GRAYLING SPAWNING REPORT 



SPAWNING SITE CHARACTERIZATION 



Sites where ripe grayling were captured were visually 

 characterxzed including habitat type (rxffle, pool, etc.), 

 substrate type (size category ranked into one or more of the 

 following size classes: silt, sand, qrs.vei , cobble, or boulder), 

 and channel type (main channel, side channel, braided channel). 

 In addition, ten strearr.bed samples were taken from one known 

 grayling spawning site in the Big Hole River and a similar 

 habitat type unused by spawning grayling in the North Fork of the 

 Big Hole River with a hollow-core sampler (modified from McNeil 

 and Ahnell 1964). These core samples were oven dried and sieved 

 through 2.0, 1.0, 0.5, 0.37, 0.25, 0.09, 0.03, and 0.003 inch 

 mesh sieves and the material retained on each sieve was weighed 

 to the nearest 0.01 pound. Material left suspended in the water 

 during sampling was estimated according co methods presented in 

 Shepard et al. (1984). The percentage of each size class of 

 material was calculated for each core and averaged by site. 



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