Chemical limitations on phytoplankton growth in the Crozet Basin, Subantarctic Southern Ocean. - Université Pierre et Marie Curie Accéder directement au contenu
Article Dans Une Revue Deep Sea Research Année : 2002

Chemical limitations on phytoplankton growth in the Crozet Basin, Subantarctic Southern Ocean.

Résumé

To evaluate the sufficiency of ambient iron and nutrient levels for algal growth in surface waters of the Crozet Basin, in the Indian-Subantarctic region of the Southern Ocean, shipboard iron- and nutrient-addition bottle-incubation experiments were performed during the Antares-IV campaign in January-February 1999. The experiments were conducted with plankton collected from near-surface (~20 m depth) waters at three locations between 43-46°S and 61-65°E, each characterised by relatively low algal biomass (0.2-0.7 µg L-1 chlorophyll a) and dissolved iron concentrations (~0.1-0.3 nM): (1) the Polar Frontal Zone (~19 µM nitrate and 1.2 µM silicate), (2) the confluence of the Subantarctic and Subtropical Fronts (~5.4 µM nitrate and 0.5 µM silicate), and (3) the Subtropical Zone north of the Agulhas Front (< 0.1 µM nitrate and ~1.4 µM silicate). Our experimental results demonstrate three different regimes of chemical limitation on phytoplankton production and community structure within this small oceanic area: in the Polar Frontal Zone, primary limitation of community production by iron deficiency, and secondary limitation of diatom production by silicate deficiency; within the Subantarctic-Subtropical Frontal Zone, primary and secondary limitation of community production by deficiencies in iron and silicate, respectively; and within the southern Subtropical Zone, primary and secondary limitation of community production by deficiencies in nitrate/phosphate and iron, respectively.
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Dates et versions

hal-00480622 , version 1 (04-05-2010)

Identifiants

  • HAL Id : hal-00480622 , version 1

Citer

Peter Sedwick, Stéphane Blain, Bernard Queguiner, Brian Griffiths, Michel Fiala, et al.. Chemical limitations on phytoplankton growth in the Crozet Basin, Subantarctic Southern Ocean.. Deep Sea Research, 2002, 49 (16), pp.3327-3349. ⟨hal-00480622⟩
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