of brook trout were, in approximate order of abundance, sucker fry, 

 adult longnose dace, and YOY mountain whitefish. Though brook trout 

 predation on grayling fry has been documented (Nelson 1954), it was 

 not seen in any of the samples collected in this study. The stomach 

 pumping portion of this study began when the YOY grayling were 

 approximately 2.5 inches long, which may be beyond the size that would 

 be consumed, though many of the dace and whitefish were larger than 

 this. 



Movements of Young-of-the-Year Arctic Grayling 



The 'spawning flags' placed in locations where MDFWP personnel 

 captured spawning grayling during the Spring of 1989 were often close 

 to the areas where large concentrations of YOY grayling were found. 

 Spawning typically took place on "riffle areas with clean surface 

 gravel which appeared 'bright' near pool or run habitats" (Shepard and 

 Oswald 1989) . The flags that marked these areas were often on riffles 

 immediately upstream or downstream of the capture sites (which were 

 often in pool or run habitats) , thus it seems likely that grayling 

 reared in an area stay in that area through at least their first 

 summer. Work by Kaya (1989) showed that Big Hole River Arctic 

 grayling fry exhibited the greatest tendency to remain stationary 

 (maintain their position with respect to linear flow) in an artificial 

 stream current of four populations he examined. 



Twenty-nine YOY grayling were marked in one area (in section G) 

 of which 11 were later recaptured. Nine of these were recaptured in 

 the same general area about three weeks later and two were recaptured 

 approximately 100 feet upstream three days after initial capture. 

 This supports the idea that these fish are loyal to a given area 

 (which may be as large as one riffle-pool-riffle complex) . Direct 

 observation suggests there may have been some daily movement among the 

 YOY grayling within an area. It appeared that the fish would remain 

 in or near aquatic vegetation in pool or run areas until about 1000 

 MDT (when water temperature reached about 59 F) when they would move 

 upstream closer to riffles to begin surface-feeding on small mayfly 

 spinners. This daily type of movement was supported, though not 



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