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<br />with patches of filimentous algae ($pirogjra sp.) in the channel <br />(Figure 3). Station 2 on Middle Creek was similar, but also had <br />pockets of Scirnus sp, and a peripheral growths of Beckmannia <br />sp, at the lower end of the section (Figure 4). Middle Creek <br />Station 3 had no instream macrophyte growth but had large stretches <br />of shoreline covered with Scirous sp., Carex sp., Eleocharis <br />sp., and ,wig sp. (Figure 5). <br />Both stations on Fish Creek contained instream patches of <br />filimentous algae and Potomageton sp. (Figures G and 7). <br />Shoreline species included Eleocharis sp., Carex sp., Juncus <br />sp., Ranunculus sp., and Equisetum sp. <br />The benthic invertebrates of the study area streams are <br />dominated by immature aquatic insects with crayfish, leeches, <br />segmented worms, and snails also common inhabitants. The abundance <br />of these organisms is related seasonally to the quantity of <br />streamflow. Peak densities are typically attained during <br />mid-summer when water is still abundant but flows are dropping. <br />Benthos diversity is related to both the quality of the water <br />• and the number of different microhabitats formed by the substrate <br />materials. A cobble substrate in a riffle environment is typically <br />~- the most productive type of stream habitat in terms of both <br />diversity and density (Haynes, 1970). <br />The general health of the benthic invertebrate community <br />is generally evaluated by examining the number of taxa present <br />and the calculated species diversity (D). The Shannon-Weiner <br />diversity index produces a value of less than 1 in areas of heavy <br />pollution or stress. Values from 1 to 3 indicate moderate stress <br />or pollution, and values exceeding 3 appear in clean water <br />situations or very healthy, diverse aquatic communities (weber, <br />1973) . <br />The highest number of organisms were collected from the <br />Station 1 beaver pond. Chironomids, leeches, and clams were <br />most numerous (Table 1). A comparison of density, taxa, and <br />diversity between the 1980 and 1981 sampling show no notable <br />changes (Table 2). The low diversity of this station is typical <br />of a lenthic environment. <br />Both the pool and riffle habitats of Station 2 had <br />approximately four times the number of organisms reported during <br />1980 (Table 2). This appears to result from the presence of large <br />7 <br />