Quality Assurance 



Several steps were taken to assure that the study results are accurate and reproducible. 

 Upon receipt of the samples, station and sample attribute data were recorded in the Montana 

 Diatom Database and the samples were assigned a unique number, e.g., 2653-01 . The first part 

 of this number (2653) designates the sampling site (Beaver Creek below Hilgard Creek) and the 

 second part (01) designates the number of periphyton samples that that have been collected at 

 this site for which data have been entered into the Montana Diatom Database. 



Sample observations and analyses of soft (non-diatom) algae were recorded in a lab 

 notebook along with information on the sample label. A portion of the raw sample was used to 

 make duplicate diatom slides. The slide used for the diatom proportional count will be 

 deposited in the Montana Diatom Collection at the University of Montana Herbarium in 

 Missoula. The duplicate slide will be retained by Hannaea in Helena. Diatom proportional 

 counts have been entered into the Montana Diatom Database. 



Results and Discussion 



Results are presented in Tables 3, 4 and 5, which are located near the end of this report 

 following the references section. Copies of aquatic plant field sheets are included in Appendix 

 A. Appendix B contains a diatom report for each sample. Each diatom report includes an 

 alphabetical list of diatom species in that sample and their percent abundances, and values for 65 

 different diatom metrics and ecological attributes. 



Sample Notes 



Beaver Creek below Hilgard Creek. This sample consisted of a 50 ml centrifuge tube 

 packed with Hydrurus foetidus and mud. The sample was extremely silty. 



Beaver Creek at Highway 287. This sample was sparse and consisted mostly of a small 

 wad of terrestrial plant roots. 



