Adsorption and Sedimentation of Phosphorus by Clay Soils in Lake Lanier
Mayhew, Edmond A.
Mayhew, Mary C.
MetadataShow full item record
Total phosphorus (JP) has traditionally been the nutrient of choice for assessing the trophic status of lakes and has been used successfully throughout Canada and the upper United States. However, in Lake Lanier and in many other southeastern lakes phosphorus has not been a good determinant of trophic state. In these lakes high phosphorus loading in tributaries has not resulted in high productivity (Rast and Lee, 1978; Mayhew and Mayhew, 1992). Reckhow (1988) proposed that productivity is low in these lakes because clay is removing phosphorus and organics from the water column. The organics cause hypolimnetic oxygen deficits characteristic of eutrophy although the trophic state index for TP is oligotrophic or mesotrophic. Lake Lanier has the characteristic oxygen deficit and contradictory low TP of this type of lake (Mayhew and Mayhew,1991). The purpose of this study is to determine whether clays in the watershed adsorb and remove P from the water column of Lake Lanier. If this is the case, the high concentrations of P supplied by the rivers do not reach the euphotic zone and cannot contribute to lake productivity. However, organics also precipitated by the clay deplete dissolved oxygen in the hypolimnion.