McNeil cores assessment of spawning substrates 



Spawning substrate analysis involved 33 McNeil substrate core samples from the 

 four spawning streams (Table 12). Summary statistics for major indices (percent fines 

 <6.35mm, Fredle indices, geometric mean and percent bull trout survival at emergence) 

 show a wide range of values for individual cores, but a very narrow range of mean values 

 among the four spawning areas. This narrow range includes the percentage of fine 



Grand mean 



29.6 



5.1 



12.6 



34.2 



Table 12. Summary of McNeil core sample results for four bull trout spawning areas 

 in the Blackfoot River watershed, 2004. 



sediment (<6.35mm - silt, sand and fine gravel) of ranging fi-om 28.5 to 30.7% and 

 geometric mean particles composed of medium-sized gravel ranging fi-om 11.4 to 13.2 



mm. 



Water Temperatures 



Temperature monitoring of the water column and substrate found a narrow range 

 of temperatures (Table 13). During the primary winter months (December, January and 

 February), Gold Creek recorded the coldest winter water temperatures of all sampled 

 streams, while Monture Creek recorded the highest average water column temperatures. 

 It was also the only tributary in which substrate temperatures were lower than column 

 temperatures, suggesting upwelling was occurring upstream rather than at the actual site 

 of the temperature sensor. A paired t-test analysis of grouped (all streams) mean water 

 column verses the substrate temperatures for the primary winter months (December, 

 January and February) found no relationship (P=0.367). 



Copper Creek 



Dunham Creek 



Month 



Water Column 



Substrate 



Water Column 



Substrate 



September 



Octot>er 



November 



December 



January 



February 



March 



43.8 ± 2,4 ( 40.2 - 48) 

 40.5 ± 2.6 (34.9 - 45.9) 

 36.8 ±2.1 (32.2-41.8) 

 35.3 ± 1 .8 (31 .2 - 39.7) 

 34.1 ±2.3(31.2-39.2) 

 34.5 ±1.7 (31.2 -38.1) 

 36.3 ±2.2 (31 ,7 -41 .3) 



44.5 ± 1 .6 (41 .6 

 41. 5 ±2.0 (37.1 • 

 37.9 ± 1 .6 (33.9 ■ 

 36.3± 1.4 (33.1 ■ 

 34.9 ± 1 .9 (32.5 • 

 35.4 ±1.1 (33.3- 

 37.0 ±1.5 (33.9- 



47.7) 

 45.5) 

 41.3) 

 39.0) 

 38.5) 

 37.6) 

 40.4) 



42.9 ± 1 .7 (40.5 - 

 40.4 ± 1 .9 (35.3 - 

 38.6 ± 0.8 (36.3 - 

 37.4 ± 1 .0 (35.3 - 

 35.9 ±1.3 (32.1 - 

 36.1 ±1.2(34.2 

 36.3 ± 1 .2 (34.2 - 



46.3) 



44.7) 



41.1) 



39.5) 



39.5) 



-40) 



40.6) 



43.9 ±1.7 (41.8 

 41.4± 1.8 (36.4 

 39.6 ± 0.8 937.5 

 38.5 ±1.0 (36.1 

 37 ± 1 .3 (33.2 - 

 37.1 ±1.2 (35- 

 37.3 ± 1 .2 (35.2 



- 47.4) 



- 45.7) 

 -42.1) 



- 40.7) 

 40.4) 

 40.7) 

 ■41.2) 



Gold Creek 



Monture Creek 



Table 13. Summay of water temperatures (mean, SD, range) for water column and substrate sites at four 

 bull trout spawning areas. 



73 



