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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 (up) 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 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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ISSN 1365-2699 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1538
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Auteur Colin, N.; Villeger, S.; Wilkes, M.; de Sostoa, A.; Maceda-Veiga, A.
Titre Functional diversity measures revealed impacts of non-native species and habitat degradation on species-poor freshwater fish assemblages Type Article scientifique
Année 2018 Publication (up) Revue Abrégée Sci. Total Environ.
Volume 625 Numéro Pages 861-871
Mots-Clés biodiversity; ecosystems; community; life-history traits; Non-native species; 4th-corner problem; Functional diversity; Fish assemblages; Biomonitoring; ecological quality; flow regime; Human disturbance; mediterranean rivers; Mediterranean rivers; stream; traits-environment relationships
Résumé Trail-based ecology has been developed for decades lo infer ecosystem responses to stressors based on the functional structure of communities, yet its value in species-poor systems is largely unknown. Here, we used an extensive clataset in a Spanish region highly prone to non-native fish invasions (15 catchments, N 389 sites) to assess for the first time how species-poor communities respond to large-scale environmental gradients using a taxonomic and functional trait-based approach in riverine fish. We examined total species richness and three functional trait-based indices available when many sites have <= 3 species (specialization, FSpe; onginaliy, FOri and entropy, FEnt). We assessed the responses of these taxonomic and functional indices along gradients of altitude, water pollution, physical habitat degradation and non-native fish biomass. Whilst species richness was relatively sensitive to spatial effects, functional diversity indices were responsive across natural and anthropogenic gradients. All four diversity measures declined with altitude but this decline was modulated by physical habitat degradation (richness, FSpe and FEnt) and the non-native total fish biomass ratio (FSpe and FOri) in ways that varied between indices. Furthermore, FSpe and FOri were significantly correlated with Total Nitrogen. Non-native fish were a major component of the taxonomic and functional structure of fish communities, raising concerns about potential misdiagnosis between invaded and environmentally-degraded river reaches. Such misdiagnosis was evident in a regional fish index widely used in official monitoring programs. We recommend the application of FSpe and FOri to extensive clatasets from monitoring programs in order to generate valuable cross-system information about the impacts of non-native species and habitat degradation, even in species-poor systems. Scoring non-native species apart from habitat degradation in the indices used to determine ecosystem health is essential to develop better management strategies. (C) 2013 Elsevier B.V. All rights reserved.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0048-9697 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2309
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Auteur Benedetti, F.; Vogt, M.; Righetti, D.; Guilhaumon, F.; Ayata, S.-D.
Titre Do functional groups of planktonic copepods differ in their ecological niches? Type Article scientifique
Année 2018 Publication (up) Revue Abrégée J. Biogeogr.
Volume 45 Numéro 3 Pages 604-616
Mots-Clés climate-change; copepods; species distribution models; north-atlantic; calanus-finmarchicus; mediterranean sea; environmental niche; functional groups; lipid pump; marine ecosystem; oithona-similis; pseudo-absences; trait biogeography; zooplankton; zooplankton fecal pellets
Résumé Aim: To assess the degree of overlap between the environmental niches of marine planktonic copepods and test if the distribution of copepod functional groups differs across environmental gradients. Location: The Mediterranean Sea. Methods: Functional groups were defined based on clustering of functional traits in 106 marine copepod species using a multivariate ordination analysis. Functional traits included maximum body length, feeding mode, spawning strategy and trophic group. Simultaneously, the global distribution of the species was used to model their environmental niches with six environmental variables. For each of these predictors, four niche parameters were derived from the univariate response curve of each species to summarise their environmental preferences and ordinate the species in niche space through a PCA. Finally, the differences in the position in niche space of functional groups were tested with variance analysis. Results: We identified seven copepod functional groups with different distributions along the environmental gradients covered by our study. While carnivorous functional groups were affiliated with oligotrophic and tropical conditions, large and small current-feeding herbivores are associated with colder, more seasonally varying and productive conditions. Small cruising detritivores and other small current-feeding herbivores were not affiliated with specific conditions as their constituting species were scattered in niche space. Main conclusions: Since copepod functional groups occupy distinct ecological niches, ecosystem processes related to these groups are expected to vary across environmental gradients. Conditions favouring large current-feeding herbivores should allow for enhanced fluxes of energy and nutrients through Mediterranean Sea ecosystems, while such fluxes should be weakened where large carnivores and small passive ambush-feeding copepods dominate. Our study supports the development of trait-based zooplankton functional groups in marine ecosystem models.
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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 0305-0270 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2311
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Auteur Calo, A.; Lett, C.; Mourre, B.; Perez-Ruzafa, A.; Antonio Garcia-Charton, J.
Titre Use of Lagrangian simulations to hindcast the geographical position of propagule release zones in a Mediterranean coastal fish Type Article scientifique
Année 2018 Publication (up) Revue Abrégée Mar. Environ. Res.
Volume 134 Numéro Pages 16-27
Mots-Clés circulation; Mediterranean Sea; sea; dispersal; larval; habitat; marine protected areas; recruitment; variability; population connectivity; Dispersal distance; Lagrangian simulations; mesoscale eddies; Propagule release zones; Sea bream
Résumé The study of organism dispersal is fundamental for elucidating patterns of connectivity between populations, thus crucial for the design of effective protection and management strategies. This is especially challenging in the case of coastal fish, for which information on egg release zones (i.e. spawning grounds) is often lacking. Here we assessed the putative location of egg release zones of the saddled sea bream (Oblada melanura) along the southeastern coast of Spain in 2013. To this aim, we hindcasted propagule (egg and larva) dispersal using Lagrangian simulations, fed with species-specific information on early life history traits (ELTs), with two approaches: 1) back-tracking and 2) comparing settler distribution obtained from simulations to the analogous distribution resulting from otolith chemical analysis. Simulations were also used to assess which factors contributed the most to dispersal distances. Back-tracking simulations indicated that both the northern sector of the Murcia region and some traits of the North-African coast were hydrodynamically suitable to generate and drive the supply of larvae recorded along the coast of Murcia in 2013. With the second approach, based on the correlation between simulation outputs and field results (otolith chemical analysis), we found that the oceanographic characteristics of the study area could have determined the pattern of settler distribution recorded with otolith analysis in 2013 and inferred the geographical position of main O. melanura spawning grounds along the coast. Dispersal distance was found to be significantly affected by the geographical position of propagule release zones. The combination of methods used was the first attempt to assess the geographical position of propagule release zones in the Mediterranean Sea for O. melanura, and can represent a valuable approach for elucidating dispersal and connectivity patterns in other coastal species.
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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 0141-1136 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2313
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Auteur Deininger, A.; Faithfull, C.L.; Lange, K.; Bayer, T.; Vidussi, F.; Liess, A.
Titre Simulated terrestrial runoff triggered a phytoplankton succession and changed seston stoichiometry in coastal lagoon mesocosms Type Article scientifique
Année 2016 Publication (up) Revue Abrégée Mar. Environ. Res.
Volume 119 Numéro Pages 40-50
Mots-Clés climate change; communities; community composition; Diatoms; dynamics; ecosystems; events; food-web; growth; Mediterranean; Mesocosm; Phytoplankton; plankton; productivity; river flash-flood; schelde; soil; Stoichiometry; Thau lagoon
Résumé Climate change scenarios predict intensified terrestrial storm runoff, providing coastal ecosystems with large nutrient pulses and increased turbidity, with unknown consequences for the phytoplankton community. We conducted a 12-day mesocosm experiment in the Mediterranean Thau Lagoon (France), adding soil (simulated runoff) and fish (different food webs) in a 2 x 2 full factorial design and monitored phytoplankton composition, shade adaptation and stoichiometry. Diatoms (Chaetoceros) increased fourfold immediately after soil addition, prymnesiophytes and dinoflagellates peaked after six- and 12 days, respectively. Soil induced no phytoplanlcton shade adaptation. Fish reduced the positive soil effect on dinoflagellates (Scripsiella, Glenodinium), and diatom abundance in general. Phytoplankton community composition drove seston stoichiometry. In conclusion, pulsed terrestrial runoff can cause rapid, low quality (high carbon: nutrient) diatom blooms. However, bloom duration may be short and reduced in magnitude by fish. Thus, climate change may shift shallow coastal ecosystems towards famine or feast dynamics. (C) 2016 Elsevier Ltd. All rights reserved.
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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 0141-1136 ISBN Médium
Région Expédition Conférence
Notes Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 2063
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