|   | 
Détails
   web
Enregistrements
Auteur Albouy, C.; Velez, L.; Coll, M.; Colloca, F.; Le Loc'h, F.; Mouillot, D.; Gravel, D.
Titre From projected species distribution to food-web structure under climate change Type Article scientifique
Année 2014 Publication Revue Abrégée Global Change Biology
Volume 20 Numéro 3 Pages 730-741
Mots-Clés climate change; connectance; fish body size; food-webs; generality; Mediterranean Sea; metaweb; niche model; vulnerability
Résumé
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur (up)
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1354-1013 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel LL @ pixluser @ collection 324
Lien permanent pour cet enregistrement
 

 
Auteur Alegre, A.; Ménard, F.; Tafur, R.; Espinoza, P.; Arguelles, J.; Maehara, V.; Flores, O.; Simier, M.; Bertrand, A.
Titre Comprehensive model of jumbo squid Dosidicus gigas trophic ecology in the Northern Humboldt Current System Type Article scientifique
Année 2014 Publication Revue Abrégée Plos One
Volume 9 Numéro 1 Pages
Mots-Clés
Résumé The jumbo squid Dosidicus gigas plays an important role in marine food webs both as predator and prey. We investigated the ontogenetic and spatiotemporal variability of the diet composition of jumbo squid in the northern Humboldt Current system. For that purpose we applied several statistical methods to an extensive dataset of 3,618 jumbo squid non empty stomachs collected off Peru from 2004 to 2011. A total of 55 prey taxa was identified that we aggregated into eleven groups. Our results evidenced a large variability in prey composition as already observed in other systems. However, our data do not support the hypothesis that jumbo squids select the most abundant or energetic taxon in a prey assemblage, neglecting the other available prey. Indeed, multinomial model predictions showed that stomach fullness increased with the number of prey taxa, while most stomachs with low contents contained one or two prey taxa only. Our results therefore question the common hypothesis that predators seek locally dense aggregations of monospecific prey. In addition D. gigas consumes very few anchovy Engraulis ringens in Peru, whereas a tremendous biomass of anchovy is potentially available. It seems that D. gigas cannot reach the oxygen unsaturated waters very close to the coast, where the bulk of anchovy occurs. Indeed, even if jumbo squid can forage in hypoxic deep waters during the day, surface normoxic waters are then required to recover its maintenance respiration (or energy?). Oxygen concentration could thus limit the co-occurrence of both species and then preclude predator-prey interactions. Finally we propose a conceptual model illustrating the opportunistic foraging behaviour of jumbo squid impacted by ontogenetic migration and potentially constrained by oxygen saturation in surface waters.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur (up)
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 LL @ pixluser @ collection 325
Lien permanent pour cet enregistrement
 

 
Auteur Bodin, N.; Tapie, N.; Le Menach, K.; Chassot, E.; Elie, P.; Rochard, E.; Budzinski, H.
Titre PCB contamination in fish community from the Gironde Estuary (France) : blast from the past Type Article scientifique
Année 2014 Publication Revue Abrégée Chemosphere
Volume 98 Numéro Pages 66-72
Mots-Clés Bioindicators; Biomagnification; Fish assemblage; Food safety; Persistent organic pollutants (POPs)
Résumé The contamination of the Gironde Estuary, southwest of France, by polychlorinated biphenyls (PCBs) was assessed using six fish of high ecological and economic importance as bioindicator species. The concentrations of 21 PCB congeners and total fat contents were determined in the muscle and liver of eels (Anguilla anguilla), seabass (Dicentrarchus labrax), flounders (Platichthys flesus), meagres (Argyrosomus regius), mullets (Liza ramada), and soles (Solea vulgaris). In addition, information regarding the trophic ecology of the studied fish was obtained through the analysis of carbon and nitrogen stable isotopes (i.e., delta C-13 and delta N-15) in muscle. Results revealed high PCB concentrations in fish compared to monitored European estuaries. The muscle of eels was by far the most contaminated fish flesh (Sigma(7)PCBs = 1000 +/- 440 ng g(-1), on a dry weight basis), while the higher PCB concentrations in liver were measured in flounder (Sigma(7)PCBs = 2040 +/- 1160 ng g(-1), d.w.). A quantile regression approach allowed to investigate the fate of PCBs in the Gironde estuarine fish assemblage, and revealed a general process of trophic magnification. Finally, most of the analysed fish presented PCB concentrations in muscle meat above the current European maximum limits for sea products, while the derived “Toxic Equivalent Quantity” (TEQ) revealed human health concerns only for high-fat fish consumption.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur (up)
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0045-6535 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel LL @ pixluser @ collection 326
Lien permanent pour cet enregistrement
 

 
Auteur Dueri, S.; Bopp, L.; Maury, O.
Titre Projecting the impacts of climate change on skipjack tuna abundance and spatial distribution Type Article scientifique
Année 2014 Publication Revue Abrégée Global Change Biology
Volume 20 Numéro 3 Pages 742-753
Mots-Clés Apecosm-E; Atlantic Ocean; global warming; Indian Ocean; Katsuwonus pelamis; Pacific Ocean; scenario; Tropical tuna
Résumé Climate-induced changes in the physical, chemical, and biological environment are expected to increasingly stress marine ecosystems, with important consequences for fisheries exploitation. Here, we use the APECOSM-E numerical model (Apex Predator ECOSystem Model – Estimation) to evaluate the future impacts of climate change on the physiology, spatial distribution, and abundance of skipjack tuna, the worldwide most fished species of tropical tuna. The main novelties of our approach lie in the mechanistic link between environmental factors, metabolic rates, and behavioral responses and in the fully three dimensional representation of habitat and population abundance. Physical and biogeochemical fields used to force the model are provided by the last generation of the IPSL-CM5 Earth System Model run from 1990 to 2100 under a &8216;business-as-usual&8217; scenario (RCP8.5). Our simulations show significant changes in the spatial distribution of skipjack tuna suitable habitat, as well as in their population abundance. The model projects deterioration of skipjack habitat in most tropical waters and an improvement of habitat at higher latitudes. The primary driver of habitat changes is ocean warming, followed by food density changes. Our projections show an increase of global skipjack biomass between 2010 and 2050 followed by a marked decrease between 2050 and 2095. Spawning rates are consistent with population trends, showing that spawning depends primarily on the adult biomass. On the other hand, growth rates display very smooth temporal changes, suggesting that the ability of skipjack to keep high metabolic rates in the changing environment is generally effective. Uncertainties related to our model spatial resolution, to the lack or simplification of key processes and to the climate forcings are discussed.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur (up)
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1354-1013 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel LL @ pixluser @ collection 327
Lien permanent pour cet enregistrement
 

 
Auteur Chu, Y.; Tournoud, M.G.; Salles, C.; Got, P.; Perrin, J.L.; Rodier, C.; Caro, A.; Troussellier, M.
Titre Spatial and temporal dynamics of bacterial contamination in South France coastal rivers: focus on in-stream processes during low flows and floods Type Article scientifique
Année 2014 Publication Revue Abrégée Hydrological Processes
Volume 28 Numéro 8 Pages 3300-3313
Mots-Clés Coliforms and streptococci; Mediterranean rivers; faecal indicator loads; flush effect; point sources; riverbed sediment abundance
Résumé
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur (up)
Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0885-6087 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 839
Lien permanent pour cet enregistrement