NUTRIENT DISTRIBUTIONS IN THE SURFACE SEDIMENT OF THE CENTRAL LAGOON OF VENICE

Concentrations of nutrients in the sediments of the central lagoon of Venice were measured on a dry weight and volumetric basis and related to the biological activity (macroalgal biomass, shell fragments) of th e sampling sites. Different aspects of the lagoon eutrophication were monitored and the areas more affected by hypertrophic-dystrophic risk were identified. Sediment density and the high macroalgal standing cro p are the main factors responsible for the different nutrient distribu tions in the surface sediments. By comparing these data with others co llected in the past, a decreasing trend in nutrient concentrations was observed.