Phosphorus flux in lake peipsi sensu stricto, eastern europe

Abstract

Phosphorus distribution in sediments and monitoring data from Lake Peipsi sensu stricto (s.s.) were used to elucidate the distribution of P fractions in the lithological and geochemical composition of the lake's sediments. The composition of P fractions in the sediment cores was rather constant in layers with porosity lower than 88%. The decay of biota during the compression and genesis of sediments leading to the liberation of P to interstitial water and its further diffusion along the concentration gradient towards the sediment-water surface are directed by environmental conditions. During phytoplankton blooms the release of P fractions from sediments may be as high as 875 tonnes of P in Lake Peipsi s.s. Calculations show that the average annual total P accumulation in Lake Peipsi s.s. is ca 270 mg m -2 y -1.