bascule de visibilité Search & Display Options

Tout Sélectionner    Désélectionner
 |   | 
Détails
   print
  Enregistrements Liens
Auteur Guilhaumon, F.; Albouy, C.; Claudet, J.; Velez, L.; Ben Rais Lasram, F.; Tomasini, J.-A.; Douzery, E.J.P.; Meynard, C.N.; Mouquet, N.; Troussellier, M.; Araújo, M.B.; Mouillot, D. url  doi
openurl 
  Titre Representing taxonomic, phylogenetic and functional diversity: new challenges for Mediterranean marine-protected areas Type Article scientifique
  Année 2015 Publication (down) Revue Abrégée Diversity Distrib.  
  Volume 21 Numéro 2 Pages 175-187  
  Mots-Clés Functional diversity; Gap analysis; marine-protected area; Mediterranean fishes; phylogenetic diversity; reserves; taxonomic diversity  
  Résumé Aim To assess gaps in the representation of taxonomic, phylogenetic and functional diversity among coastal fishes in Mediterranean marine-protected areas (MPAs). Location Mediterranean Sea. Methods We first assessed gaps in the taxonomic representation of the 340 coastal fish species in Mediterranean MPAs, with representation targets (the species range proportion to be covered by MPAs) set to be inversely proportional to species' range sizes. We then asked whether MPAs favoured representation of phylogenetically and functionally more distinct species or whether there was a tendency to favour less distinctive ones. We finally evaluated the overall conservation effectiveness of the MPAs using a metric that integrates species' phylogenetic and functional relationships and targets achievement. The effectiveness of the MPA system at protecting biodiversity was assessed by comparison of its achievements against a null model obtained by siting current MPAs at random over the study area. Results Among the coastal fish species analysed, 16 species were not covered by any MPA. All the remaining species only partially achieved the pre-defined representation target. The current MPA system missed fewer species than expected from siting MPAs at random. However, c. 70% of the species did not achieve better protection in the current MPAs than expected from siting MPAs at random. Functional and evolutionary distinctiveness were weakly correlated with target achievement. The observed coverage of taxonomic, phylogenetic and functional diversity was not different or lower than expected from siting MPAs at random. Main conclusions The Mediterranean MPA system falls short in meeting conservation targets for coastal fish taxonomic diversity, phylogenetic diversity and functional diversity. Mediterranean MPAs do not encompass more biodiversity than expected by chance. This study reveals multiple ongoing challenges and calls for regional collaboration for the extension of the Mediterranean system of MPAs to meet international commitments and reduce the ongoing loss of marine biodiversity.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue en Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1472-4642 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1254  
Lien permanent pour cet enregistrement
 

 
Auteur Mannocci, L.; Roberts, J.J.; Pedersen, E.J.; Halpin, P.N. doi  openurl
  Titre Geographical differences in habitat relationships of cetaceans across an ocean basin Type Article scientifique
  Année 2020 Publication (down) Revue Abrégée Ecography  
  Volume Numéro Pages  
  Mots-Clés associations; atlantic; conservation; distribution models; diversity; environmental predictors; geographical variation; habitat relationships; highly mobile marine species; marine mammals; North Atlantic Ocean; populations; predator; species distribution modeling; temperature; whales  
  Résumé The distributions of highly mobile marine species such as cetaceans are increasingly modeled at basin scale by combining data from multiple regions. However, these basin-wide models often overlook geographical variations in species habitat relationships between regions. We tested for geographical variations in habitat relationships for a suite of cetacean taxa between the two sides of the North Atlantic basin. Using cetacean visual survey data and remote sensing data from the western and eastern basin in summer, we related the probability of presence of twelve cetacean taxa from three guilds to seafloor depth, sea surface temperature and primary productivity. In a generalized additive model framework, we fitted 1) basin-wide (BW) models, assuming a single global relationship, 2) region-specific intercepts (RI) models, assuming relationships with the same shape in both regions, but allowing a region-specific intercept and 3) region-specific shape (RS) models, assuming relationships with different shapes between regions. RS models mostly yielded significantly better fits than BW models, indicating cetacean occurrences were better modeled with region-specific than with global relationships. The better fits of RS models over RI models further provided statistical evidence for differences in the shapes of region-specific relationships. Baleen whales showed striking differences in both the shapes of relationships and their mean presence probabilities between regions. Deep diving whales and delphinoids showed contrasting relationships between regions with few exceptions (e.g. non-statistically different shapes of region-specific relationships for harbor porpoise and beaked whales with depth). Our findings stress the need to account for geographical differences in habitat relationships between regions when modeling species distributions from combined data at the basin scale. Our proposed hypotheses offer a roadmap for understanding why habitat relationships may geographically vary in cetaceans and other highly mobile marine species.  
  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 0906-7590 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000531110000001 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2792  
Lien permanent pour cet enregistrement
 

 
Auteur Lorrain, A.; Graham, B.S.; Popp, B.N.; Allain, V.; Olson, R.J.; Hunt, B.P.V.; Potier, M.; Fry, B.; Galván-Magaña, F.; Menkes, C.E.R.; Kaehler, S.; Ménard, F. url  doi
openurl 
  Titre Nitrogen isotopic baselines and implications for estimating foraging habitat and trophic position of yellowfin tuna in the Indian and Pacific Oceans Type Article scientifique
  Année 2015 Publication (down) Revue Abrégée Deep Sea Research Part II: Topical Studies in Oceanography  
  Volume Numéro Pages 188-198  
  Mots-Clés Aa-Csia; Amino acids; Barnacles; Lepas anatifera; Marine top predators; Nitrogen stable isotopes; Pom; Thunnus albacares  
  Résumé Assessment of isotopic compositions at the base of food webs is a prerequisite for using stable isotope analysis to assess foraging locations and trophic positions of marine organisms. Our study represents a unique application of stable-isotope analyses across multiple trophic levels (primary producer, primary consumer and tertiary consumer) and over a large spatial scale in two pelagic marine ecosystems. We found that δ15N values of particulate organic matter (POM), barnacles and phenylalanine from the muscle tissue of yellowfin tuna all showed similar spatial patterns. This consistency suggests that isotopic analysis of any of these can provide a reasonable proxy for isotopic variability at the base of the food web. Secondly, variations in the δ15N values of yellowfin tuna bulk-muscle tissues paralleled the spatial trends observed in all of these isotopic baseline proxies. Variation in isotopic composition at the base of the food web, rather than differences in tuna diet, explained the 11‰ variability observed in the bulk-tissue δ15N values of yellowfin tuna. Evaluating the trophic position of yellowfin tuna using amino-acid isotopic compositions across the western Indian and equatorial Pacific Oceans strongly suggests these tuna occupy similar trophic positions, albeit absolute trophic positions estimated by this method were lower than expected. This study reinforces the importance of considering isotopic baseline variability for diet studies, and provides new insights into methods that can be applied to generate nitrogen isoscapes for worldwide comparisons of top predators in marine ecosystems.  
  Adresse  
  Auteur institutionnel Thèse  
  Editeur Lieu de Publication Éditeur  
  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Impacts of climate on marine top predators Titre de collection Abrégé  
  Volume de collection 113 Numéro de collection Edition  
  ISSN 0967-0645 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1257  
Lien permanent pour cet enregistrement
 

 
Auteur Alfonso, S.; Sadoul, B.; Cousin, X.; Begout, M.-L. doi  openurl
  Titre Spatial distribution and activity patterns as welfare indicators in response to water quality changes in European sea bass, Dicentrarchus labrax Type Article scientifique
  Année 2020 Publication (down) Revue Abrégée Appl. Anim. Behav. Sci.  
  Volume 226 Numéro Pages Unsp-104974  
  Mots-Clés ammonia toxicity; atlantic salmon; avoidance-behavior; behavioral-responses; Behaviour; current issues; Fish; hyperoxia; hypoxia tolerance; marine fish; rainbow-trout; Stress; stress-response; Water quality; Welfare  
  Résumé In aquaculture, fish are exposed to unavoidable stressors that can be detrimental for their health and welfare. However, welfare in farmed fish can be difficult to assess, and, so far, no standardized test has been universally accepted as a welfare indicator. This work contributes to the establishment of behavioural welfare indicators in a marine teleost in response to different water quality acute stressors. Groups of ten fish were exposed to high Total Ammonia Nitrogen concentration (High TAN, 18 mg.L-1), Hyperoxia (200 % O-2 saturation), Hypoxia (20 % O-2 saturation), or control water quality (100% O-2 saturation and TAN < 2.5 mg.L-1) over 1 hour. Fish were then transferred in a novel environment for a group behaviour test under the same water quality conditions over 2 hours. Videos were recorded to assess thigmotaxis, activity and group cohesion. After this challenge, plasma cortisol concentration was measured in a subsample, while individual behavioural response was measured in the other fish using novel tank diving test. Prior to this study, the novel tank diving test was validated as a behavioural challenge indicative of anxiety state, by using nicotine as anxiolytic drug. Overall, all stress conditions induced a decrease in activity and thigmotaxis and changes in group cohesion while only fish exposed to Hypoxia and High TAN conditions displayed elevated plasma cortisol concentrations. In post-stress condition, activity was still affected but normal behaviour was recovered within the 25 minutes of the test duration. Our work suggests that the activity, thigmotaxis and group cohesion are good behavioural indicators of exposure to degraded water quality, and could be used as standardized measures to assess fish welfare.  
  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 0168-1591 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000531095400002 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2794  
Lien permanent pour cet enregistrement
 

 
Auteur Shin, Y.-J.; Houle, J.E.; Akoglu, E.; Blanchard, J.L.; Bundy, A.; Coll, M.; Demarcq, H.; Fu, C.; Fulton, E.A.; Heymans, J.J.; Salihoglu, B.; Shannon, L.; Sporcic, M.; Velez, L. url  doi
openurl 
  Titre The specificity of marine ecological indicators to fishing in the face of environmental change: A multi-model evaluation Type Article scientifique
  Année 2018 Publication (down) Revue Abrégée Ecological Indicators  
  Volume 89 Numéro Pages 317-326  
  Mots-Clés ecosystem approach to fisheries; Indicator performance; Marine ecosystem models; Multi-model evaluation; Scenarios; Signal-to-noise ratio  
  Résumé Ecological indicators are widely used to characterise ecosystem health. In the marine environment, indicators have been developed to assess the ecosystem effects of fishing to support an ecosystem approach to fisheries. However, very little work on the performance and robustness of ecological indicators has been carried out. An important aspect of robustness is that indicators should respond specifically to changes in the pressures they are designed to detect (e.g. fishing) rather than changes in other drivers (e.g. environment). We adopted a multi-model approach to compare and test the specificity of commonly used ecological indicators to capture fishing effects in the presence of environmental change and under different fishing strategies. We tested specificity in the presence of two types of environmental change: “random”, representing interannual climate variability and “directional”, representing climate change. We used phytoplankton biomass as a proxy of the environmental conditions, as this driver was comparable across all ecosystem models, then applied a signal-to-noise ratio analysis to test the specificity of indicators with random environmental change. For directional change, we used mean gradients to apportion the quantity of change in the indicators due to fishing and the environment. We found that depending on the fishing strategy and environmental change, ecological indicators could range from high to low specificity to fishing. As expected, the specificity of indicators to fishing almost always decreased as environmental variability increased. In 55–76% of the scenarios run with directional change in phytoplankton biomass across fishing strategies and ecosystem models, indicators were significantly more responsive to changes in fishing than to changes in phytoplankton biomass. This important result makes the tested ecological indicators good candidates to support fisheries management in a changing environment. Among the indicators, the catch over biomass ratio was most often the most specific indicator to fishing, whereas mean length was most often the most sensitive to change in phytoplankton biomass. However, the responses of indicators were highly variable depending on the ecosystem and fishing strategy under consideration. We therefore recommend that indicators should be tested in the particular ecosystem before they are used for monitoring and management purposes.  
  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 1470-160x ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2285  
Lien permanent pour cet enregistrement
Tout Sélectionner    Désélectionner
 |   | 
Détails
   print

Save Citations:
Export Records: