Sediment characteristics of the East Bay of Lake Lácar affected by sewage discharge

Several physical and chemical parameters of water column are used to determine the trophic status of aquatic environments. However, these parameters show strong seasonal fluctuations that might hinder the trophic classification of a water body. The determination of the chemical components of sediments, supplemented with P fractionation methods could provide a tool with predictive value of trophic status of aquatic environments. The aim of this study was to evaluate the effect of wastewater (phosphorus primarily) on the quality of the sediments of a Patagonian oligotrophic lake (Lake Lácar, San Martin de Los Andes, Neuquén, Argentina), and determine the influence on the distribution of P in relation to the elements that control its availability. The chemical results and fixation/release experiences of P performed indicate the existence of P release from the sediments into the water column, mainly in the central area of the bay, causing an internal load