Spatial and temporal variability
of zooplankton populations in Arcachon bay
(bay of Biscay) during oyster breeding
Dorothée Vincent
11 ', Christophe Luczak (2) , Benoît Sautour
(1)
(1) Universïté de Bordeaux 1, laboratoire d’océanographie biologique,
UMR-CNRS-EPOC 5805, 2 rue du Pr Jolyet, 33120 Arcachon, France
(2) IUFM Nord/Pas-de-Calais. UPRES-A CNRS ELICO. station marine, BP 80,
62930 Wimereux, France
d.vincent@biocean.u-bordeaux.fr
Abstract
Spatial and temporal short-term variations of zooplankton populations
were studied during oyster breeding in the most inner part of Arcachon
bav. This environment is submitted both to oceanic (bay of Biscay) and
continental (Leyre) inputs and its continental marshes are intensively
exploited for oyster farming.
This study is a first attempt to describe the zooplanktonic environment
of oyster larvae. Correspondence analyses showed that the mesozooplankton composition resulted from the mixingof several communities
dominated by copepods throughout the studv (64.3 ± 3.5
0 /n of total
abundance). Appendicularians and polychete larvac were the two other
dominant taxa (14.8 ± 6.0
( /o and 7.15 ± 3.8"/o, respectively). Three distinct
communities were observed:
(i) an autochtonous community with essentially Acartia discaudata, Acartia grani and Isias clavipes. ;
(ii) an inner community characterized by Acartia bifilosa and Acartia tonsa;
(iii) a neritic assemblage characterized by Paracalanus parvus and Penilia
avirostris.
Spatial and temporal variations of the communities were closely linked to
variations of environmental factors (temperature, salinitv and hvdrologv)
and particularly to changes in weather conditions. A storm event during
mid-August had an effect on the hydrodynamics in the bay with subsequent changes in the zooplankton communitv structure. lliis event resulted in a large scattering of holo- and meroplanktonic organisms (and
among them bivalve larvae).
Introduction
4'he knowledge of coastal ecosystems requires the studv of ecological
processes as well as the investigation of community stmctures. Zooplankton is an important biological component in semi-enclosed littoral
systems since both its high biomass and production rates can enhance
334
of zooplankton populations in Arcachon bay
(bay of Biscay) during oyster breeding
Dorothée Vincent
11 ', Christophe Luczak (2) , Benoît Sautour
(1)
(1) Universïté de Bordeaux 1, laboratoire d’océanographie biologique,
UMR-CNRS-EPOC 5805, 2 rue du Pr Jolyet, 33120 Arcachon, France
(2) IUFM Nord/Pas-de-Calais. UPRES-A CNRS ELICO. station marine, BP 80,
62930 Wimereux, France
d.vincent@biocean.u-bordeaux.fr
Abstract
Spatial and temporal short-term variations of zooplankton populations
were studied during oyster breeding in the most inner part of Arcachon
bav. This environment is submitted both to oceanic (bay of Biscay) and
continental (Leyre) inputs and its continental marshes are intensively
exploited for oyster farming.
This study is a first attempt to describe the zooplanktonic environment
of oyster larvae. Correspondence analyses showed that the mesozooplankton composition resulted from the mixingof several communities
dominated by copepods throughout the studv (64.3 ± 3.5
0 /n of total
abundance). Appendicularians and polychete larvac were the two other
dominant taxa (14.8 ± 6.0
( /o and 7.15 ± 3.8"/o, respectively). Three distinct
communities were observed:
(i) an autochtonous community with essentially Acartia discaudata, Acartia grani and Isias clavipes. ;
(ii) an inner community characterized by Acartia bifilosa and Acartia tonsa;
(iii) a neritic assemblage characterized by Paracalanus parvus and Penilia
avirostris.
Spatial and temporal variations of the communities were closely linked to
variations of environmental factors (temperature, salinitv and hvdrologv)
and particularly to changes in weather conditions. A storm event during
mid-August had an effect on the hydrodynamics in the bay with subsequent changes in the zooplankton communitv structure. lliis event resulted in a large scattering of holo- and meroplanktonic organisms (and
among them bivalve larvae).
Introduction
4'he knowledge of coastal ecosystems requires the studv of ecological
processes as well as the investigation of community stmctures. Zooplankton is an important biological component in semi-enclosed littoral
systems since both its high biomass and production rates can enhance
334