Long‐term change in dissolved inorganic nutrients in the heterotrophic Scheldt estuary (Belgium, The Netherlands)

We investigated long‐term trends (1965–2002) in dissolved inorganic nutrients in the tidal part of the Scheldt estuary (Belgium, The Netherlands). Annually averaged concentrations of dissolved silicate (DSi), dissolved inorganic nitrogen (DIN), and phosphate (DIP) increased significantly until the mid‐1970s, after which they declined linearly at rates of 0.6, 2.9, and 0.3 µmol L ‐ yr ‐ , respectively. This co‐occurred with a deterioration followed by a restoration of water column oxic conditions. Because of the differences in the reduction rate of DSi (1.2% yr ‐ ), DIN (1.7% yr ‐ ), and DIP (5... Mehr ...