Comparison of Phosphorus Dynamics in Two Oklahoma Reservoirs and a Natural Lake Varying in Abiogenic Turbidity

Abstract

The rate of phosphate uptake, the immediate fate of phosphate, and the potential rate of release of phosphate from dissolved phosphorus compounds in epilimnia of two reservoirs and one natural lake in northcentral Oklahoma were compared in the summer and in the late autumn. Sangre Isle Lake is a highly productive eutrophic impoundment, Sanborn Lake is a natural lake with low phytoplanktonic productivity, and Boomer Lake is an impoundment with modest productivity that is heavily affected by clay suspensoids. Although the uptake of phosphate (radiometrically determined) was rapid in each of these lakes in summer, the fate of phosphate in Boomer Lake differed from that of the others, with much of the phosphate sorbing to suspended silts and clays rather than biota (determined by isopycnic sedimentation). Recycling of phosphate from phosphomonoesters was greatest in Sangre Isle Lake, moderate in Sanborn Lake, but was undetectable in Boomer Lake. These findings suggest that high concentrations of clay suspensoids influence the epilimnetic P dynamics in reservoirs and lakes.