The winter distribution of nutrients in the Southern Bight of the North Sea (1961-1978) and in the estuaries of the Scheldt and the Rhine/Meuse
Van Bennekom, A.J.; Wetsteijn, F.J. (1990). The winter distribution of nutrients in the Southern Bight of the North Sea (1961-1978) and in the estuaries of the Scheldt and the Rhine/Meuse. Neth. J. Sea Res. 25(1-2): 75-87. https://dx.doi.org/10.1016/0077-7579(90)90010-E
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, meer
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| Trefwoorden |
Marien/Kust; Brak water; Zoet water |
| Auteurs | | Top |
- Van Bennekom, A.J., meer
- Wetsteijn, F.J.
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| Abstract |
In many years the winter distribution of nutrients in the eastern part of the Southern Bight is influenced by phytoplankton growth, always in February, sometimes in January but not in January 1961 and 1978, months with a relatively low insolation and high wind strength. The Scheldt river has higher nutrient concentrations than the rivers Rhine and Seine. The waters of the Scheldt river plume are distinguished from those of the Seine and the Rhine/Meuse with dissolved silica as a tracer. The extension of the Scheldt river plume is related to wind direction. The increase of inorganic nutrients from January 1961 to January 1978 in the northern part of the Southern Bight is related to the increase in the river Rhine. The increase in the Strait of Dover is related to discharges from the river Seine and the English coast. Only data outside the Scheldt river plume were selected for the comparison. An increase of nutrient concentrations is measurable over the entire salinity range and is largest for phosphate (up to 3 times at low salinities), less for nitrate (about 1.5 times for all salinities) and hardly noticeable for silicic acid. Nitrate extrapolation to low salinity agrees with upstream river values, but phosphate extrapolation gives higher concentrations, probably due to discharges of phosphogypsum in estuaries. |
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