Hannaea p 



1032 Twelfth Avenue • Helena. MT 59601 • (406) 443-2196 



e-mail: lbahls(asel way.unrt.edu ^ 



March 21, 2000 



Ms. Carol Endicott 



Monitoring and Data Management Bureau 



Montana Department of Environmental Quality 



P.O. Box 2 09 01 



Helena, Montana 59620-0901 



Re: Box Elder Creek and Musselshell River Periphyton Reports 

 DEQ Contract No. 200012 



Carol , 



Enclosed are my reports on Box Elder Creek and the Musselshell 

 River, based on samples submitted by the Riparian and Wetland 

 Research Program of The University of Montana. I talked to Amy 

 Chadwick and she said that these were separate studies, so I did 

 a separate report on each one. 



These projects were very instructive. Box Elder Creek is an 

 intermittent stream and the samples were collected only from pool 

 edges. The periphyton indicated that all of the sites were 

 moderately impaired, most frequently by siltation. Among the M 

 impaired sites was the upstream reference site- -the only site 

 where riparian habitat was in decent shape. The Musselshell 

 River is a perennial stream and the samples were collected only 

 from rocks in riffles. The periphyton indicated that all of the 

 sites fully supported their aquatic life uses, whereas riparian 

 habitat was rated as partly at risk at all sites due to sparse 

 vegetation and exotic species. 



From all of this I would conclude the following: (1) periphyton 

 metrics are relatively insensitive to riparian condition (unless 

 riparian condition has a measurable effect on water quality) ; (2) 

 excessive sedimentation in perennial, high energy prairie streams 



(e.g., the Musselshell River) can be detected only by gathering a 

 composite, multi-habitat sample from riffles, runs, and pools 



(per MDEQ SOPs) ; and (3) separate sets of biocriteria may need to 

 be developed for perennial vs. intermittent prairie streams. 



Sincerely, 



Loren L. Bahls, Ph.D. ^ 



Phycologist 





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