Table 4. Shannon-Weaver species diversity indices for bottom fauna collected in 1971, 

 1972 and 1975 at Pop's Place and Flesher stations. 



In analyzing whether significant differences in diversity indices occur between samples. Cairns 



(1967) states that "For biologically oriented readers, my own operational definition of optimal 



is the ability to support an aquatic community in a pattern which does not vary more than 20 

 percent from the empirically estimated maximum steady-state diversity possible in each 

 particular locale." Newell (1976b and Appendix D) interprets this to mean that variations of up 

 to 20% of maximum observed diversity can be called normal and healthy but deviations over 

 20% are called unhealthy. 



The highest diversity indices found for the pooled data at Pop's Place and Flesher for 1971 and 

 1972 were compared with the diversity indices at the two stations for 1975 (See Table 4). These 

 comparisons show a 62.2% deviation at Pop's Place and 27.6% deviation at Flesher, indicating a 

 signflcant difference in bottom fauna populations, particularly at Pop's Place, as a result of dam 

 failure. 



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