On completion of the project, station information, sample 

 information, and diatom proportional count data will be entered 

 into the Montana Diatom Database. 



RESULTS AND DISCUSSION 



Results are presented in Tables 3 and 4, which are located 

 near the end of this report following the Literature Cited 

 section. Spreadsheets contajning completed diatom proportional 

 counts, with species' pollution tolerance classes (PTC) and 

 percent abundances, are attached as Appendix A. 



SAMPLE NOTES 



Cells at the tips of the Cladophora filaments in this sample 

 were often empty. The Cladophora filaments supported an 

 abundance of epiphytes, primarily diatoms in the genera Cocconeis 

 and Diatoma. Hannaea arcus was abundant in this sample. 



NON- DIATOM ALGAE 



The periphyton sample from Mol Heron Creek was dominated by 

 the filamentous green alga Cladophora, with diatoms ranking 

 second in biovolume and Ulothrix, another filamentous green alga, 

 ranking third (Table 3) . However, only small patches of green 

 filamentous algae were present in Mol Heron Creek and the amount 

 of filamentous green algae in the sample probably overestimates 

 the amount in Mol Heron Creek relative to other algae (Patrick 

 Newby, MDEQ, personal communication) . Cyanobacteria were less 

 important in Mol Heron Creek, with three genera- -Phormidi u/n, 

 Oscillatoria, and Anajbaena- -ranking 4th, 6th, and 7th in 

 biovolume, respectively. 



Cladophora is a common and widespread genus and often 



6 



