Nutrient distribution in the surface sediments 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 the 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 crop are the main factors responsible for the different nutrient distributions in the surface sediments. By comparing these data with others collected in the past, a decreasing trend in nutrient concentrations was observed.