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Auteur Thiebault, A.; Mullers, R.H.E.; Pistorius, P.A.; Tremblay, Y.
Titre Local enhancement in a seabird: reaction distances and foraging consequence of predator aggregations Type Article scientifique
Année 2014 Publication Revue Abrégée Behavioral Ecology
Volume 25 Numéro 6 Pages (down) 1302-1310
Mots-Clés camera; foraging cues; gannet; Gps; group hunting; network foraging; prey detection; social information.
Résumé Seabirds foraging on pelagic fish develop behavioral strategies specifically adapted to locate inconspicuous prey that are aggregated in spatially dynamic patches. In the marine environment, they may use various mechanisms to detect cues of prey availability. The aggregation of predators at a patch of food is a particularly obvious cue to locate prey, a mechanism known as local enhancement. Pioneering studies described the formation of foraging groups at sea, showing that seabirds are attracted to feeding conspecifics. Improved foraging success due to local enhancement has been suggested from modeling studies, but no direct validation of these results exists. We deployed video cameras concomitantly with GPS loggers on Cape gannets to study the behavioral responses of equipped birds to the aggregation of predators at food patches. We showed that the reaction distances of equipped birds increased with the size of an aggregation, demonstrating that predator aggregations enhance food detectability for foragers. For small aggregations (<50 gannets), reaction distances were mostly less than 10 km, and they increased up to almost 40 km for larger aggregations (100–150 gannets). In addition, we showed that the number and frequency of dives increased with the number of conspecifics aggregated, up to a threshold. The predator aggregations on a patch of food could, therefore, not only inform about the presence of prey but also entail information about foraging conditions. From direct observations on the various components involved, our study provides justification of the use and advantages of local enhancement in foraging seabirds.
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ISSN 1045-2249, 1465-7279 ISBN Médium
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Auteur Avadi, A.; Freon, P.; Quispe, I.
Titre Environmental assessment of Peruvian anchoveta food products : is less refined better ? Type Article scientifique
Année 2014 Publication Revue Abrégée International Journal of Life Cycle Assessment
Volume 19 Numéro 6 Pages (down) 1276-1293
Mots-Clés Cold chain; Engraulis ringens; Frozen, canned and cured fish; Life cycle assessment; Peru
Résumé Life cycle assessments (LCAs) of various anchovy (anchoveta) direct human consumption products processed in Peru were carried out, to evaluate their relative environmental performance as alternative products to enhance nutrition of communities with low access to fish products in the country. LCA was carried out for fresh, frozen, canned, salted and cured anchoveta products, both at plant gate and featuring local and national distribution over non-refrigerated, chilled and fully refrigerated distribution chain. The functional unit used was 1 kg of fish in the final product. Results demonstrate that, in environmental terms, more-refined products (cured and canned anchoveta products) represent a much higher burden than less- refined products (fresh, frozen and salted). Although this is a likely result, the magnitude of this difference (4 to 27 times when expressed as an environmental single score) is higher than expected and had not been quantified before for salted and cured products, as far as we know. This difference is mainly due to differences in energy consumption between types of products. Furthermore, cured and salted products feature larger biotic resource use, when calculated based on the whole fish equivalent, due to higher processing losses/discards. The relevance of taking into account the different transportation and storage needs is highlighted. For those products requiring refrigerated transportation and storage, over a national distribution chain, those activities increase the overall environmental impacts of the products by 55 % (fresh chilled) to 67 % (frozen). However, such an increase does not worsen the environmental performance of fresh and frozen products in comparison to the energy-intensive canned and cured products. It is concluded that a more sustainability-oriented analysis, including the social and economic pillars of sustainability, is required towards decision-making involving promotion of either product for addressing nutritional deficiencies in Peru.
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ISSN 0948-3349 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1144
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Auteur Patino, J.; Weigelt, P.; Guilhaumon, F.; Kreft, H.; Triantis, K.A.; Naranjo-Cigala, A.; Solymos, P.; Vanderpoorten, A.
Titre Differences in species-area relationships among the major lineages of land plants: a macroecological perspective Type Article scientifique
Année 2014 Publication Revue Abrégée Global Ecology and Biogeography
Volume 23 Numéro 11 Pages (down) 1275-1283
Mots-Clés biology; bryophytes; Carrying capacity; cloning; data; Dispersal ability; et-al.; geographical; isolation; long-distance dispersal; maximum-entropy; pteridophytes; range sizes; richness; scale; species-area relationship; species richness; species turnover; spermatophytes; spore-producing plants; universality
Résumé AimAlthough the increase in species richness with increasing area is considered one of the few laws in ecology, the role of environmental and taxon-specific features in shaping species-area relationships (SARs) remains controversial. Using 421 land-plant floras covering continents, continental islands and oceanic islands, we investigate whether variations in SAR parameters can be interpreted in terms of differences among lineages in speciation mode and dispersal capacities (TAXON), or of geological history and geographical isolation between continents and islands (GEO). LocationGlobal. MethodsLinear mixed-effects models describing variation in SARs, depending on the factors GEO and TAXON and controlling for differences between realms (REALM) and biomes (BIOME). ResultsThe best random-effect structure included both random slopes and random intercepts for GEO, TAXON, REALM and BIOME. This accounted for 77% of the total variation in species richness, substantially more than the 27% statistically explained by the model with fixed effects only (i.e. the simple SAR). The slopes of the SARs were higher for oceanic islands than for continental islands and continents, and higher in spermatophytes than in pteridophytes and bryophytes. The intercepts largely exhibited the reverse trend. TAXON was included in best-fit models restricted to oceanic and continental islands, but not continents. Analysing each plant lineage separately, the intercept of GEO was only included in the random structure of spermatophytes. Main conclusionsSAR parameters varied considerably depending on geological history and taxon-specific traits. Such differences in SARs among land plants challenge the neutral theory that the accumulation of species richness on islands is controlled exclusively by extrinsic factors. Taxon-specific differences in SARs were, however, confounded by interactions with geological history and geographical isolation. This highlights the importance of applying integrative frameworks that take both environmental context and taxonomic idiosyncrasies into account in SAR analyses.
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ISSN 1466-822x ISBN Médium
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Notes <p>ISI Document Delivery No.: AR6ZU<br/>Times Cited: 2<br/>Cited Reference Count: 59<br/>Patino, Jairo Weigelt, Patrick Guilhaumon, Francois Kreft, Holger Triantis, Kostas A. Naranjo-Cigala, Agustin Solymos, Peter Vanderpoorten, Alain<br/>Belgian Funds for Scientific Research (FNRS) [1.5036.11, 2.4557.11]; University of Liege [C 11/32]; European Union [ES-TAF-2553, SE-TAF-1361, GB-TAF-1801]; DFG Initiative of Excellence via the Free Floater programme at the University of Gottingen<br/>Many thanks are given to Richard Field, David Currie, Silvia C. Aranda, Joaquin Hortal and three referees for their constructive comments on the manuscript. We are particularly grateful to S. Robbert Gradstein for providing unpublished data from Hawaii, Juana M. Gonzalez-Mancebo for making available unpublished data for the Canarian islets, and Martin Turjak for drawings. J.P and A.V. gratefully acknowledge financial support from the Belgian Funds for Scientific Research (FNRS) (grants 1.5036.11 and 2.4557.11) and the University of Liege (grant C 11/32); J.P. also acknowledges support from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement ES-TAF-2553, SE-TAF-1361 and GB-TAF-1801 (SYNTHESYS); P.W and H.K. were funded by the DFG Initiative of Excellence via the Free Floater programme at the University of Gottingen.<br/>Wiley-blackwell<br/>Hoboken</p> Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 1171
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Auteur Li, X.; Blancheton, J.-P.; Liu, Y.; Triplet, S.; Michaud, L.
Titre Effect of oxidation-reduction potential on performance of European sea bass (Dicentrarchus labrax) in recirculating aquaculture systems Type Article scientifique
Année 2014 Publication Revue Abrégée Aquaculture International
Volume 22 Numéro 4 Pages (down) 1263-1282
Mots-Clés culture-system; disinfection; european sea bass; Orp; ozonated; Ozone; performance; Ras; responses; rock lobster; salinity; seawater; sublethal exposure; trout oncorhynchus-mykiss; water-quality
Résumé The direct impact of oxidation-reduction potential (ORP) on fish welfare and water quality in marine recirculating aquaculture systems (RAS) is poorly documented. In this study, the effects of the fish size (S-1, S-2, S-3) and ORP level (normal, four successive levels) on the performance of European sea bass (Dicentrarchus labrax) were investigated. Three size fish were distributed into two RAS (RAS and RAS O-3). Ozone was injected into RAS O-3 to increase the ORP level. The ORP was stabilized to four successive levels: 260-300, 300-320, 320-350, and 300-320 mV in fish tanks during four periods (P1-4). At the last day of each period, the hematological parameters, plasma protein and mortality of sea bass were analyzed. Two-way ANOVA revealed that several hematological parameters, including pH, hematocrit, concentrations of oxygen, carbon dioxide, glucose (Glu), ionized calcium, kalium, and hemoglobin, were significantly influenced by the increased ORP levels over the experimental period. The alteration in blood Glu and plasma protein concentration showed that ORP around 300-320 mV started to stress sea bass. Once the ORP exceeded 320 mV in the tanks during the P-3 period, mortality occurred even when total residual oxidants/ozone-produced oxidants was only 0.03-0.05 mg L-1 in the fish tanks. At the same time, plasma protein decreased notably due to appetite depression. After the decrease in ORP during the P-4 period, mortality continued. In conclusion, the results strongly suggest that for European sea bass in RAS, the ORP should not exceed 320 mV in the tanks. Once ozonation damaged fish, the effect seemed to be irreversible. However, how ORP affected related hematological parameters still need the further investigations.
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ISSN 0967-6120 ISBN Médium
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Notes <p>ISI Document Delivery No.: AL4MD<br/>Times Cited: 1<br/>Cited Reference Count: 35<br/>Li, Xian Blancheton, Jean-Paul Liu, Ying Triplet, Sebastien Michaud, Luigi<br/>National Natural Science Foundation of China [41306152]; National Science and Technology Support Program [2011BAD13B04]<br/>The authors would thank all the participants from the Ifremer Palavas station: Cyrille Przybyla, Myriam Callier, and Thibault Geoffroy for their contribution to the experiment and analyses. This work was supported by the National Natural Science Foundation of China (Grant No. 41306152) and National Science and Technology Support Program (Grant No. 2011BAD13B04).<br/>Springer<br/>Dordrecht</p> Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 1168
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Auteur LE MAHO, Y.; WHITTINGTON, J.D.; HANUISE, N.; PEREIRA, L.; BOUREAU, M.; BRUCKER, M.; CHATELAIN, N.; COURTECUISSE, J.; CRENNER, F.; FRIESS, B.; GROSBELLET, E.; KERNALEGUEN, L.; OLIVER, F.; SARAUX, C.; VETTER, N.; VIBLANC, V.A.; THIERRY, B.; TREMBLAY, P.; GROSCOLAS, R.; LE BOHEC, C.
Titre Rovers minimize human disturbance in research on wild animals Type Article scientifique
Année 2014 Publication Revue Abrégée Nature Methods
Volume 11 Numéro 12 Pages (down) 1242-1244
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Résumé Investigating wild animals while minimizing human disturbance remains an important methodological challenge. When approached by a remote-operated vehicle (rover) which can be equipped to make radio-frequency identifications, wild penguins had significantly lower and shorter stress responses (determined by heart rate and behavior) than when approached by humans. Upon immobilization, the rover-unlike humans-did not disorganize colony structure, and stress rapidly ceased. Thus, rovers can reduce human disturbance of wild animals and the resulting scientific bias.
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ISSN 1548-7091 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1128
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