compatible with the Montana Diatom Database, e.g., 0745-02. The 



first part of this number (0745) designates the sampling site 

 (Little Dry Creek at Highway 200) ; the second part of the number 

 (02) designates the number of periphyton periphyton samples that 



have been collected at this site to date for which data have been 



entered into the Montana Diatom Database . 



Sample observations and analyses of soft (non-diatom) algae 

 were recored in a lab notebook along with station and sample 

 information provided by MDEQ . A portion of the raw sample was 

 used to make duplicate diatom slides. A subcontractor (E. Weber 

 of PhycoLogic) selected one sample at random from the sample set 

 and performed a reanalysis of the soft algae and an independent 

 count of diatoms on the duplicate slide for that sample. The 

 reanalysis is a check on taxonomic accuracy and on the 

 reproducibility of the sample processing and analysis methods. 



Common algal taxa should be the same for the two analyses of 

 soft algae. The percent community similarity index (Whittaker 

 1952) calculated from the two diatom counts should exceed 75%. 

 Major diatom taxa (>10% relative abundance) should be identified 

 similarly by both analysts. Synonyms are acceptable. Counts 

 completed on the two duplicate slides, and the resulting metrics 

 and bioassessments , should both yield the same use support 

 category (full support, partial support, nonsupport) for the site 

 in question. 



On completion of the project, station information, sample 

 information, and diatom proportional count data will be entered 

 into the Montana Diatom Database. One set of diatom slides will 

 be deposited in the University of Montana Herbarium in Missoula. 

 The other set of slides will be retained by Hannaea in Helena. 



RESULTS AND DISCUSSION 



Results are presented in Tables 4 and 5, located near the 

 end of this report following the Literature Cited section. 

 Spreadsheets containing completed diatom proportional counts, 

 with species pollution tolerance classes (PTC) and calculated 

 percent abundances, are attached as Appendix A. Results of 

 quality assurance analyses are presented in Appendix B. 



SAMPLE OBSERVATIONS 



