Details

Autor(en) / Beteiligte

• Leote, Catarina
• Mulder, Lieke L.
• Philippart, Catharina J. M.
• Epping, Eric H. G.

Titel

Nutrients in the Western Wadden Sea: Freshwater Input Versus Internal Recycling

Ist Teil von

• Estuaries and coasts, 2016-01, Vol.39 (1), p.40-53

Ort / Verlag

New York: Springer Science+Business Media

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• At present, phosphorus (P) is seen as the main limiting nutrient for phytoplankton growth in the western Wadden Sea. Six cruises were performed for water sampling at selected stations covering a full tidal cycle for later determination of dissolved and particulate nutrient concentrations. The major P sources were identified on a seasonal basis, by comparing the contribution of freshwater discharge and sediment release, calculated in a previous study, to the concentrations in the water column. A close relationship was found between the pelagic concentrations of dissolved inorganic nutrients and chlorophyll a, with a concomitant decrease in nutrients and increase in chlorophyll. This was observed in early spring and was followed by a later increase in the nutrient concentrations in spring–summer. The low concentrations found for the freshwater and seawater end-members for this period ruled out their importance as nutrient sources, suggesting that this increase resulted mainly from internal recycling in the Wadden Sea. Even though P limitation was observed during most of the year, a potential seasonal change in the limiting nutrient, from P to silica, was observed. The comparison between P supply to the Wadden Sea by freshwater discharge and sediment release showed a much higher contribution of the latter, especially in April-November. To our knowledge, this is the first study clearly presenting internal recycling as the main nutrient source to the western Wadden Sea in spring-autumn, instead of freshwater discharge or the North Sea.