ranked 3rd at this site. Ten genera of non-diatom algae were 

 recorded here, in four different divisions, including the red 

 alga Audouinella (Table 4). 



Poorman Creek. Diatoms dominated the periphyton community 

 in all three samples from Poorman Creek (Table 4) . Cyanobacteria 

 ranked second at the upper two sites: Nostoc at PoorC-Ol and 

 Phormidium at PoorC-02. These genera indicate cool waters with 

 relatively low levels of nutrients. The filamentous green alga 

 Spirogyra ranked second at PoorC-03. This alga, also known as 

 "pond scum", indicates warmer water temperatures, which may be 

 due to a large beaver dam complex just upstream (Michael Pipp, 

 MDEQ, pers . comm.) . 



The number of non-diatom genera was lower in Poorman Creek 

 than in the upper Blackfoot River: only 2 to 6 genera of non- 

 diatom algae were recorded at each site (Table 4) . This may be 

 due to the smaller size of Poorman Creek and natural stresses 

 associated with shading and cool waters of low mineral content . 

 Diatoms, green algae, and cyanobacteria were present at PoorC-01, 

 whereas only diatoms and cyanobacteria were present at PoorC-02. 

 Cyanobacteria were absent at the downstream site (PoorC-03), but 

 green algae and red algae were present here (Table 4) . 



Arastra Creek. On average, Arrastra Creek supported even 

 fewer non-diatom algae than did Poorman Creek (Table 5) . Only 

 diatoms and the cold-water chrysophyte Hydrurus foetidus were 

 found with regularity in the sample from AraC-01. Hydrurus 

 dominated the sample from AraC-02, followed by diatoms and the 

 filamentous green alga Ulothrix. These algae indicate cold 

 waters with relatively low levels of nutrients. 



Sandbar Creek. Diatoms dominated the periphyton sample 

 collected at SbrC-01 and the cyanobacterium Phormidium accounted 

 for the most biovolume at SbrC-02 (Table 5) . Among the non- 



