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Auteur PETHYBRIDGE, H.; ROOS, D.; LOIZEAU, V.; PECQUERIE, L.; BACHER, C.
Titre Responses of European anchovy vital rates and population growth to environmental fluctuations: An individual-based modeling approach Type Article scientifique
Année 2013 Publication Revue Abrégée Ecological Modelling
Volume 250 Numéro Pages 370-383
Mots-Clés Dynamic Energy Budget theory; Engraulis encrasicolus; Environmental variability; Fecundity; growth; NW Mediterranean Sea
Résumé (up) A size-structured, bioenergetics model was implemented to examine the effects of short-term environmental changes on European anchovy, Engraulis encrasicolus, in the North-western Mediterranean Sea. The model approach was based on Dynamic Energy Budget (DEB) theory and details the acquisition and allocation of energy (J d(-1)) during an organisms' full life-cycle. Model calibration was achieved using biometric data collected from the Gulf of Lions between 2002 and 2011. Bioenergetics simulations successfully captured ontogenetic and seasonal growth patterns, including active growth in spring/summer, loss of mass in autumn/winter and the timing and amplitude of multi-batch spawning events. Scenario analysis determined that vital rates (growth and fecundity) were highly sensitive to short-term environmental changes. The DEB model provided a robust foundation for the implementation of an individual-based population model (IBM) in which we used to test the responses of intrinsic and density-independent population growth rates (r) to observed and projected environmental variability. IBM projections estimate that r could be reduced by as much as 15% (relative to that estimated under mean conditions) due to either a 5% (0.8 degrees C) drop in temperature (due to a reduced spawning duration), a 18% (25 mg zooplankton m(-3)) depletion in food supply, a 30% increase in egg mortality rates, or with the phytoplankton bloom peaking 5 weeks earlier (in late-February/Winter). The sensitivity of r to short-term (1 year) and long-term (4-10 year) environmental changes were similar, highlighting the importance of first-year spawners. In its current form, the models presented here could be incorporated into spatially-explicit, higher-trophic (predator-prey and end-to-end ecosystem), larval-dispersal and toxicokinetic models or adapted to other short-lived foraging fish (clupeid) species. (C) 2012 Elsevier B.V. All rights reserved.
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ISSN 0304-3800 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 248
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Auteur Delpy, F.; Albouy-Boyer, S.; Pagano, M.; Thibault, D.; Blanchot, J.; Guilhaumon, F.; Molinero, J.C.; Bonnet, D.
Titre Identifying the drivers of abundance and size of the invasive ctenophore Mnemiopsis leidyi in Northwestern Mediterranean lagoons Type Article scientifique
Année 2016 Publication Revue Abrégée Marine Environmental Research
Volume 119 Numéro Pages 114-125
Mots-Clés Blooms; Driving factors; Gelatinous plankton; Invasive species; Mediterranean lagoons; Mnemiopsis leidyi
Résumé (up) Acknowledged as among the worst invasive marine species, Mnemiopsis leidyi has spread through European Seas since the mid-1980’s. Here we report a bimonthly survey conducted in 2010–11 in three lagoons (Bages-Sigean, Thau and Berre) and at two adjacent coastal stations (Sète and SOMLIT-Marseille) along the French Mediterranean coast. M. leidyi was present only in Berre and Bages-Sigean with maximum abundances observed in late summer. M. leidyi adults were present year round in Berre with the largest organisms (∼6 cm) observed in April. In Bages-Sigean, they occurred in sufficient abundance to be recorded by fishermen between August and November. Multiple linear regressions highlighted that abundance in both lagoons was mainly influenced by direct effects of salinity and chlorophyll-a, and temperature to a lesser extent. While M. leidyi has not yet been recorded in Thau, the lagoon is continually monitored to detect the potential establishment of M. leidyi.
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ISSN 0141-1136 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1554
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Auteur Navarro, J.; Cardador, L.; Fernández, Á.M.; Bellido, J.M.; Coll, M.
Titre Differences in the relative roles of environment, prey availability and human activity in the spatial distribution of two marine mesopredators living in highly exploited ecosystems Type Article scientifique
Année 2016 Publication Revue Abrégée J. Biogeogr.
Volume 43 Numéro 3 Pages 440-450
Mots-Clés deviance partitioning; elasmobranchs; environmental variables; human stressors; indicator species; marine biodiversity; Marine conservation; Mediterranean Sea; Raja asterias; Scyliorhinus canicula
Résumé (up) Aim Identifying the main factors affecting the spatial distribution of marine predators is essential in order to evaluate their distribution patterns, predict the potential impact of human activities on their populations and design accurate management actions. This information is also valuable from a more general management perspective, as marine predators are often considered indicators of habitat quality. In this context, we aimed to determine the degree to which environmental features, prey availability and human activities interact and influence spatial distribution of two marine mesopredator elasmobranchs, the small-spotted catshark (Scyliorhinus canicula) and the Mediterranean starry ray (Raja asterias), living in a highly human-exploited environment. Location Mediterranean Sea. Methods With information obtained from an extended experimental survey, we investigated the relative importance of environmental variables, prey availability and human activities on the spatial distribution of the abundance, biomass and occurrence rate of these marine mesopredators using deviance partitioning analyses. Results Our results revealed that environmental variables were the most important factors explaining the spatial distribution of Mediterranean starry ray, whereas small-spotted catshark distribution was also influenced by prey availability and human factors. From a management point of view, these findings suggest that Mediterranean starry ray could be a good candidate as an indicator species of demersal environmental quality. On the other hand, the distribution of the small-spotted catshark, which responds in an interactive and complex way to environment, prey availability and particular human activities, may be misleading as an environmental indicator. Main conclusions The spatial distribution of elasmobranchs in highly human-impacted marine areas can reflect the interactive and combined effects of multiple factors. To avoid misunderstandings, attention should be paid to statistical procedures allowing the separation of pure and joint contribution of the factors driving the observed spatial patterns.
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Langue en Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1365-2699 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1538
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Auteur Hattab, T.; Albouy, C.; Lasram, F.B.R.; Somot, S.; Le Loc'h, F.; Leprieur, F.
Titre Towards a better understanding of potential impacts of climate change on marine species distribution: a multiscale modelling approach Type Article scientifique
Année 2014 Publication Revue Abrégée Global Ecology and Biogeography
Volume 23 Numéro 12 Pages 1417-1429
Mots-Clés climate change; exploited species; habitat loss; hierarchical filtering; Mediterranean Sea; spatial scale; species distribution modelling
Résumé (up) Aim In this paper, we applied the concept of ‘hierarchical filters’ in community ecology to model marine species distribution at nested spatial scales. Location Global, Mediterranean Sea and the Gulf of Gabes (Tunisia). Methods We combined the predictions of bioclimatic envelope models (BEMs) and habitat models to assess the current distribution of 20 exploited marine species in the Gulf of Gabes. BEMs were first built at a global extent to account for the full range of climatic conditions encountered by a given species. Habitat models were then built using fine-grained habitat variables at the scale of the Gulf of Gabes. We also used this hierarchical filtering approach to project the future distribution of these species under both climate change (the A2 scenario implemented with the Mediterranean climatic model NEMOMED8) and habitat loss (the loss of Posidonia oceanica meadows) scenarios. Results The hierarchical filtering approach predicted current species geographical ranges to be on average 56% smaller than those predicted using the BEMs alone. This pattern was also observed under the climate change scenario. Combining the habitat loss and climate change scenarios indicated that the magnitude of range shifts due to climate change was larger than from the loss of P. oceanica meadows. Main conclusions Our findings emphasize that BEMs may overestimate current and future ranges of marine species if species–habitat relationships are not also considered. A hierarchical filtering approach that accounts for fine-grained habitat variables limits the uncertainty associated with model-based recommendations, thus ensuring their outputs remain applicable within the context of marine resource management.
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Volume de collection Numéro de collection Edition
ISSN 1466-8238 ISBN Médium
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Numéro d'Appel LL @ pixluser @ collection 391
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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.
Titre Representing taxonomic, phylogenetic and functional diversity: new challenges for Mediterranean marine-protected areas Type Article scientifique
Année 2015 Publication 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 (up) 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.
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Volume de collection Numéro de collection Edition
ISSN 1472-4642 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1254
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