Report: “Nutrients in the German Wadden Sea and the German Bay”#locale-eng:Report: “Nutrients in the German Wadden Sea and German Bight”
Description
The nutrient inputs across the rivers show a decreasing tendency despite large interannual differences. Outflow-standardised entries have been steadily decreasing since the mid-1980s at a rate of 2 to 3 % per year. For trend studies, nutrient concentrations in winter are best suited due to low biological activity. For phosphate and dissolved inorganic nitrogen (DIN), there is a significant decrease in winter for both the open German Bay and the Wadden Sea. The winter nutrient concentrations in the German Bay and the Wadden Sea, which are standardised to the salinity content 30, correlate significantly with the drain standardised river freights. The phosphate concentrations in the Wadden Sea and in coastal waters, which were standardised to the salinity content 30, were 1.06 ± 0.05 µmol/L (32.8 ± 1.5µg/L P) still above the reference value of 0.6 µmol/L (18.6 µg/L P) within the framework of the BLMP for coastal waters and the Wadden Sea. At 44.7 ± 3.2 µmol/L (0.63 ± 0.05 mg/L N), the concentrations of dissolved inorganic nitrogen normalised to the salinity 30 were three times higher than the orientation values of 11 to 14 µmol/L (0.15 to 0.20 mg/L N).#locale-eng:Riverine nutrient inputs have shown a declining trend, despite large interannual differences. Since the mid-1980s, flow-normalised inputs have decreased steadily at a rate of 2-3 % per year. Winter is best suited for trend analyses of nutrient concentrations because biological activity in this season is low. Levels of phosphate and dissolved inorganic nitrogen (DIN) decrease significantly in winter, both in the open German Bight and in the Wadden Sea. Nutrient concentrations in the German Bight and Wadden Sea in winter, normalised to salinity 30, correlate significantly with flow-normalised riverine loads. In 2006, phosphate levels normalised to salinity 30 reached 1.06 ± 0.05 µmol/L (32.8 ± 1.5µg/L P) in the Wadden Sea and coastal waters, exceeding the elevated level of 0.6 µmol/L (18.6 µg/L P) set by BLMP for these waters. Concentrations of dissolved inorganic nitrogen normalised to salinity 30, at 44.7 ± 3.2 µmol/L (0.63 ± 0.05 mg/L N), in 2006 still were three times higher than the elevated levels of 11.14 µmol/L (0.15 to 0.20 mg/L N).
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Tags
- bewirtschaftungsgebiete-schutzgebiete-geregelte-gebiete-und-berichterstattungseinheiten
- wrrl
- gdi-sh
- küstengewässer
- mdi-sh
- nutrients
- llur
- german-wadden-sea
- german-bight
- nährstoffe
- mdi-de
- umweltüberwachung
- nordsee