WSCT and bull trout from 2002 and 2003 were grouped by species to analyze 

 data in all cases excluding inter-annual differences. We compared the dates migrations 

 began for each species using a Kruskal-Wallis One Way Analysis of Variance on Ranks. 

 This test was also used to test for differences in the mean date WSCT entered tributaries, 

 and also to test if WSCT spent a significantly longer amount of time in the seven 

 tributaries used for spawning. Because of small sample size and failure to meet 

 parametric assumptions, we used Marm- Whitney Rank Sum test to determine if the mean 

 date bull trout entered tributaries to spawn were different, and if they stayed in a tributary 

 significantly longer than another. Mann-Whitney Rank Sum test was also used to 

 compare the mean dates migrations began for WSCT between years and if they entered 

 the tributaries at different times between the two study years. We used t-tests to 

 determine if migratory WSCT body lengths were different from non-migratory WSCT. 

 We used a simple linear regression to determine if there was a relationship between body 

 length and distance migrated and timing of migration. We also tested if the date 

 migration began was related to pre-spawning distance moved for WSCT and bull trout. 

 Simple linear regression was also used to test the relationship between spawning tributary 

 size (drainage area) and number of days WSCT spent in each of these tributaries. All 

 tests were performed at the alpha 0.05 level of significance. 



Results 



Of the 55 original radioed 

 fish, we successfully tracked 44 fish 

 (34 WSCT and 10 bull trout). The 

 remaining 11 WSCT either 1) fell 

 prey to avian predators (six heron and 

 one osprey). 2) were poached (n=2), 

 or 3) died due to survery-induced 

 mortality. Tracking began in March 

 2002 and confinued into March 2004. 

 We made 1882 contacts with an 

 average of thirty-seven contacts 

 (range: 16-83) for each fish. Of 44 

 telemetered WSCT, 42-two were 

 subspecifically pure based on DNA 

 analysis; two contained rainbow trout 

 genetic markers (Appendix M). 



Twenty-eight WSCT (Figure 

 48) trout and ten bull trout (Figure 49) 

 migrated during the two-year study 

 period. We found no significant size 

 differences between migrating and 

 non-migrating WSCT, and the mean 

 lengths for each group were within 

 0.2 inches (t-test, P = 0.5). The mean 

 starting date of migration for each 



Figure 47. Relationship of discharge (top) and temperattires 

 (bottom) to dates WSCT began migrations in 2002 and 2003. 



67 



