Consulta: subjectFacets:"Marennes Oleron"
Registros recuperados: 16
Data/hora: 03/06/2024 17:21:38

Feeding of Crassostrea gigas at high seston load : modeling requirements
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Barille, Laurent; Prou, Jean.
Ecophysiological experiments conducted in situ in the Bay of Marennes-Oléron during a spring and neap tide cycle in May 1991 , were designed to get a better representation of 2 important components of the energy budget of the Japanese oyster Crassostrea gigas : clearance rate and selection efficiency. The relationships previously established by Raillard et al. ( 1993) are re-evaluated by integrating the effects of high seston loads, typical of tidal effect within estuaries, on the physiological processes. For the clearance rate, the re-evaluated parameterization includes: - a negative effect of turbidity. - a clogging threshold set to 192 mg/l. Selection efficiency parameterizations are modified by incorporating : - a constant inorganic ingestion for...
Tipo: Text
Palavras-chave: Matematical model; Oyster; Crassostrea gigas; Clearance rate; Seclection efficency; Marennes Oleron; Charente Maritime.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/00102/21299/18913.pdf

Stable isotope analysis position of intertidal of food source and trophic nematodes and copepods
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Rzeznik Orignac, J; Boucher, G; Fichet, Denis; Richard, P.
Four dominant nematode species and various copepods from an intertidal mudflat in Marennes-Oleron Bay were analyzed for delta C-13 and delta N-15 ratios together with their potential food source, the microphytobenthos. It was shown that microphytobenthic C is passed to nematodes either by grazing or predation on herbivorous meiofauna by other nematodes. Diatoms of different sizes exhibited different C-13 content, which can be reflected in herbivorous meiofauna, such as the nematodes Daptonema oxycerca and Metachromadora remanei and the bulk of copepods, indicating they can select different sizes of diatoms. Results confirm the need to analyze meiofauna feeding habits at the species or genera level since the delta N-15 and delta C-13 signatures differed...
Tipo: Text
Palavras-chave: Stable isotopes; Marennes Oleron; Mudflat; Food web; Benthic diatoms; Microphytobenthos; Meiofauna; Copepods; Nematodes.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-4292.pdf

Etude préliminaire de l'impact des huîtres Crassostrea gigas (Thunberg) en élevage sur la biomasse des microorganismes des claires de Marennes-Oléron
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Zanette, Yvan; Garnier, Jacqueline.
The evolution of microbial biomass based on chlorophyll a, pheopigments, proteins, particulate carbon and nitrogen, ATP and total viable aerobic bacterias measurements, is studied on three oyster ponds in relation with different densities of reared oysters Crassostrea gigas (Thunberg). Chlorophyll a important amounts characteristics of theses middles (13 to 100µg.1(1) are in part consumed when the density of oysters is important, comparatively ATP increase to 30µg.1(1). With important values of (ATP/carbon) 10(3) ratios, upper than 10, we could think that the development of large silicified phytoplanktonic species should be favoured by oysters particularly the diatom Navicula ostrearia (Bory)
Tipo: Text
Palavras-chave: Navicula ostrearia; Marennes Oleron; Phytoplanctonic biomass; Microbial biomass; Oysters; Crassostrea gigas; Navicula ostrearia; Marennes Oléron; Claire; Biomasse microbienne; Biomasse phytoplanctonique; Huîtres; Crassostrea gigas.
Ano: 1981
URL: http://archimer.ifremer.fr/doc/1981/acte-2936.pdf

Difficulties in sampling for estimation of phytoplankton biomass in estuarine conditions : variabilities and precisions at different temporal scales in the case of the bay Marennes Oleron
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Heral, Maurice; Goulletquer, Philippe; Razet, Daniel; Prou, Jean; Ravail, Brigitte; Maestrini, Serge.
Different sampling strategies have been tested for estimation of phytoplanktonic biomasses in a bay submitted to estuarine conditions and high velocity of currents. Daily variations showed that for a precision of 5% of the daily mean, it is necessary to sample with a 1 hour and a half time scale. Systematic sampling appears to be more preceise than the random sampling. A sampling during 35 days at low tide and at high tide, during the phytoplanktonic bloom, showed the large variability between the days. A precision of 30% of the mean biomass of the month is obtained with a 8 days time scale. Comparison between tidal cycle sampling (10% of precision) with a punctual sample in the middle of the day did not show large differences. As the main variability is...
Tipo: Text
Palavras-chave: Marennes Oleron; Phytoplanktonic biomasses; Estimation.
Ano: 1988
URL: http://archimer.ifremer.fr/doc/1988/acte-2877.pdf

Stock assesments of the non-cultivated molluscs in the oyster culture area of Marennes Oleron
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Sauriau, Pierre-guy.
A quantitative sampling was made on the non-cultivated molluscs of the soft bottom macrofauna in the bay of Marennes-Oleron. A stratified random sampling, including an optimal allocation strategy. provided adequate data to estimate abundance and biomass (total weight. dry weight and ash-free-dry weight) of each molluscan species. The main stratification factors were respectively the bathymetric levels. the different types of sediment and the differences between natural, oyster-free mud flats and cultivated areas. A Smith Mc-Intyre grab was used to sample the subtidal, shallow areas and the tidal flats as well. The total number of sampling stations was 370. The final estimation of the total weight of benthic molluscs was 14,400  ± 3,000 tons (at 95 %...
Tipo: Text
Palavras-chave: Marennes Oleron; Non cultivated benthic molluscs; Biomass; Stock assessments; Stratrification; Sampling; Marennes Oléron; Molluques benthiques non cultivés; Biomasse; Stocks; Stratification; Echantillonnage.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/1987/publication-2867.pdf

Effet des biodépôts de l'huître Crassostrea gigas (Thunberg) sur l'accumulation de matières organiques dans les parcs du bassin de Marennes-Oléron
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Sornin, Jean-marc; Feuillet, Michelle; Heral, Maurice; Deslous-paoli, Jean-marc.
The accumulation of biodeposits brings about geochemical modifications of the underlying sediment, that are noticeable. The increase can reach 83% of the amount of organic carbon. By catching the deposits on the spot and by gathering them directly from the oyster tables we get a daily deposit that can weigh, according to season, between 8 and 99 g of carbon a square meter. The recycling of important quantities of organic matter increase the oxygen needs and the most reducing environment provides opportunities for ammonification and reduction of sulfate into sulfur. So we can consider that there is as much as 4 times more sulfurous hydrogen in intensive oyster-growing areas. This output of sulfurs seems to cause the oyster filtration some damage (Ito et...
Tipo: Text
Palavras-chave: Marennes Oleron; Sediment; Oysters; Physiology; Filtration; Biodeposits; Crassostrea gigas; Marennes Oléron; Sédiment; Huître; Physilogie; Filtration; Biodépôts; Crassostrea gigas.
Ano: 1983
URL: http://archimer.ifremer.fr/doc/1983/acte-2955.pdf

Seuil de production de pseudo-fécès de l'huître creuse du Pacifique : Crassostrea gigas (Thunberg) dans des conditions de faibles charges particulaires
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Soletchnik, Patrick; Goulletquer, Philippe; Geairon, Philippe; Razet, Daniel.
This study is part of a comprehensive research program focusing on the oyster shellfish management in the Marennes-Oleron Bay: Within this program, a task aimed to develop a biological model of the Pacific cupped oyster Crassostrea gigas. Our study addressed the issue of pseudo-faeces production threshold under various diet quality levels. Pseudo-faeces sampling was carried out using particulate matter concentration below Il mg 1-1 The various modalities prompted us to define two pseudo-faeces production models. The first model was developed using natural seawater. The organic matter ratio ranged from 25 to 45% while the pseudo-faeces production threshold reached 2.9 to 4.4 mg 1-1 of total particulate matter. The second model was established using seawater...
Tipo: Text
Palavras-chave: Marennes Oleron; Pseudo faeces; Crassostrea gigas; Oysters; Biological model; Marennes Oléron; Pseudo fécès; Crassostrea gigas; Huîtres; Modèle biologique.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/1996/publication-3087.pdf

Limiting nutrients of oyster pond seawater in the Marennes-Oleron region for Haslea ostrearia : applications to the mass production of the diatom in mesocosom experiments
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Turpin, Vincent; Robert, Jean-michel; Goulletquer, Philippe.
Bioassays were carried out with the 'blue diatom' Haslea ostrearia Simonsen, which is responsible for oyster greening during the fattening period of Crassostrea gigas Thunberg in oyster ponds. Samples of seawater were taken from two oyster ponds: one without oysters and the other with 20 oysters per m_, maximal density allowed by the French AFNOR norm for 'refinement'. The aims were to clarify the nutrient requirements of this diatom, also to elucidate the eventual influence of C. gigas at this density on the seawater fertility and to envisage the mass production of this diatom by pond fertilization. Examination of cell numeric densities at the end of bioassays allows us to conclude that silicate was the first limiting nutrient, closely followed by...
Tipo: Text
Palavras-chave: Marennes Oleron; Oyster ponds; Mesocosm experiment; Bioassay; Haslea ostrearia; Bacillariophyceae; Limiting nutrients; Marennes Oléron; Claires à huîtres; Expérience en mésocosmes; Bioessai; Haslea ostrearia; Bacillariophyceae; Nutriments limitants.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/1999/publication-3096.pdf

Dynamics of spatial patterns of microphytobenthic biomass: inferences from a geostatistical analyisis of two comprenhensive surveys in Marennes-Oléron Bay (France)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Guarini, Jean-marc; Blanchard, Gerard; Bacher, Cedric; Gros, Philippe; Riera, Pascal; Richard, Pierre; Gouleau, Dominique; Galois, Robert; Prou, Jean; Sauriau, Pierre-guy.
Microphytobenthos plays an important role as primary producer in shallow embayments subject to a tidal regime. The present paper aims to characterize the spatial patterns of sedimentary chlorophyll a (chl a) biomass in 2 seasons in the wide intertidal mudflats of the Marennes-Oleron Bay (France); furthermore, it provides estimates of total microphytobenthic biomass. Accordingly, a systematic sampling scheme was performed in June 1995 and in January 1996. On average, biomass was higher in June (ca 120 mg chl a m-2) than in January (ca 85 mg chl a m-2). Moreover, the geostatistical analysis revealed that spatial similarities were propagated over larger distances in June (6 km) than in January (2.2 km). In order to account for this result , we suggest that...
Tipo: Text
Palavras-chave: Marennes Oleron; Intertidal mudflat; Geostatistics; Spatial distribution; Chrlorophyll a; Microphytobenthos.
Ano: 1998
URL: https://archimer.ifremer.fr/doc/1998/publication-3820.pdf

The measurements of nutrient fluxes at the water-sediment interface : incubation methods (in laboratory and in situ) ; gradient method (calculated fluxes) ; benthic ecosystem tunnel
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Feuillet-girard, Michelle; Gouleau, Dominique; Zurburg, Wouter; Small, A. C.; Dankers, N.; Heral, Maurice.
Many flux measurements methods have been described in the literature. The purpose of our study was to compare results obtained by these different methods : gradient method, incubation method (Laboratory and in situ), benthic ecosystem tunnel. The field experiment has been performed in the Marennes Oleron Bay since May 1991 (Contrat C. E. E. FAR)
Tipo: Text
Palavras-chave: Nutrient fluxes; Measurements; Methods; Incubation; Benthic ecosystem tunnel; Marennes Oleron; Charente Maritime.
Ano: 1992
URL: http://archimer.ifremer.fr/doc/00102/21304/18923.pdf

Croissance et qualité de l'huître Crassostrea gigas Thunberg en élevage dans le bassin de Marennes-Oléron
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Deslous-paoli, Jean-marc.
In 1979-1980, the main growth o oysters Crassostrea gigas, in the basin of Marennes-Oleron occured in June and July. The available amount of food and the energetic requirements for the reproduction are important factors determining growth. Tissue weight decreased after spawning until the end of the winter, and this decrease might be related to the high quantities of inorganic particles, in the seston, at that period of the year.
Tipo: Text
Palavras-chave: Marennes Oleron; Seston; Growth; Crassostrea gigas; Oysters; Marennes Oléron; Seston minéral; Croissance; Crassostrea gigas; Huîtres.
Ano: 1982
URL: http://archimer.ifremer.fr/doc/1982/publication-2947.pdf

Assessments of natural mortality of cultivated oysters (Crassostrea gigas) in the bay of Marennes-Oleron (France)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Bodoy, Alain.
The natural mortality of oysters could by considered, in a man controlled ecosystem, as the result of the action of biological factors, and human factors other then the harvest of the population. Such mortalities need to be estimated in order to be used in population dynamics, as a tool for management purposes. ln Marennes-Oleron bay, different ways of estimating the natural mortality are available. Several oyster farms were monitored for assessing growth, mortality and production in rearing conditions. Furthermore, an experimental framework which includes 15 stations gave an appraisal of the same factors under controlled conditions. Finally, another estimate will be soon available by comparin9 the number of recruited oysters, and the number of oyster...
Tipo: Text
Palavras-chave: Marennes Oleron; Mortality; Crassostrea gigas; Oysters.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/1986/acte-2962.pdf

Perspectives de développement de l'élevage de la palourde japonaise Ruditapes philippinarum dans le bassin ostréicole de Marennes-Oléron
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Goulletquer, Philippe; Nedhif, Mohamed; Heral, Maurice.
The complete Manila clam's breeding cycle (Ruditapes philippinarum ) in oysters ponds (claires) permits  to obtain a length of 25 mm after 1 year with a density range of 200 animals/m2 . As the primary production is restricted, the breeding biomass during the second year is limited to 500 g.m2 corresponding to a density between 30 to 50 clams..m-2. For an increase of the production it is necessary to extend the cultivated area to the tida1 bottom of the Bay of Marennes-Oleron. It appears that the man tidal level between + 2 and + 2.5 15 necessary with a density range of 200.m-2 to reach, the market size nine months later. The harvest sould be done before winter time to avoid a large 1055 of the flesh which can cause high levels of mortality.
Tipo: Text
Palavras-chave: Marennes Oleron; Breeding; Clams; Ruditapes philippinarum; Marennes Oléron; Elevage; Palourdes; Ruditapes philippinarum.
Ano: 1986
URL: http://archimer.ifremer.fr/doc/1986/acte-2966.pdf

An example of GIS potentiality for coastal zone management: preselection of submerged oyster culture areas near Marennes-Oleron (France)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Durand, H.; Guillaumont, Brigitte; Loarer, Ronan; Loubersac, Lionel; Heral, Maurice; Prou, Jean.
The Charente Maritime coast, in central western France, is the most important area for oyster and mussel production in Europe. High density, in this restricted intertidal area, induces low growing rate and socio-economic difficulties. One of the possible solutions is to shift some oysters from intertidal area to submerged areas. Bathymetry, sedimentology, hydrodynamism, fisheries and administrative rules are some conditions which are considered to establish the better selection of potential zone. The successive steps of setting up the prototype of GIS are presented: digitized traditional data from charts, extracted data from grid models (hydrodynmaic model), merging of thematic covers, proposal of favorable areas. The results are discussed especially on...
Tipo: Text
Palavras-chave: GIS; Modelisation; Bathymetry; Sedimentology; Hydrodynamism; Marennes Oleron.
Ano: 1994
URL: http://archimer.ifremer.fr/doc/00017/12784/9725.pdf

Approche de l'état physiologique de l'huître creuse Crassostrea gigas au cours d'un cycle saisonnier à Marennes-Oléron
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Moal, Jeanne; Samain, Jean-francois; Bodoy, Alain; Le Coz, Jean-rene.
The energy charge was measured for two Crassostrea gigas populations, during an annual survey at Marennes Oleron, to appreciate the condition of health of these oysters. It is assumed that the actual decrease in production of this area is related to a biomass overload which affects the oysters by lowering their scope for growth. Energy charge, an index developped by ATKINSON (1968), defines the energy equilibrium of organisms. It is the adenylic nucleotide ratio: E.C = (ATP + 1/2ADP)/ATP + ADP + AMP). We have measured this parameter to determine the state of health of these oysters. A methodological study has been conducted previously to define the conditions of sampling, conservation and extraction for a HPLC assay. The HPLC method (high performance...
Tipo: Text
Palavras-chave: Marennes Oleron; Seasonal variations; Crassostrea gigas; Physiological indice; Nucleotides; Energy charge; Marennes Oléron; Cycle saisonnier; Crassostrea gigas; Indiced physiologique; Nucléotides; Charge énergétique.
Ano: 1987
URL: http://archimer.ifremer.fr/doc/1987/publication-2869.pdf

Répartition géographique et structure de population de Crepidula fornicata Linné dans le bassin de Marennes-Oléron en 1981 et 1982
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Deslous-paoli, Jean-marc; Masse, Henri.
Hundred and ten samplings were made in the bay of Marennes Oleron, during the summer 1981. They allow to localize the hight loads of Crepidula fornicata in the middle of the bay (along the mud-bank of Charret and in the courante d'Oleron°.  In this two Points, we value the dry biomass at about 2,3 kg/m2 on the mud-bank of Charret and at 1,1 kg/m2 in the courante d'Oleron. The weight present on this two banks (about 550 000 m2) is approximatively 700 tons of slipper limpets. The mean growth rate is 20, 19, 17 and 12 mm respectively on the 1"-, 2n ,3rd and  4th year with a very important variability since the first year. 74,5 %of the individuals form the main chains (mean of 6 slipper limpets) attached on shells of dead slipper limpets.  Some solutions of...
Tipo: Text
Palavras-chave: France; Marennes Oleron; Geographical repartition; Crepidula fornica; Répartion géographique; Marennes Oléron; Crepidula fornicata; Crépidules.
Ano: 1982
URL: http://archimer.ifremer.fr/doc/1982/acte-2950.pdf