Eutrophication, caused by increased nutrient loadings, is one of the
factors influencing the quality of the Wadden Sea area. Since the
earliest nutrient measurements in the Wadden Sea, a clear increase
in nutrient loadings and concentrations has been documented. Among
the negative effects associated with the increased nutrient loads
are Phaeocystis-blooms, a decline in seagrass, increased
blooms of green macroalgae and anoxic sediments. After a peak in the
1980s nutrient levels have decreased again.
Eutrophication of the Wadden Sea continues to decrease. A main
development since the QSR 2004 is a continuation of the decrease of
riverine nutrient input. Also, compared to background estimates of
autumn NH4+NO2 concentrations, present values
are still clearly elevated but have decreased when compared to the
QSR 2004.
