DECLINE IN TOTAL PHOSPHORUS IN THE SURFACE WATERS OF LAKES DURING SUMMER STRATIFICATION, AND ITS RELATIONSHIP TO SIZE DISTRIBUTION OF PARTICLES AND SEDIMENTATION

The decline in total phosphorus (TP) in the surface waters of 40 oligo trophic to mesotrophic lakes during stratification varied from 0 to 59 .0%. Sediment traps were deployed in four of the lakes to examine the relationship between decline in TP and sedimentation. Declines in TP a nd sedimentation of P were similar in magnitude when summed over the s tratified season, and a positive correlation between TP decline and se dimentation rate was observed. Lakes possessing larger particles exhib ited larger declines in particulate phosphorus (PP) than lakes with sm aller plankton. Declines in TP were not significantly related to parti cle size, possibly because of the influence of spring concentrations o f dissolved P, which quickly declined in all lakes in which they were observed. These results support the contention that sedimentation play s a major role in the decline in TP during stratification and that sed imentation is influenced by plankton community structure.