TABLE 7. Percentage composition of benthos from the Yellowstone River using 



Hater's samples, November 1975. 



TABLE 8. Mean percentage composition of benthos from the Yellowstone River 

 using Water's samples, August-November 1975. 



SPECIES DIVERSITY 



Species diversity indices were calculated from Water's samples taken 

 during August-November 1975 in order to begin a monitoring study of the 

 Yellowstone River. Mathematical indices are one way of condensing long 

 species lists to a single mathematical value that can be compared with those 

 from other stations and other time periods. Four diversity indices, based on 

 data collected for this study and presented in raw form in Newell 1976, are 

 graphed and presented in figures 38-41. 



The Shannon-Weaver index (d), apparently the most sensitive to community 

 changes, is presented in figure 42. The Miles City and Sidney stations 

 exhibited the greatest seasonal change. The Glendive and Intake stations 

 were constant and similar (tables 9-12). 



59 



