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Auteur Lett, C.; Barrier, N.; Bahlali, M. doi  openurl
  Titre Converging approaches for modeling the dispersal of propagules in air and sea Type Article scientifique
  Année 2020 Publication Revue Abrégée Ecol. Model.  
  Volume 415 Numéro Pages 108858  
  Mots-Clés Aerial dispersal; Aquatic dispersal; Atmospheric dispersal; Biophysical model; Eulerian model; Lagrangian model; larval dispersal; long-distance dispersal; Marine dispersal; Oceanic dispersal; particle trajectories; population connectivity; Propagule dispersal; reef fish; schooling behavior; seed dispersal; spatially explicit; terrestrial ecology; understanding recruitment; Wind dispersal  
  Résumé Terrestrial plants seeds, spores and pollen are often dispersed by wind. Likewise, most eggs and larvae of marine organisms are dispersed by oceanic currents. It was historically believed that the spatial scale at which dispersal occurs was orders of magnitude smaller for plants than for fish. However, recent empirical estimates of seed and larval dispersal suggest that these dispersal scales are more alike than previously thought. The modeling approaches used to simulate aerial and aquatic dispersal are also converging. Similar biophysical models are developed, in which outputs of Eulerian models simulating the main physical forcing mechanism (wind or currents) are used as inputs to Lagrangian models that include biological components (such as seed terminal velocity or larval vertical migration). These biophysical models are then used to simulate trajectories of the biological entities (seeds, larvae) in three dimensions. We reflect on these converging trends by first putting them into an historical perspective, and then by comparing the physical and biological processes represented in marine larva vs. terrestrial seed dispersal models, the data used for the models output corroboration, and the tools available to perform simulations. We conclude that this convergence offers the opportunity to bridge the gap between two scientific communities which are currently largely disconnected. More broadly, we also see our comparison across systems as a useful way to strengthen the links between aquatic and terrestrial ecology by sharing knowledge, methods, tools, and concepts.  
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  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 0304-3800 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000501415400006 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection (down) 2706  
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Auteur Cox, S.L.; Authier, M.; Orgeret, F.; Weimerskirch, H.; Guinet, C. doi  openurl
  Titre High mortality rates in a juvenile free-ranging marine predator and links to dive and forage ability Type Article scientifique
  Année 2020 Publication Revue Abrégée Ecol. Evol.  
  Volume 10 Numéro 1 Pages 410-430  
  Mots-Clés antarctic fur seals; behavior; bio-logging; body condition; early life; foraging ecology; juvenile mortality; Mirounga leonina; mirounga-leonina; population; regularization paths; southern elephant seal; southern elephant seals; survival; survival analyses; variable selection; weaning mass  
  Résumé High juvenile mortality rates are typical of many long-lived marine vertebrate predators. Insufficient development in dive and forage ability is considered a key driver of this. However, direct links to survival outcome are sparse, particularly in free-ranging marine animals that may not return to land. In this study, we conduct exploratory investigations toward early mortality in juvenile southern elephant seals Mirounga leonina. Twenty postweaning pups were equipped with (a) a new-generation satellite relay data tag, capable of remotely transmitting fine-scale behavioral movements from accelerometers, and (b) a location transmitting only tag (so that mortality events could be distinguished from device failures). Individuals were followed during their first trip at sea (until mortality or return to land). Two analyses were conducted. First, the behavioral movements and encountered environmental conditions of nonsurviving pups were individually compared to temporally concurrent observations from grouped survivors. Second, common causes of mortality were investigated using Cox's proportional hazard regression and penalized shrinkage techniques. Nine individuals died (two females and seven males) and 11 survived (eight females and three males). All but one individual died before the return phase of their first trip at sea, and all but one were negatively buoyant. Causes of death were variable, although common factors included increased horizontal travel speeds and distances, decreased development in dive and forage ability, and habitat type visited (lower sea surface temperatures and decreased total [eddy] kinetic energy). For long-lived marine vertebrate predators, such as the southern elephant seal, the first few months of life following independence represent a critical period, when small deviations in behavior from the norm appear sufficient to increase mortality risk. Survival rates may subsequently be particularly vulnerable to changes in climate and environment, which will have concomitant consequences on the demography and dynamics of populations.  
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  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 2045-7758 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000502011200001 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection (down) 2698  
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Auteur Lagarde, F.; Fiandrino, A.; Ubertini, M.; d'Orbcastel, E.R.; Mortreux, S.; Chiantella, C.; Bec, B.; Bonnet, D.; Roques, C.; Bernard, I.; Richard, M.; Guyondet, T.; Pouvreau, S.; Lett, C. url  doi
openurl 
  Titre Duality of trophic supply and hydrodynamic connectivity drives spatial patterns of Pacific oyster recruitment Type Article scientifique
  Année 2019 Publication Revue Abrégée Marine Ecology Progress Series  
  Volume 632 Numéro Pages 81-100  
  Mots-Clés Coastal lagoon; Connectivity; Crassostrea gigas; Larval ecology; Oligotrophication; Recruitment; Settlement; Spatial patterns  
  Résumé The recent discovery of Pacific oyster Crassostrea gigas (also known as Magallana gigas) spatfields in a Mediterranean lagoon intensely exploited for shellfish farming (Thau lagoon) revealed significant contrasts in spatial patterns of recruitment. We evaluated the processes that drive spatial patterns in oyster recruitment by comparing observed recruitment, simulated hydrodynamic connectivity and ecological variables. We hypothesized that spatial variability of recruitment depends on (1) hydrodynamic connectivity and (2) the ecology of the larval supply, settlement, metamorphosis, survival and biotic environmental parameters. We assessed recruitment at 6-8 experimental sites by larval sampling and spat collection inside and outside oyster farming areas and on an east-west gradient, from 2012-2014. Hydrodynamic connectivity was simulated using a numerical 3D transport model assessed with a Eulerian indicator. The supply of large umbo larvae did not differ significantly inside and outside oyster farming areas, whereas the supply of pediveligers to sites outside shellfish farms was structured by hydrodynamic connectivity. Inside shellfish farming zones, unfavorable conditions due to trophic competition with filter-feeders jeopardized their settlement. In this case, our results suggest loss of settlement competence by oyster larvae. This confirms our hypothesis of top-down trophic control by the oysters inside farming zones of Thau lagoon in summer that fails to meet the ecological requirements of these areas as oyster nurseries. Knowledge of oyster dispersal, connectivity and recruitment in coastal lagoons will help local development of sustainable natural spat collection. On a global scale, our method could be transposed to other basins or used for other species such as mussels, clams or scallops, to better understand the spatial patterns of bivalve recruitment. Management of the oyster industry based on natural spat collection will help develop a sustainable activity, based on locally adapted oyster strains but also by reducing the risks of transferring pathogens between basins and the global carbon footprint of this industry.  
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  Volume de collection Numéro de collection Edition  
  ISSN 0171-8630, 1616-1599 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection (down) 2673  
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Auteur McLean, M.; Mouillot, D.; Villeger, S.; Graham, N.A.J.; Auber, A. doi  openurl
  Titre Interspecific differences in environmental response blur trait dynamics in classic statistical analyses Type Article scientifique
  Année 2019 Publication Revue Abrégée Mar. Biol.  
  Volume 166 Numéro 12 Pages 152  
  Mots-Clés climate-change; community composition; ecology; framework; functional diversity; impact; rules  
  Résumé Trait-based ecology strives to better understand how species, through their bio-ecological traits, respond to environmental changes, and influence ecosystem functioning. Identifying which traits are most responsive to environmental changes can provide insight for understanding community structuring and developing sustainable management practices. However, misinterpretations are possible, because standard statistical methods (e.g., principal component analysis and linear regression) for identifying and ranking the responses of different traits to environmental changes ignore interspecific differences. Here, using both artificial data and real-world examples from marine fish communities, we show how considering species-specific responses can lead to drastically different results than standard community-level methods. By demonstrating the potential impacts of interspecific differences on trait dynamics, we illuminate a major, yet rarely discussed issue, highlighting how analytical misinterpretations can confound our basic understanding of trait responses, which could have important consequences for biodiversity conservation.  
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  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 0025-3162 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000496131000001 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection (down) 2660  
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Auteur Soissons, L.M.; van Katwijk, M.M.; Li, B.; Han, Q.; Ysebaert, T.; Herman, P.M.J.; Bouma, T.J. doi  openurl
  Titre Ecosystem engineering creates a new path to resilience in plants with contrasting growth strategies Type Article scientifique
  Année 2019 Publication Revue Abrégée Oecologia  
  Volume 191 Numéro 4 Pages 1015-1024  
  Mots-Clés competition; dynamics; ecology; eelgrass zostera-marina; exposure; indicators; organisms; Recovery from disturbance; Resistance to stress; Seagrass; seagrass beds; sediment-nutrient; stiffness; Sulphide intrusion  
  Résumé Plant species can be characterized by different growth strategies related to their inherent growth and recovery rates, which shape their responses to stress and disturbance. Ecosystem engineering, however, offers an alternative way to cope with stress: modifying the environment may reduce stress levels. Using an experimental study on two seagrass species with contrasting traits, the slow-growing Zostera marina vs. the fast-growing Zostera japonica, we explored how growth strategies versus ecosystem engineering may affect their resistance to stress (i.e. addition of organic material) and recovery from disturbance (i.e. removal of above-ground biomass). Ecosystem engineering was assessed by measuring sulphide levels in the sediment porewater, as seagrass plants can keep sulphide levels low by aerating the rhizosphere. Consistent with predictions, we observed that the fast-growing species had a high capacity to recover from disturbance. It was also more resistant to stress and still able to maintain high standing stock with increasing stress levels because of its ecosystem engineering capacity. The slow-growing species was not able to maintain its standing stock under stress, which we ascribe to a weak capacity for ecosystem engineering regarding this particular stress. Overall, our study suggests that the combination of low-cost investment in tissues with ecosystem engineering to alleviate stress creates a new path in the growth trade-off between investment in strong tissues or fast growth. It does so by being both fast in recovery and more resistant. As such low-cost ecosystem engineering may occur in more species, we argue that it should be considered in assessing plant resilience.  
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  Langue English Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 0029-8549 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000496412400025 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection (down) 2659  
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