distribution tank have been acquired. New plans 

 soon to be carried out will control the water from a 

 large spring above the lower unit of the Lewistown 

 Hatchery. Use of the spring water during periods of 

 high water in Spring Creek will eliminate problems 

 caused by high turbidity. Recurring damage to the 

 river wall and water supply line at the Great Falls 

 Hatchery will be avoided by extending the wall and 

 filling further out into the river. Routine maintenance 

 work has been carried out by all of our state hatch- 

 eries. 



Brood Stock 



The use of domestic brood stock has played a 

 very important part in the Montana fish hatchery 

 program. Presently brood stock is located at the 

 Arlee, Libby, Emigrant and Big Timber fish hatch- 

 eries. The value of a good, proven egg supply cannot 

 be underestimated. For example, the Arlee Hatchery 

 now produces up to five million rainbow trout eggs 

 and may be developed further. With established 

 brood stocks, the hatchery system has a basis on 

 which it can determine the number of eggs and fish 

 available from year to year. With wild stock eggs 

 it is impossible to estimate production figures until 

 trapping and spawning operations have been com- 

 pleted. While the holding of brood slock may cut 

 production somewhat at that particular station, the 

 advantages of a dependable egg source far out- 

 weighs the disadvantages. 



Almost all eggs taken from wild stock ore ob- 

 tained from the Somers Hatchery. 



This I ' 2 Ion truck with stainless steel tanks and oxygen tanks can 

 carry over 1,000 lbs. of fish for long distances. 



Montana's first distribution truck, a converted 1920 Buick. could 

 haul 150 lbs. of fish for short hauls. 



Distribution 



One of the most important functions of the hatch- 

 ery system, obviously, is the distribution of fish once 

 they are raised. A fish that has been reared to the 

 proper size for stocking is of little value if it cannot 

 be planted in good condition in the waters for which 

 it was intended. The Montana Fish and Game De- 

 partment has kept abreast of all new developments 

 in fish distribution and has actually worked out dis- 

 tribution units that fulfill the requirements of the long 

 hauls necessary in a state as large as Montana. 



The use of oxygen in the water, with agitators to 

 remove the toxic gases that accumulate from meta- 

 bolic wastes, has made it possible to transport in one 

 unit 1,000 to 1,200 pounds of live fish across the 

 entire state with a minimum of mortality. 



Investigations 



The Montana Fish and Game Department, in co- 

 operation with research scientists. Dr. Melvin Dollar 

 and Dr. Max Katz of the University of Washington, 

 has carried out extensive nutritional studies and dis- 

 ease studies of trout. Through these studies the De- 

 partment will achieve a more effective feeding and 

 disease control program in trout. This work is closely 

 allied to experiments in the incorporation of a nitro- 

 furan compound, NF 180, into our fish food as a 

 disease control. 



These investigations may lead to the answers 

 that will help the hatchery system rear some of the 

 native Montana species of fish that, in many cases, 

 seem highly susceptible to diseases when propa- 

 gated at the hatchery. 



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