51 



100 



80' 



60* 



40* 



20 



.82 



100 200 300 400 



MEAN FLOW (CFS) N0NI R RIGAT ION 



500 



FIGURE 12. Relationship between the annual rates of population decrease 

 of age III and older rainbow trout and mean nonirrigation 

 flows (cfs) in the Hildreth Section of the Beaverhead River. 



(%) 



a/ Indicates significance at 5% level 



