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Auteur PERNET, F.; LAGARDE, F.; LE GALL, P.; ROQUE D'ORBCASTEL, E. url  openurl
  Titre Associations between farming practices and disease mortality of Pacific oyster Crassostrea gigas in a Mediterranean lagoon Type Article scientifique
  Année 2014 Publication Aquaculture Environment Interactions Revue Abrégée  
  Volume 5 Numéro 2 Pages 99-106  
  Mots-Clés Aquaculture; Epidemiology; OsHV-1; Shellfish farming  
  Résumé We present the first large-scale, high-resolution spatial and temporal pattern of disease mortality caused by Ostreid herpesvirus 1 (OsHV-1) that has affected Pacific oyster Crassostrea gigas in France every year since 2008, in relation to local farm use. Mortality was monitored in healthy oyster spat deployed at 106 locations in the Thau Mediterranean lagoon during the epizootic that occurred in spring 2011. We conducted a field survey of farming practices in the areas where the sentinel oysters were placed before the epizootic. We found that the risk of disease mortality in sentinel oysters was higher within the bivalve farming area than outside it, suggesting that the infection pressure is much higher in areas with intensive farming activity. The risk of mortality was higher in farms rearing spat, a developmental stage particularly susceptible to OsHV-1, than in farms rearing adult oysters, which are generally more resistant. Additionally, the mortality risk in farms rearing adult animals was similar to that in empty farms, which suggests that, during the study period, adult oysters did not vector the disease. Interestingly, the mortality risk for sentinel oysters deployed in mussel Mytilus galloprovincialis farms was lower than for those held in oyster farms or empty farms, suggesting that mussels reduced the infection pressure on susceptible oysters.  
  Adresse UMR LEMAR Ifremer CNRS UBO IRD, Technopole Brest Iroise, F-29280 Plouzane, France.  
  Auteur institutionnel Thèse  
  Editeur Inter-research Lieu de Publication Éditeur  
  Langue (up) Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1869-215x ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ 31248 collection 1217  
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Auteur PERNET, F.; LAGARDE, F.; JEANNEE, N.; DAIGLE, G.; BARRET, J.; LE GALL, P.; QUERE, C.; ROQUE D'ORBCASTEL, E. url  openurl
  Titre Spatial and Temporal Dynamics of Mass Mortalities in Oysters Is Influenced by Energetic Reserves and Food Quality Type Article scientifique
  Année 2014 Publication Plos One Revue Abrégée  
  Volume 9 Numéro 2 Pages e88469  
  Mots-Clés  
  Résumé Although spatial studies of diseases on land have a long history, far fewer have been made on aquatic diseases. Here, we present the first large-scale, high-resolution spatial and temporal representation of a mass mortality phenomenon cause by the Ostreid herpesvirus (OsHV-1) that has affected oysters (Crassostrea gigas) every year since 2008, in relation to their energetic reserves and the quality of their food. Disease mortality was investigated in healthy oysters deployed at 106 locations in the Thau Mediterranean lagoon before the start of the epizootic in spring 2011. We found that disease mortality of oysters showed strong spatial dependence clearly reflecting the epizootic process of local transmission. Disease initiated inside oyster farms spread rapidly beyond these areas. Local differences in energetic condition of oysters, partly driven by variation in food quality, played a significant role in the spatial and temporal dynamics of disease mortality. In particular, the relative contribution of diatoms to the diet of oysters was positively correlated with their energetic reserves, which in turn decreased the risk of disease mortality.  
  Adresse Univ Laval, Dept Math & Stat, Quebec City, PQ G1K 7P4, Canada.  
  Auteur institutionnel Thèse  
  Editeur Public Library Science Lieu de Publication Éditeur  
  Langue (up) Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1932-6203 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ 29249 collection 1218  
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Auteur CURY, P.M.; FROMENTIN, J.-M.; FIGUET, S.; BONHOMMEAU, S. url  openurl
  Titre Resolving Hjort's Dilemma How Is Recruitment Related to Spawning Stock Biomass in Marins Fish? Type Article scientifique
  Année 2014 Publication Oceanography Revue Abrégée  
  Volume 27 Numéro 4 Pages 42-47  
  Mots-Clés  
  Résumé The relationship between spawning fish abundance and the number of offspring, the so-called stock-recruitment relationship, is crucial for fisheries management and conservation measures. Using the most comprehensive data set ever assembled, we quantify this relationship for 211 fish stocks worldwide, revealing a global pattern with a pervasive asymptotic shape that shows increasing recruitment reaching an upper limit for values around half to two-thirds of parental biomass. This corroborates previous theoretical and modeling results. However, parental biomass is a predictor for only 5% to 15% of the variance in recruitment, demonstrating the weak predictive power of the stock-recruitment relationship in marine fish populations. Thus, there is a need to move rapidly toward models that integrate environmental conditions and species interactions in fisheries stock assessment and management, as suggested by Johan Hjort 100 years ago.  
  Adresse Institut français de recherche pour l'exploitation de la mer (IFREMER), Sète, France  
  Auteur institutionnel Thèse  
  Editeur The Oceanography Society Lieu de Publication Éditeur  
  Langue (up) Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1042-8275 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ 36441 collection 982  
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Auteur VAN BEVEREN, E.; BONHOMMEAU, S.; FROMENTIN, J.-M.; BIGOT, J.-L.; BOURDEIX, J.-H.; BROSSET, P.; ROOS, D.; SARAUX, C. url  openurl
  Titre Rapid changes in growth, condition, size and age of small pelagic fish in the Mediterranean Type Article scientifique
  Année 2014 Publication Marine Biology Revue Abrégée  
  Volume 161 Numéro 8 Pages 1809-1822  
  Mots-Clés  
  Résumé Since 2007, the ecosystem of the Gulf of Lions has shifted to a different regime, characterised by a low anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) biomass and a remarkably high sprat (Sprattus sprattus) biomass. Surprisingly, the abundance and recruitment of anchovy and sardine remained high. To understand which processes (bottom-up or top-down control, etc.) could have caused this shift, we studied the changes in body condition, growth and size and age of anchovy, sardine and sprat over 1984–1985 and 1992–2012, using data from scientific surveys. The annual age structure of anchovy and sardine was estimated using Bayesian mixture models based on size frequency data with priors on the age–length relationship derived from independent otolith readings. The results indicated periods during which anchovy and sardine were in an average (1992–2004), good (2005–2007) or poor (2008–2012) overall state of condition. For sardine, the shift towards smaller fish observed during these past 4 years was explained by a combination of slower growth and the disappearance of older individuals (ages 2+). Despite the increase in biomass of sprat since 2008, indications were found that sprat was also smaller than in the past. As growth and condition decreased and overexploitation has not been documented or suspected for those three species in this area, we propose that the current decline in sardine and anchovy biomass could be due to qualitative and/or quantitative modifications in the planktonic production (i.e. a bottom-up control) or mass mortalities of adults due to an epidemic disease.  
  Adresse Univ Montpellier 2, Res Unit EME UMR 212, F-34203 Sete, France.  
  Auteur institutionnel Thèse  
  Editeur Springer Lieu de Publication Éditeur  
  Langue (up) Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0025-3162 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ 30335 collection 986  
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Auteur Collos, Y.; Jauzein, C.; Ratmaya, W.; Souchu, P.; Abadie, E.; Vaquer, A. url  doi
openurl 
  Titre Comparing diatom and Alexandrium catenella/tamarense blooms in Thau lagoon: Importance of dissolved organic nitrogen in seasonally N-limited systems Type Article scientifique
  Année 2014 Publication Revue Abrégée Harmful Algae  
  Volume 37 Numéro Pages 84-91  
  Mots-Clés Ammonium; Growth rate; Non classical blooms; Organic nitrogen; alexandrium catenella/tamarense  
  Résumé Diatom blooms in Thau lagoon are always related to rain events leading to inputs of inorganic nutrients such as phosphate, ammonium and nitrate through the watershed with time lags of about 1 week. In contrast, blooms of Alexandrium catenella/tamarense can occur following periods of 3 weeks without precipitation and no significant input of conventional nutrients such as nitrate and phosphate. Field results also indicate a significant drop (from 22–25 to 15–16 μM over 3 days) in dissolved organic nitrogen (DON) at the bloom peak, as well as a significant inverse relationship between A. catenella/tamarense cell density and DON concentrations that is not apparent for diatom blooms. Such dinoflagellate blooms are also associated with elevated (6–9 μM) ammonium concentrations, a curious feature also observed by other investigators, possibly the results of ammonium excretion by this organism during urea or other organic nitrogen assimilation. The potential use of DON by this organism represents short cuts in the nitrogen cycle between plants and nutrients and requires a new model for phytoplankton growth that is different from the classical diatom bloom model. In contrast to such diatom blooms that are due to conventional (nitrate, phosphate) nutrient pulses, Alexandrium catenella/tamarense blooms on the monthly time scale are due to organic nutrient enrichment, a feature that allows net growth rates of about 1.3 d−1, a value higher than that generally attributed to such organisms.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue (up) Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1568-9883 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 475  
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