2001. The upper site (Y04USR03) is located just below Daisy- 

 Creek (Map 1) . The lower site (Y04USR04) is located about a mile 

 and a half downstream just above the Wilderness boundary (Map 2) . 

 Coordinates of the sampling sites are as follows: 



Y04USR03 45 04 05 N/109 59 39 W 

 Y04USR04 45 05 32 N/109 59 34 W 



Land uses in the Stillwater River basin include wilderness, 

 hardrock mining, recreation, and wildlife. The Stillwater River 

 is classified B-l in the Montana Surface Water Quality Standards. 



METHODS 



Periphyton samples were collected by Patrick Newby (Water 

 Monitoring Section, MDEQ Monitoring and Data Management Bureau) 

 following standard operating procedures of the MDEQ Planning, 

 Prevention, and Assistance Division. 



Using appropriate tools, microalgae were scraped, brushed, 

 or sucked from natural substrates in proportion to the rank of 

 those substrates at the study site. Macroalgae were picked by 

 hand in proportion to their abundance at the site. All 

 collections of microalgae and macroalgae were pooled into a 

 common container and preserved with Lugol ' s solution. 



The samples were examined to estimate the relative abundance 

 and rank by biovolume of diatoms and genera of soft (non-diatom) 

 algae according to the method described by Bahls (1993) . Soft 

 algae were identified using Dillard (1999), Prescott (1978), 

 Smith (1950), and Whitford and Schumacher (1984). These books 

 also served as references on the ecology of the soft algae, along 

 with Palmer (1977) . 



