the dry food is less than 

 that of meat products and the problem of 

 storage and refrigeration has been greatly re- 

 duced. The conversion factor (the number of 

 pounds of feed required to produce a pound 

 of fish i of the pellet diet is actually better 

 than that of a meat diet. 



Recently, ten new fish-transportation tanks 

 were purchased. These tanks feature new 

 developments in design an elliptical shape 

 which tends to reduce the area where fish 



can congregate and smother from lack of oxy- 

 gen, and a two-inch covering of styra-foam 



insulation to assure constant temperature con- 

 trol, thus eliminating the need for refrigeration 

 01 icing en route. 



The old, out moded system of water recir- 

 culation bj mean-, of casolme motor driven 

 pumps has been replaced by administering 

 i ii directlj into the water. Bottled oxj 

 gen is forced through a haul carbon rod four 

 inches in diameter Located in the fish tran 



tation lank. The carbon rod diffuses the OXJ 



gen into the water in small microscopic parti 

 cles. This oxygen system is much less subjecl 

 to mechanical failure than the old n ■ 

 driven pumps. 



34 



