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classified into size categories of silt (<0. 00244 in), sand 

 (0.0024-0.0787 in), small gravel (0.0787-0.236 in), large gravel 

 (0.236-2.52 in), cobble (2.52-9.84 in), and boulder (>9.84 in). 

 Embeddedness was visually estimated by examining individual 

 cobble or large gravel particles for the level of the rock 

 stained by the substrate in which they were embedded. Percent 

 embeddedness was determined by dividing the distance from the 

 stain line to the bottom of the rock by the distance from the top 

 to the bottom of the rock. Cover was visually estimated, and 

 cover types were aquatic vegetation, terrestrial vegetation (no 

 higher than 1 foot above water surface) , submerged soil clumps 

 (products of sloughing banks), undercut banks, rocks, and 

 turbulence. Cover was only classified as such if it was deemed 

 to be usable by the fish. Intensive habitat measurements were 

 taken at each capture site, using a 3.28 ft^ (1 m^) cell centered 

 on the capture site. Water depth and velocity (mean and bottom) , 

 substrate, embeddedness, cover, cover type and distance to 

 nearest cover (including type of cover) were measured. 



In areas where only a few age 0+ fish were captured 

 ("non-intensive-use areas"), habitat measurements took one of two 

 forms: 1) measurements of water depth and velocity (mean and 

 bottom) , substrate, cover, cover type and distance to cover were 

 determined for a 3.28 ft area centered on the capture site; or 

 2) measurements were made along a single transect which ran 

 through the capture site and was oriented perpendicular to the 

 streamflow. Along this transect, measurements of depth and water 

 velocity were taken at 1.09 ft intervals, while estimates of 

 substrate, cover and cover type were made at 3.28 ft intervals 

 along the transect. Intensive measurements at the capture sites 

 were also taken in the 3.28 ft^ cell as described above. 



Water temperatures were measured with pocket thermometers 

 throughout the duration of the study. Thermometers had 1°F 

 markings, and temperatures were measured to the nearest 0.5°F. 

 Measurements were taken as time permitted, on an irregular basis, 

 with most of the measurements being taken from mid-morning to 

 early afternoon. 



All data recorded for evaluation of habitat utilization were 

 computerized for easier analysis using a Zenith 286 PC. Data 

 were entered into DBASE III+ software files modified for this 

 study. Data files were sorted and loaded into Statgraphics 

 software files for analysis. Measurements of habitat features 

 utilized by and available to YOY Arctic grayling were analyzed 

 according to the recommendations of Bovee (1986) . He suggested 

 plotting frequency histograms of each habitat variable, and 

 fitting a "utilization" or "availability" curve to the 

 histograms. The curves are based on the principle of 

 non-parametric tolerance limits, and are appropriate to use in 

 situations where data sets are small and distribution is not 



