ฃThe relative weight of nitrite and phosphate, both associated
with microbial decomposition in sediments and inorganic
absorption, establishes the biochemical component. Ammonium
concentrations may be affected by various biogeochemical and
biological processes, including uptake by phytoplankton, excretion
by zooplankton and bacterial remineralisation, since both of them
can be stimulated by high temperature conditions. The inverse
correlation between ammonium and temperature suggests that
increased ammonium is related to resuspension of sediments
caused by winds or the jet of springs flowing into the lagoon as
pulse events, especially during winter. High silicate concentrations
are related to freshwater inputs. In fact, the positive correlation of
ammonium, nitrite, oxidised nitrogen, phosphate, silicate and total
nitrogen in the second factor probably indicates the importance
of the freshwater inputs with their inorganic and organic load
(see Fig. 5).