that they require inorganic nitrogen (nitrates and ammonia) as nutrients. These diatoms also 

 tolerate elevated levels of organic nitrogen in the water. The modal category for nitrogen uptake 

 at Eagle Creek site 3 was "not classified". 



Differences in moisture categories were noted between the 4 sites, which indicates the 

 degree to which the sites are dewatered (Table 5). The most persistent flows (and least 

 dewatering) were recorded at Eagle Creek site 2, where the modal category is of diatoms that are 

 rarely found outside water bodies. The site with the next most persistent flows was Eagle Creek 

 site 1, where most diatoms are typically found in water bodies and only sometimes on wet or 

 moist substrates. The largest fluctuations in streamflow were noted in Dog Creek and at Eagle 

 Creek site 3, where most diatoms are found mainly in waterbodies but also regularly on wet or 

 moist substrates. 



• 



References 



APHA. 1998. Standard Methods for the Examination of Water and Wastewater. 20 th Edition. American Public 

 Health Association, Washington, D.C. 



Bahls, L.L. 1979. Benthic diatom diversity as a measure of water quality. Proceedings of the Montana 

 Academy of Sciences 38:1-6. 



Bahls, L.L. 1993. Periphyton Bioassessment Methods for Montana Streams (revised). Montana Department of 

 Health and Environmental Sciences, Helena. 



Bahls, L.L., Bob Bukantis, and Steve Tralles. 1992. Benchmark Biology of Montana Reference Streams. Montana 

 Department of Health and Environmental Sciences, Helena. 



Barbour, M.T., J. Gerritsen, B.D. Snyder, and J.B. Stribling. 1999. Rapid Bioassessment Protocols for Use 

 In Streams and Wadeable Rivers: Periphyton, Benthic Macroinvertebrates and Fish. Second Edition. 

 EPA/84 l-B-99-002. U.S. Environmental Protection Agency, Office of Water, Washington, D.C. 



Beaver, Janet. 1981. Apparent Ecological Characteristics of Some Common Freshwater Diatoms. 

 Ontario Ministry of The Environment, Technical Support Section, Don Mills, Ontario. 



Johansen, J.R. 1999. Diatoms of Aerial Habitats. Chapter 12 in Stoermer, E.F., and J.P. Smol (eds.), The Diatoms: 

 Applications For the Environmental and Earth Sciences, Cambridge University Press, New York. 



John, D.M., B.A. Whitton, and A.J. Brook (eds.). 2002. The Freshwater Algal Flora of the British Isles: An 

 Identification Guide to Freshwater and Terrestrial Algae. Cambridge University 



Karr, J.R., and DR. Dudley. 1981. Ecological perspectives on water quality goals. Environmental Management 

 5:55-69. 



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