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January 26,2024 <br /> Don Peterson <br /> Page 9 of 21 <br /> Reference: Water Quality Assessment of Silver View Pond,Mounds View,MN <br /> proportion of organic matter in the sediments(28-55%). There was quite a bit of variability in rates between <br /> cores at each station. For each rate shown in Figure 3, two sediment cores were collected to achieve an <br /> average rate with a measure of variability (± 1 standard deviation of the mean). No phosphorus <br /> accumulated in one of the sediment cores for station 1, so that measure represents one single core instead <br /> of an average rate.All replicates for Stations 2 and 3 showed high variability in rates as well, which is <br /> common in lake and pond sediments. <br /> Silver View Pond <br /> ■Anoxic Conditions ■Oxic Conditions <br /> 7 <br /> m 6 <br /> 0 5 <br /> U, <br /> d <br /> mN 4 <br /> N <br /> o ;_ 3 <br /> a <br /> 2 <br /> a <br /> 0 <br /> 1 2 3 <br /> Sampling Station <br /> Figure 3 Phosphorus release rates under oxic and anoxic conditions in Silver View Pond <br /> Sediments were also analyzed for phosphorus fractionation to quantify the mobile and non-mobile pools of <br /> phosphorus(Figure 4). This data provides us with an understanding of the potential for continued flux of <br /> phosphorus from the sediments. The pool of phosphorus that is considered most likely to diffuse from the <br /> sediments based on its reactivity and capacity to mobilize is redox-sensitive phosphorus (redox-P). This <br /> includes the iron-bound phosphorus fraction and the pool that is considered loosely bound (meaning it has <br /> simple bonds that can be easily broken). The horizontal lines in Figure 4 represent the 25th, 50th (median), <br /> and 75th percentiles for redox-P in our Minnesota lake sediment chemistry database. Redox-P <br /> concentrations in Silver View Pond sediments were in the lower range of concentrations observed in our <br /> database of lake sediments. <br /> Design with community in mind <br />