results of this histological rating were presented as mean grade infection. Mean grade 

 infections above 2.7 are likely to result in population level declines (Vincent 2000). 

 Each sentinel cage also had an accompanying thermograph to establish mean daily water 

 temperatures during the exposure period. 



WSCT Genetic Investigations 



In 2004 and 2005, we tested Oncorhynchus genetic composition in WSCT habitat 

 in seven waterbodies (Appendix I). Samples consisted of non-lethal tissue samples (fin- 

 clip) taken fi-om a minimum 25 individual fish when possible. Samples collected were 

 immediately preserved in 95% ethyl alcohol and taken to the University of Montana, 

 Conservation Genetics Laboratory for analysis. The Paired Interspersed Nuclear DNA 

 Element-PCR (PINE-PCR) method is used to determine each fish's genetic characteristics 

 at 21 regions of nuclear DNA. This method produces DNA fi-agments (PINE markers 

 hereafter) that distinguish WSCT, fi-om rainbow trout and Yellowstone cutthroat trout. 

 These species specific PINE markers, therefore, can be used to determine whether a 

 sample came fi-om a suspected genetically pure population of one of these fishes or one in 

 which hybridization between two or all three of them has occurred. With a sample size 

 of 25 fish, this tesfing method has a 95% chance of idenfifying as little as 1% 

 introgression. 



Stream Temperatures 



Water temperatures (° F) were recorded at 48 to 72 minute intervals using Hobo 

 temperature or tidbit data loggers. Data for each station are summarized with monthly 

 mean, maximum, minimum and standard deviation in Appendix H. All water 

 temperature data collected between 1994 and 2005 (92 sites with 180 individual data 

 bases) was also complied into a GIS (ArcView) layer. For some streams we compared 

 temperature differences using paired t-tests and results were considered significant at the 

 alpha < 0.05. 



Objectives of the temperature data collections were to: 1) continue long-term data 

 collections at established monitoring sites; 2) profile temperatures over the length of the 

 river; 3) identify and monitor thermal properties of tributaries entering the river; 4) 

 identify thermal regimes favorable and unfavorable for trout; 5) monitor temperature 

 triggers used in the Blackfoot Emergency Drought Plan; 6) monitor stream restoration 

 projects; and 7) establish winter baseline and influence of upwelling in bull trout 

 spawning area; 8) assess relationships of water temperature to movements of rainbow 

 trout; and 9) compile data for future studies. 



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