|   | 
Détails
   web
Enregistrements
Auteur Pellissier, L.; Leprieur, F.; Parravicini, V.; Cowman, P.F.; Kulbicki, M.; Litsios, G.; Olsen, S.M.; Wisz, M.S.; Bellwood, D.R.; Mouillot, D.
Titre Quaternary coral reef refugia preserved fish diversity Type Article scientifique
Année 2014 Publication Revue Abrégée Science
Volume (down) 344 Numéro 6187 Pages 1016-1019
Mots-Clés abundance; areas; assembly rules; cradles; global patterns; gradient; hotspots; marine biodiversity; museums; species richness
Résumé The most prominent pattern in global marine biogeography is the biodiversity peak in the Indo-Australian Archipelago. Yet the processes that underpin this pattern are still actively debated. By reconstructing global marine paleoenvironments over the past 3 million years on the basis of sediment cores, we assessed the extent to which Quaternary climate fluctuations can explain global variation in current reef fish richness. Comparing global historical coral reef habitat availability with the present-day distribution of 6316 reef fish species, we find that distance from stable coral reef habitats during historical periods of habitat loss explains 62% of the variation in fish richness, outweighing present-day environmental factors. Our results highlight the importance of habitat persistence during periods of climate change for preserving marine biodiversity.
Adresse
Auteur institutionnel Thèse
Editeur Lieu de Publication Éditeur
Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0036-8075 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 801
Lien permanent pour cet enregistrement
 

 
Auteur Hadjadji, I.; Frehi, H.; Ayada, L.; Abadie, E.; Collos, Y.
Titre A comparative analysis of Alexandrium catenella/tamarense blooms in Annaba Bay (Algeria) and Thau lagoon (France); phosphorus limitation as a trigger Type Article scientifique
Année 2014 Publication Revue Abrégée Comptes Rendus Biologies
Volume (down) 337 Numéro 2 Pages 117-122
Mots-Clés Algeria; Algérie; Efflorescences; France; Méditerranée; alexandrium catenella/tamarense; blooms; mediterranean
Résumé
Adresse
Auteur institutionnel Thèse
Editeur 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 1631-0691 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 397
Lien permanent pour cet enregistrement
 

 
Auteur Boyd, C.; Punt, A.E.; Weimerskirch, H.; Bertrand, S.
Titre Movement models provide insights into variation in the foraging effort of central place foragers Type Article scientifique
Année 2014 Publication Revue Abrégée Ecological Modelling
Volume (down) 286 Numéro Pages 13-25
Mots-Clés Animal movement; Foraging ecology; Hidden Markov model; Provisioning theory; Seabirds; Sula variegata
Résumé Ecology and conservation depend on an understanding of how animals adjust their behaviour patterns in response to changes in their environment. Central place foragers (CPFs) are well-suited for developing ecological models of adaptive processes because their objective functions and operational constraints can be reasonably inferred. Central place foraging and provisioning theory provide the theoretical framework for this analysis. Analysis of CPF time allocation and energy budgets can provide insights into their strategies for responding to environmental variation. However, until recently, suitable high-resolution data on the behaviour of seabirds and other CPFs at sea have not been available. Previous studies of breeding seabirds have investigated variation in foraging trip duration and colony attendance, but few studies have analyzed variation in time allocation within foraging trips. Here, we develop a conceptual energy-based model for analysing variation in the time allocation of CPFs during foraging trips, and apply it to the movement patterns of Peruvian boobies (Sula variegata). Foraging trips of Peruvian boobies, recorded using high-resolution global positioning systems (GPS), were first partitioned into movement modes consistent with travel and foraging behaviours using a hidden Markov model (HMM) adapted to account for gaps in the GPS tracks associated with diving behaviour. Analysis of the HMM results based on the conceptual model indicated that differences in foraging effort between two treatments were best explained by a combination of differences in travel time and in time spent searching for prey. The conceptual model provides the basis for an integrated approach to analysis of variation in foraging strategies in which identification of various behaviours is coupled with assessments of time and energy budgets. This integrated approach can contribute to greater understanding of the processes determining foraging strategies and the limits to these strategies in the context of competition for resources and global climate change.
Adresse
Auteur institutionnel Thèse
Editeur 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 0304-3800 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel LL @ pixluser @ collection 355
Lien permanent pour cet enregistrement
 

 
Auteur Neira, S.; Moloney, C.; Christensen, V.; Cury, P.; Shannon, L.; Arancibia, H.
Titre Analysing changes in the southern Humboldt ecosystem for the period 1970-2004 by means of dynamic food web modelling Type Article scientifique
Année 2014 Publication Revue Abrégée Ecological Modelling
Volume (down) 274 Numéro Pages 41-49
Mots-Clés Ecopath with Ecosim; Fishing patterns; Physical forcing; Regime shifts; Southern Humboldt; Trophic controls
Résumé A 22-group Ecopath model representing the southern Humboldt (SH) upwelling system in the year 1970 is constructed. The model is projected forward in time and fitted to available time series of relative biomass, catch and fishing mortality for the main fishery resources. The time series cover the period 1970 to 2004 and the fitting is conducted using the Ecopath with Ecosim (EwE) software version 5.1. The aim is to explore the relative importance of internal (trophic control) and external (fishing, physical variability) forcing on the dynamics of commercial stocks and the Southern Chilean food web. Wide decadal oscillations are observed in the biomass of commercial stocks during the analyzed period. Fishing mortality explains 21% of the variability in the time series, whereas vulnerability (v) parameters estimated using EwE explain an additional 20%. When a function affecting primary production (PP) is calculated by Ecosim to minimize the sum of squares of the time series, a further 28% of variability is explained. The best fit is obtained by using the fishing mortality time series and by searching for the best combination of v parameters and the PP function simultaneously, accounting for 69% of total variability in the time series. The PP function obtained from the best fit significantly correlates with independent time series of an upwelling index (UI; rho = 0.47, p<0.05) and sea surface temperature (SST; rho = -0.45, p<0.05), representing environmental conditions in the study area during the same period of time. These results suggest that the SH ecosystem experienced at least two different environmentally distinct periods in the last three decades: (i) from 1970 to 1985 a relatively warm period with low levels of upwelling and PP, and (ii) from 1985 to 2004 a relatively cold period with increased upwelling and PP. This environmental variability can explain some of the changes in the food webs. Fishing (catch rate) and the environment (bottom-up anomaly in PP) appear to have affected the SH both at the stock and at the food web level between 1970 and 2004. The vulnerability setting indicates that the effects of external forcing factors may have been mediated by trophic controls operating in the food web.
Adresse
Auteur institutionnel Thèse
Editeur 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 0304-3800 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel LL @ pixluser @ collection 330
Lien permanent pour cet enregistrement
 

 
Auteur Bodin, N.; Lucas, V.; Dewals, P.; Adeline, M.; Esparon, J.; Chassot, E.
Titre Effect of brine immersion freezing on the determination of ecological tracers in fish Type Article scientifique
Année 2014 Publication Revue Abrégée European Food Research and Technology
Volume (down) 238 Numéro 6 Pages 1057-1062
Mots-Clés Brine immersion; Fatty acids; Frozen storage; Large pelagic fish; Persistent organic pollutants; Stable isotopes
Résumé The use of a multi-ecological tracer approach provides valuable and complementary insights to investigate the complex biology and ecology of large pelagic fish. Brine immersion freezing is the most common preservation technique used onboard for large fish to be frozen whole until they are delivered for sale and processing. We evaluated the effect of brine freezing on lipid and fatty acid composition, C and N stable isotope ratios, and organochlorine contaminant levels of yellowfin tuna (Thunnus albacares) and skipjack tuna (Katsuwonus pelamis). Fresh tunas were stored in a saturated sodium chlorine brine immersion tank maintained at -20 A degrees C for 6 weeks, and ecological tracers were analysed on dorsal muscle samples collected before and after brine freezing. No significant effect of the fish preservation technique was found except for delta N-15 whose signatures slightly increased after a 6-week period of brine immersion. Because N isotopic shift was close to the analytical precision and probably related to a higher risk of salt penetration in small tunas with abraded skin, we consider our results as conservative and conclude that ecological tracers can indeed be analysed on brine-freezing-preserved tunas.
Adresse
Auteur institutionnel Thèse
Editeur 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 1438-2377 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel LL @ pixluser @ collection 353
Lien permanent pour cet enregistrement