Robert J. Gilliom 1984 <p><span>Regression relationships were developed between summer mean total phosphorus (P) concentrations in near-surface water and both chlorophyll </span><i>a</i><span> concentrations and Secchi disc transparency for Puget Sound region lakes. Total P concentrations in the lakes studied ranged from 7 to 66 μ/L. The relationship between total P and chlorophyll </span><i>a</i><span>, based on data from 69 lakes, explained 57 percent of the variance in chlorophyll </span><i>a</i><span>. Predicted chlorophyll </span><i>a</i><span> concentrations and 95 percent confidence intervals ranged from 1 </span>⁺³_-0.5<span>μg/L for 7 μg/L P to about </span>⁺³⁵_-10<span>μ/L for 66 μ/L P. The relationship between total P and Secchi disc, based on data from 71 lakes, explained 53 percent of the variance in Secchi disc. Predicted Secchi disc transparencies and 95 percent confidence intervals ranged from 5.5 </span>^+5.5_-3.0<span> m for 7 μ/L P to 1.4 </span>^+1.5_-0.7<span> m for 66 μ/L P.</span></p> application/pdf 10.1111/j.1752-1688.1984.tb04726.x en American Water Resources Association Relationships between water quality and phosphorus concentrations for Puget Sound region lakes article