The fate of biogenic iron during a ...
Document type :
Article dans une revue scientifique: Article original
Title :
The fate of biogenic iron during a phytoplankton bloom induced by natural fertilisation: Impact of copepod grazing
Author(s) :
Sarthou, Géraldine [Auteur correspondant]
Laboratoire des Sciences de l'Environnement Marin (LEMAR) [LEMAR]
Vincent, Dorothée [Auteur]
Université du Littoral Côte d'Opale [ULCO]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Christaki, Urania [Auteur]
Université du Littoral Côte d'Opale [ULCO]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Obernosterer, I. [Auteur]
Laboratoire d'océanographie biologique de Banyuls [LOBB]
Timmermans, Klaas [Auteur]
Royal Netherlands Institute for Sea Research [NIOZ]
Brussaard, Corina [Auteur]
Royal Netherlands Institute for Sea Research [NIOZ]
Laboratoire des Sciences de l'Environnement Marin (LEMAR) [LEMAR]
Vincent, Dorothée [Auteur]
Université du Littoral Côte d'Opale [ULCO]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Christaki, Urania [Auteur]

Université du Littoral Côte d'Opale [ULCO]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Obernosterer, I. [Auteur]
Laboratoire d'océanographie biologique de Banyuls [LOBB]
Timmermans, Klaas [Auteur]
Royal Netherlands Institute for Sea Research [NIOZ]
Brussaard, Corina [Auteur]
Royal Netherlands Institute for Sea Research [NIOZ]
Journal title :
Deep Sea Research Part II: Topical Studies in Oceanography
Pages :
734-751
Publisher :
Elsevier
Publication date :
2008-04-11
ISSN :
0967-0645
English keyword(s) :
Iron
regeneration
food web
copepod
grazing
phytoplankton bloom
regeneration
food web
copepod
grazing
phytoplankton bloom
HAL domain(s) :
Planète et Univers [physics]/Océan, Atmosphère
Planète et Univers [physics]/Sciences de la Terre/Océanographie
Planète et Univers [physics]/Sciences de la Terre/Océanographie
English abstract : [en]
The impact of copepod grazing on Fe regeneration was investigated in a naturally iron fertilised area during KEOPS (Kerguelen Ocean and Plateau compared Study, Jan.-Feb. 2005). 55Fe labelled natural plankton assemblages ...
Show more >The impact of copepod grazing on Fe regeneration was investigated in a naturally iron fertilised area during KEOPS (Kerguelen Ocean and Plateau compared Study, Jan.-Feb. 2005). 55Fe labelled natural plankton assemblages (< 200 μm) were offered as food to copepod predators sampled in the field (Calanus propinquus, Rhincalanus gigas, Metridia lucens and Oithona frigida). Diatoms (Eucampia antarctica, Corethron inerme and Navicula spp.) constituted the bulk of the protists whereas microzooplankton (i.e. ciliates and dinoflagellates) were in very low abundance. Copepod grazing on phytoplankton ranged from 0.3 to 2.6 µgC ind-1 d-1 and reflected low utilisation of the food stocks (1-10% of total Chlorophyll a d-1) and low daily rations (0.2-3.3 % body C d-1). Copepod grazing resulted in a 1.7-2.3-fold increase in Fe regeneration. Fe speciation determined by extraction onto C18 columns showed that less than 1% of the regenerated Fe was complexed with hydrophobic organic ligands. This suggests that Fe was regenerated as inorganic species and/or bound to freely soluble organic ligands. The biogenic Fe budget established from our study and literature based data indicates that most of the primary production is recycled through the detrital pool, which represents the largest Fe pool (49% of total Fe). Our iron budget further indicates that mesozooplankton and diatoms represent the dominant Fe biomasses above the Kerguelen plateau. The rate of Fe regeneration accounts for half of the Fe demand, strengthening the need for new Fe sources to sustain the massive phytoplankton bloom above the Kerguelen plateau.Show less >
Show more >The impact of copepod grazing on Fe regeneration was investigated in a naturally iron fertilised area during KEOPS (Kerguelen Ocean and Plateau compared Study, Jan.-Feb. 2005). 55Fe labelled natural plankton assemblages (< 200 μm) were offered as food to copepod predators sampled in the field (Calanus propinquus, Rhincalanus gigas, Metridia lucens and Oithona frigida). Diatoms (Eucampia antarctica, Corethron inerme and Navicula spp.) constituted the bulk of the protists whereas microzooplankton (i.e. ciliates and dinoflagellates) were in very low abundance. Copepod grazing on phytoplankton ranged from 0.3 to 2.6 µgC ind-1 d-1 and reflected low utilisation of the food stocks (1-10% of total Chlorophyll a d-1) and low daily rations (0.2-3.3 % body C d-1). Copepod grazing resulted in a 1.7-2.3-fold increase in Fe regeneration. Fe speciation determined by extraction onto C18 columns showed that less than 1% of the regenerated Fe was complexed with hydrophobic organic ligands. This suggests that Fe was regenerated as inorganic species and/or bound to freely soluble organic ligands. The biogenic Fe budget established from our study and literature based data indicates that most of the primary production is recycled through the detrital pool, which represents the largest Fe pool (49% of total Fe). Our iron budget further indicates that mesozooplankton and diatoms represent the dominant Fe biomasses above the Kerguelen plateau. The rate of Fe regeneration accounts for half of the Fe demand, strengthening the need for new Fe sources to sustain the massive phytoplankton bloom above the Kerguelen plateau.Show less >
Language :
Anglais
Peer reviewed article :
Oui
Audience :
Internationale
Popular science :
Non
Source :
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