MEPS 166:43-52 (1998)  -  doi:10.3354/meps166043

Effects of iron stress on chromatic adaptation by natural phytoplankton communities in the Southern Ocean

M. A. van Leeuwe*, K. R. Timmermans, H. J. Witte, G. W. Kraay, M. J. W. Veldhuis, H. J. W. de Baar

Netherlands Institute for Sea Research, PO Box 59, 1790 AB Den Burg, Texel, The Netherlands
*Present address: University of Groningen, Dept of Marine Biology, PO Box 14, 9750 AA Haren, The Netherlands. E-mail:

Effects of iron stress on chromatic adaptation were studied in natural phytoplankton communities collected in the Pacific region of the Southern Ocean. Iron enrichment experiments (48 to 72 h) were performed, incubating plankton communities under white, green and blue light respectively, with and without addition of 2 nM Fe. Pigment ratios were affected by iron addition only to a minor extent. The pigment composition as dictated by the light conditions was similar for both the iron-enriched and the unamended bottles. Upon iron addition, phytoplankton auto-fluorescence, as estimated by flow cytometry, decreased markedly, indicating iron stress of the endemic phytoplankton community. It was concluded that iron did not control chromatic adaptation via the pigment composition, but exerted a clear effect on the efficiency of electron transfer.

Iron · Chromatic adaptation · Antarctic phytoplankton

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