Table 5. 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; bold values indicate fair 

 biological integrity, moderate impairment, and partial 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 mountain 

 streams in Table 2 . 



Species/Metric Percent Abundance/Metric Values 



(Autecology)^ M22CTWDC01 M22CTWDC02 M22CTWDC03 



Achnanthidiuin minutissimum (tol] 

 Cocconeis pediculas (eu) 

 Cymbella af finis (eu) 

 Encyonopsis microcephala (tol) 

 Epithemia sorex (eu) 

 Gowphonewa parvulum (tol) 

 Navicula capita toradiata (eu) 

 Navicula cryptotenella (tol) 

 Nitzschia frustulum (eu) 

 Nitzschia palea (eu) 

 Nitzschia paleacea (eu) 

 Symedra 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%. 



