Turbidity, nutrients and phytoplankton primary production in the Oosterschelde (the Netherlands) before, during and after a large-scale coastal engineering project (1980-1990) : Structure and functioning of the pelagic system

Turbidity, nutrient concentrations and phytoplankton primary production were monitored in the Oosterschelde before, during and after the construction of a storm-surge barrier and two compartment dams. Flow velocities and suspended matter concentrations decreased severely, causing an increased transparency of the watercolumn. In the eastern and northern compartments, the previously pronounced seasonal variation disappeared. Reduction of the freshwater load and decreasing nutrient concentrations in the adjacent North Sea coastal waters resulted in lower nitrite+nitrate and silicate concentrations. Autumn phosphate concentrations remained at the same level as before the nutrient reduction (...)