|   | 
Détails
   web
Enregistrements
Auteur (up) PERNET, F.; LAGARDE, F.; JEANNEE, N.; DAIGLE, G.; BARRET, J.; LE GALL, P.; QUERE, C.; ROQUE D'ORBCASTEL, E.
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 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
Lien permanent pour cet enregistrement
 

 
Auteur (up) SIMON, M.; FROMENTIN, J.-M.; BONHOMMEAU, S.; GAERTNER, D.; BRODZIAK, J.; ETIENNE, M.-P.
Titre Effects of Stochasticity in Early Life History on Steepness and Population Growth Rate Estimates: An Illustration on Atlantic Bluefin Tuna Type Article scientifique
Année 2012 Publication Plos One Revue Abrégée
Volume 7 Numéro 10 Pages e48583
Mots-Clés
Résumé The intrinsic population growth rate (r) of the surplus production function used in the biomass dynamic model and the steepness (h) of the stock-recruitment relationship used in age-structured population dynamics models are two key parameters in fish stock assessment. There is generally insufficient information in the data to estimate these parameters that thus have to be constrained. We developed methods to directly estimate the probability distributions of r and h for the Atlantic bluefin tuna (Thunnus thynnus, Scombridae), using all available biological and ecological information. We examined the existing literature to define appropriate probability distributions of key life history parameters associated with intrinsic growth rate and steepness, paying particular attention to the natural mortality for early life history stages. The estimated probability distribution of the population intrinsic growth rate was weakly informative, with an estimated mean r = 0.77 (+/-0.53) and an interquartile range of (0.34, 1.12). The estimated distribution of h was more informative, but also strongly asymmetric with an estimated mean h = 0.89 (+/-0.20) and a median of 0.99. We note that these two key demographic parameters strongly depend on the distribution of early life history mortality rate (M-0), which is known to exhibit high year-to-year variations. This variability results in a widely spread distribution of M-0 that affects the distribution of the intrinsic population growth rate and further makes the spawning stock biomass an inadequate proxy to predict recruitment levels.
Adresse Inst Natl Rech Agron, UMR AgroParistech INRA 518, Paris, France.
Auteur institutionnel Thèse
Editeur Public Library Science Lieu de Publication Éditeur
Langue 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 @ 22640 collection 995
Lien permanent pour cet enregistrement