During the summer of 1955 the water users and State Water Con- 

 servation Board cooperated with the Department to cut the flows in 

 Tongue River below the dam for a short period of time. During the 

 cut in water flow, 680 pounds of "Fish-Tox" were applied to the 

 river in "slugs." There was a large population of fish in the section 

 of the river worked. In order of abundance by numbers, the fish 

 present were as follows: bullhead, black crappie, sucker, yellow perch, 

 redhorse, carp, brown trout, golden shiner, longnose dace, rock bass, 

 and wallej'e pike. One walleye pike and forty brown trout were 

 observed. 



Following toxicant application in 1955, 500,000 walleye pike fry 

 were liberated in the rehabilitated area from the U. S. Fish and Wildlife 

 Service Fish Cultural Station, Miles City. 



Because of the extensiveness of the Tongue River drainage and 

 the large area of rough fish infection, no effort could be made at 

 completely removing rough fish. It is hoped that the walleye might 

 become firmly established through reducing competition. If this is not 

 succesful, new efforts will be considered to provide fishing in this area 

 through "summer fallowing" discussed under tlie Marias River project. 



Ai 



TEST STREAM STUDY 



During this bicnniiun a research i)r()ject was begun on Mint I reck 

 in Granite County to work on tlie i)rol)lcnis of survival, growth and 

 condition of catchable-size planted hatcluMv rainbow trout. A large 

 part of the Fisheries Division's funds each year arc expended to rear 

 and plant catchable-size trout. There is a great number of indications 

 and a great deal of information which jioints out that a large percenta'^e 

 of catchable-size hatchery trout do not reacli the creol or otherwise 

 contribute to fishing success. It is the purpose of tiiis project to 

 evaluate these matters under controlled stream conditions. Catchable- 

 size hatchery fish are costly to produce. .Any increase in survival to 

 the creel which can be made will liave tlic same effect as increased 

 hatchery production without addid cxpt'nditnres for this increased 

 production. 



— 60 



