Concentrations of dissolved nutrients stayed at low levels at Lido (Table 1), whereas loads were significantly
greater in the innermost areas.
The terrigenous origin of orthosilicates was evident at S. Giuliano and Palude
(means higher than 50 lM).
Total dissolved inorganic nitrogen (DIN, as sum of ammonium, nitrite and nitrate) showed peaks corresponding to the areas subjected to industrial, urban and agricultural wastes, DIN values being very high at Fusina, Marghera, S. Giulianoand Palude (Table 1).
The nitrate form always prevailed, with mean percentages varying between 60% (S. Giuliano) and 79% (Lido); ammonia ranged between 17% (Lido and Palude) and 35% (S. Giuliano).
Similarly, orthophosphates were higher in the industrial (Marghera) and urban (S. Giuliano) areas, where an absolute peak of 7.9 lM was measured; minima were observed at Lido and Palude.