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. Giuliano
and 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