Table 6. Percent abundance of major diatom species^ and values 

 of selected diatom association metrics for periphyton samples 

 collected from Cottonwood Creek on 8/21/01. Underlined values 

 indicate good biological integrity, minor impairment, and full 

 support of aquatic life uses,- all other values indicate 

 excellent biological integrity, no impairment, and full 

 support of aquatic life uses when compared to criteria for 

 prairie streams in Table 3 . 



Species/Metric 

 (Autecology) ^ 



Percent Abundance/Metric Values 

 M22CTWDC01 M22CTWDC02 M22CTWDC03 



Achnanthidium minutissimum (tol) 

 Cocconeis pediculus (eu) 

 Cymbella af finis (eu) 

 Encyonopsis microcephala (tol) 

 Epithemia sorex (eu) 

 Gomphonema parvulum (tol) 

 Navicula capitatoradiata (eu) 

 Navicula cryptotenella (tol) 

 Nitzschia frustulum (eu) 

 Nitzschia palea (eu) 

 Nitzschia paleacea (eu) 

 Synedra ulna (eu) 

 Cells Counted 

 Total Species 

 Species Counted 

 Species Diversity 

 Percent Dominant Species 

 Disturbance Index 

 Pollution Index 

 Siltation Index 

 Percent Abnormal Cells 

 Percent Epithemiaceae 

 Similarity Index^ 



^ A major diatom species is one that accounts for 3% or more of 

 the cells in one or more samples of a sample set 



^ Autecology 



eu: best growth in stronger mesotrophic to eutrophic waters 



tol: tolerant of a wide range of trophic status from oligo- 

 to eutrophic waters without discernible preference 



' The percent community similarity between CTWDC 01 and CTWDC 03 

 was 38.04%. 



