Title :

The intra-annual variability of soft-bottom macrobenthos abundance patterns in the North Channel of the Seine estuary

Author(s) :

Desroy, Nicolas [Auteur]
Laboratoire Environnement Ressources de Bretagne Nord [LERBN]
Janson, Anne-Laure [Auteur]
Biologie des organismes marins et écosystèmes [BOME]
Denis, Lionel [Auteur]
Université de Lille
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]
Charrier, Gregory [Auteur]
Laboratoire des Sciences de l'Environnement Marin (LEMAR) [LEMAR]
Southwest Fisheries Science Center [SWFSC]
Lesourd, Sandric [Auteur]
Université du Littoral Côte d'Opale [ULCO]
Ecosystèmes littoraux et côtiers [ELICO]
Dauvin, Jean-Claude [Auteur]
Laboratoire d’Océanologie et de Géosciences (LOG) - UMR 8187 [LOG]

Journal title :

HYDROBIOLOGIA
Consequences of estuarine management on hydrodynamics and ecological functioning ECSA 38th Symposium – Rouen 2004 Co-organisation Seine-Aval Programme and ECSA

Pages :

173-188

Publisher :

Springer

Publication date :

2007-09

ISSN :

0018-8158

English keyword(s) :

Temporal variability
Bentho-pelagic coupling
Sediment
Abra alba community
Anthropogenic impacts
Port 2000

HAL domain(s) :

Planète et Univers [physics]/Interfaces continentales, environnement
Planète et Univers [physics]/Océan, Atmosphère

English abstract : [en]

Temporal and spatial variability of the Abra alba–Pectinaria koreni and Macoma balthica communities was examined in the northern part of the Seine estuary (North Channel) over different space and time scales in order to ...
Show more >Temporal and spatial variability of the Abra alba–Pectinaria koreni and Macoma balthica communities was examined in the northern part of the Seine estuary (North Channel) over different space and time scales in order to assess the role that the hydrologic regime and/or anthropogenic influences play in defining benthic communities over time. Sediment in the North Channel displayed strong spatial and temporal variability, sustained by intense sediment transport episodes. Total macrobenthic abundances ranged widely on the course of the year and there was no evidence of a seasonal signal for the density fluctuations, whatever the spatial scale considered. The bio-sedimentary dynamics can be divided into two periods: the first corresponds to the high flow rate period (January–May) during which fauna is influenced by fine silt/clay deposition, and the second to the low flow rate period (June–December) during which sandy deposits prevail. Despite the absence of significant correlations between sediment composition and abundance, episodes of sediment transport seem to be an important structuring mechanism in the Seine estuary. As a consequence, the faunal composition varied throughout the year. The winter and spring fauna, characterised by species living on muddy fine-sands or muds, were enriched during the summer and autumn by species living in clean fine sand, such as Donax vittatus, Nephtys cirrosa or Spio decoratus, mainly represented by adult individuals. Secondary settlement of drifters may explain the rapid structuration of assemblages a few days after the sandy deposits. Our results suggest the importance of the bentho-pelagic coupling, primarily induced by the sedimentary instability, on the macrobenthic fauna dynamics. The intra-annual variability of assemblages at the mouth of the Seine river and the silted situation of the North Channel might simply be the result of the silting up and alteration of the inner estuary, generated by several decades of man-made modifications and natural processes.Show less >

Language :

Anglais

Popular science :

Non

Collections :

• Laboratoire d'Océanologie et de Géosciences (LOG) - UMR 8187

Source :

Harvested from HAL