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beak <br />Analysis of variance procedures were used to examine differences <br />• among stations for chlorophyll a, dry weight organic matter (DWOM), and <br />total density. Significant differences among stations were found for <br />chlorophyll a (F(3,8) 11.82, p<0.05). Subsequent comparisons of individual <br />station averages (Table 4,0-6) using Tukey's HSD test showed that chlorophyll <br />a at Station F (72.46 mg/m2) was significantly greater (p<0.05) than at <br />Stations C, D, or E. DWOM and total periphyton density showed similar <br />patterns of differences with averages for both highest at tation F (Tables <br />4.0-2 through 4.0-5 and 4.0-7). Stations C, D, and E were generally similar. <br />Results of analyses of variance, however, showed that Station F was not <br />significantly different from the other stations (DWOM: F(3,8) = 1.26, <br />p>0.05; total density: F(3,8) = 1.42, p>0.05). <br />The levels of periphyton pigment and organic matter and periphyton <br />• densities indicate nutrient levels (particularly nitrogen and phosphorus) <br />were high in this stretch of the North Fork Gunnison River. The chemical <br />analyses of concurrently collected water samples supports this assessment. <br />Qualitative samples of periphyton were obtained from Muddy Creek. The <br />periphyton was dense on creek bottom substrates and was comprised primarily <br />of the diatoms Diatoms hiemale and Melosira varians, both of which are <br />indicative of eutrophic (enriched) conditions (Lowe 1974). It appears that <br />the enriched water of the stretch from Stations C through F results <br />primarily from the quality of the water released from the Paonia Reservoir. <br />Since no discharge from the mining operation was observed between Stations <br />E and F, there is no apparent reason for the observed high levels of pigment, <br />organic matter, and densities at Station F. <br />• <br />4 -8 <br />