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RESULTS AND DISCUSSION 



Distribution and abundance of fishes 



Age 0+ Arctic grayling were found in highest concentrations 

 in Swamp Creek, the west channel of the Big Hole River above and 

 below the bridge (including an associated irrigation ditch), and 

 the east channel below the bridge (sample sections D,E,G,H,J and 

 L) , while only one age 0+ fish was found in the upper sample 

 sections (A,B,C and I) (Table 2). Older Arctic grayling followed 

 this same pattern of occurrence, with three notable differences: 

 1) seven age 1+ grayling (6-9 inches) were found in Governor 

 Creek; 2) no older grayling were found in Swamp Creek; and 3) no 

 older grayling were found in the irrigation ditches. 



Several investigators have found Arctic grayling in other 

 areas of the upper Big Hole River drainage in recent years. 

 Liknes (1981), in his extensive survey of the upper drainage in 

 1978 and 1979, found age 0+ grayling ranging from Governor Creek 

 downstream to an area near the mouth of Fishtrap Creek. 

 Young-of-the-year fish were also found in an irrigation ditch off 

 the North Fork of the Big Hole River. Distribution of age I and 

 older fish in the main stem was restricted to the area between 

 Tom Clemow Lane and the Wisdom cemetery, but they were also found 

 in numerous tributaries, including the inlet and outlet of lakes 

 on Miner and Mussigbrod Creeks, respectively. In surveys 

 conducted since 1986, MDFWP personnel have found age I and older 

 grayling in numerous other tributaries to the Big Hole River, 

 including Fishtrap, LaMarche and Deep creeks and the Wise River 

 (Brad Shepard, pers. comm.). The fish in the Wise River were in 

 the mainstem and Wyman and O'Dell creeks, and likely drifted 

 downstream from lakes in the drainages. 



Young-of-the-year brook trout ( Salvelinus fontinalis ) were 

 plentiful in two of the upper sample sections (B and C) , the 

 tributaries (sample sections I, J and K) and the east channel of 

 the Big Hole River below the bridge (sample section H) . They 

 were scarce in all other sample sections around the Wisdom Bridge 

 (D,E,F and G) and absent in the irrigation ditches. Older brook 

 trout followed this same general pattern, except that older fish 

 were plentiful in sample section A. 



Rainbow trout ( Oncorhynchus mykiss ) were plentiful only in 

 the Dooling Bridge sample section (A) and in Governor Creek 

 (sample section I) . Only nine rainbow trout were found in lower 

 sample sections of the drainage, and may have drifted down from 

 upper portions of the drainage. 



Certain patterns of distribution were apparent for other 

 fishes captured in the Study Area (Table 3) . The occurrence of 

 mountain whitefish ( Prosopium williamsoni ) was quite variable, 

 and there were only three sample sections (B, C and G) where 



