PARTICULATE PHOSPHORUS SEDIMENTATION AT THE RIVER INFLOW TO A LAKE

Sedimentation at the Krutynia River inflow to Lake Kujno was closely r elated to hydrological regime. The highest sedimentation rates, record ed in spring, decreased during summer by two orders of magnitude. Gran ulometric segregation of settling seston along the inflow zone was rel ated to differentiation of phoshorus content. Smaller particles were r icher in P, producing a gradient of increasing P concentrations in the settling material. A substantial loss of P from polyphosphate and var ious organic fractions was found after settlement of river suspensoids . Mechanisms of P losses are discussed and possibilities of P retentio n within the inflow zone are considered.