Murray Creek. Diatom metrics indicate that Murray Creek had good biological 

 integrity and provided fiill support of aquatic life uses. Slightly elevated siltation index values 

 suggest minor impairment from sedimentation. Both sites also supported large numbers of 

 Planothidium spp., which are adapted to living attached to sand grains. A low pollution index 

 value at the lower site suggests minor impairment from organic loading. The two sites on 

 Murray Creek shared about half of their diatom assemblages. 



Douglas Creek. Diatom metrics indicate progressively increasing organic loading and 

 sedimentation in a downstream direction on Douglas Creek. The upper site was dominated by 

 Cymbella excisa, an eutraphentic species that favors elevated concentrations of inorganic 

 nutrients. The large percentage of this diatom resulted in the lowest diversity index (2.64) of all 

 the sites in the sample set. Otherwise, this site had normal metric values for a mountain stream. 

 The middle site was floristically much different from the upper site and was subject to minor 

 impairment from organic loading and sedimentation. The lower site was severely impaired by 

 sedimentation and suffered more serious but still minor impairment from organic loading. 



Gallagher Creek. Diatom metrics suggest minor impairment from organic loading and 

 sedimentation in Gallagher Creek. Otherwise, Gallagher Creek had normal metric values for a 

 mountain stream. 



Washington Creek. Diatom metrics suggest impairment from sedimentation at both 

 sites on Washington Creek. Impairment was moderate at the upper site and se\ere at the lower 

 site. Minor impairment from organic loading was indicated at both sites, which had identical 

 pollution index values. The two sites on Washington Creek shared 43% of their diatom 

 assemblages, which indicates a minor amount of environmental change. 



Jefferson Creek. Both sites were subject to minor impairment from sedimentation. In 

 addition, the lower site had minor impairment from organic loading. The dominant diatom 

 species at the upper site {Epithemia sorex) indicates eutrophic but nitrogen-limiting conditions. 

 The dominant species at the lower site {Melosira varians) indicates elevated concentrations of 



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