Assessment of growth rate limiting nutrients in the North Sea by the use of nutrient-uptake kinetics
Riegman, R.; Colijn, F.; Malschaert, J.F.P.; Kloosterhuis, H.T.; Cadée, G.C. (1990). Assessment of growth rate limiting nutrients in the North Sea by the use of nutrient-uptake kinetics. Neth. J. Sea Res. 26(1): 53-60
In: Netherlands Journal of Sea Research. Netherlands Institute for Sea Research (NIOZ): Groningen; Den Burg. ISSN 0077-7579; e-ISSN 1873-1406, more
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Authors | | Top |
- Riegman, R.
- Colijn, F., more
- Malschaert, J.F.P.
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- Kloosterhuis, H.T.
- Cadée, G.C., more
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Abstract |
In eutrophication studies it is important to estimate the impact of various macro-nutrients. Nutrient-uptake kinetics as a tool for identification of nutrient-limited growth was applied on field samples from the North Sea and the westernmost inlet of the Wadden Sea (Marsdiep). It was demonstrated that low concentrations of dissolved nutrient do not automatically imply that they are limiting the growth rate of natural phytoplankton. Subsurface samples (5 m) taken on the North Sea in July 1988 showed nutrient limitation at all stations. At greater depths nutrient limitation was less severe. N-limitation dominated. At some stations more than one nutrient was limiting the multi-species population. During spring 1989 the diatom bloom in the Marsdiep inlet (The Netherlands) became silicate- limited. At the end of the Phaeocystis bloom, N- limitation was severe whereas during the decay of the bloom the N-limitation disappeared. During this transient period high numbers of ciliates (up to 54·103 cells·dm-3) and tintinnids (17·103 cells·dm-3) were present. |
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