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Auteur Triki, H.Z.; Laabir, M.; Lafabrie, C.; Malouche, D.; Bancon-Montigny, C.; Gonzalez, C.; Deidun, A.; Pringault, O.; Daly-Yahia, O.K.
Titre Do the levels of industrial pollutants influence the distribution and abundance of dinoflagellate cysts in the recently-deposited sediment of a Mediterranean coastal ecosystem? Type Article scientifique
Année 2017 Publication (up) Revue Abrégée Sci. Total Environ.
Volume 595 Numéro Pages 380-392
Mots-Clés alexandrium-pseudogonyaulax; bizerte lagoon tunisia; Dinocyst assemblage; environmental-factors; estuarine sediments; gonyaulax-polyedra; Interaction pollutants/cysts; Mediterranean Bizerte Lagoon; Organic/inorganic contaminants; polycyclic aromatic-hydrocarbons; recent marine-sediments; resting cysts; spatial distribution; spatial-distribution; surface sediments; Toxic/noxious species
Résumé We studied the relationships between sediment industrial pollutants concentrations, sediment characteristics and the dinoflagellate cyst abundance within a coastal lagoon by investigating a total of 55 sampling stations within the Bizerte lagoon, a highly anthropized Mediterranean ecosystem. The sediment of Bizerte lagoon is characterized by a high dinocyst abundance, reaching a maximum value of 2742 cysts.g(-1) of dry sediment. The investigated cyst diversity was characterized by the presence of 22 dominant dinocyst morphotypes belonging to 11 genera. Two dinoflagellate species dominated the assemblage: Alexandrium pseudogonyaulax and Protoperidinium claudicans, representing 29 to 89% and 5 to 38% of the total cyst abundance, respectively, depending on the station. Seven morphotypes belonging to potentially toxic species were detected, including Alexandrium minutum, A. pseudogonyaulax, Alexandrium catenella/tamarense species complex, Lingulodinium polyedrum, Gonyaulax cf. spinifera complex, Prorocentrum micans and Protoceratium reticulatum. Pearson correlation values showed a positive correlation (alpha = 0.05) between cyst abundance and both water content and fine silt sediment content. Clustering revealed that the highest abundance of cysts corresponds to stations presenting the higher amounts of heavy metals. The simultaneous autoregressive model (SAM) highlighted a significant correlation (alpha = 0.05) between cyst accumulation and two main factors: sediment water content and sediment content for several heavy metals, including Hg, Cd, Cu, Ni and Cr. These results suggest that the degree of heavy metal pollution could influence cyst accumulation patterns. (C) 2017 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 2153
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Auteur Brosset, P.; Le Bourg, B.; Costalago, D.; Banaru, D.; Van Beveren, E.; Bourdeix, J.-H.; Fromentin, J.-M.; Menard, F.; Saraux, C.
Titre Linking small pelagic dietary shifts with ecosystem changes in the Gulf of Lions Type Article scientifique
Année 2016 Publication (up) Revue Abrégée Mar. Ecol.-Prog. Ser.
Volume 554 Numéro Pages 157-171
Mots-Clés anchovy; anchovy engraulis-encrasicolus; climate; Dietary overlap; fish; food-web; NW Mediterranean; nw mediterranean sea; plankton; regime shifts; Sardine; size-fractionated zooplankton; southern benguela; Sprat; stable-isotope ratios; Trophic ecology
Résumé Since 2008, a severe decrease in size and body condition together with a demographic truncation has been observed in the sardine (secondarily in anchovy) population of the Gulf of Lions (NW Mediterranean Sea). In parallel, sprat biomass, which was negligible before, has increased tenfold. All of these changes have strongly affected the regional fisheries. Using trophic and isotopic data from contrasting periods of low versus high growth and condition, we investigated potential changes in diet and interspecific feeding interactions through time. Evidence of resource partitioning was found between sprat and both anchovy and sardine in 2004 and 2005. Since 2010, the isotopic niches of the 3 species have tended to overlap, suggesting higher risk of competition for food resources. Moreover, the wider trophic niche of sprat indicates higher variability in individual diets. Anchovy and sardine diet varied through time, with a high proportion of large copepods or cladocerans in periods of high growth and condition (1994 and 2007, respectively) versus a dominance of small copepods in the present (2011-2012). Furthermore, an important reduction in prey diversity was also identified in the diet of both anchovy and sardine during the most recent period. Our results support the hypothesis that changes in small pelagic fish growth, size and body condition and ultimately biomass could be due to bottom-up control characterized by changes in food availability and increasing potential trophic competition.
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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 0171-8630 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1642
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Auteur Heymans, J.J.; Coll, M.; Link, J.S.; Mackinson, S.; Steenbeek, J.; Walters, C.; Christensen, V.
Titre Best practice in Ecopath with Ecosim food-web models for ecosystem-based management Type Article scientifique
Année 2016 Publication (up) Revue Abrégée Ecol. Model.
Volume 331 Numéro Pages 173-184
Mots-Clés benguela ecosystem; dynamics; Ecological network analysis; Ecopath with Ecosim; Ecosystem-based management; Ecosystem modelling; exploited ecosystems; impacts; indicators; marine ecosystems; Monte Carlo; network analysis; nw mediterranean sea; shelf ecosystem; southern benguela; Time series fitting
Résumé Ecopath with Ecosim (EwE) models are easier to construct and use compared to most other ecosystem modelling techniques and are therefore more widely used by more scientists and managers. This, however, creates a problem with quality assurance; to address this we provide an overview of best practices for creating Ecopath, models. We describe the diagnostics that can be used to check for thermodynamic and ecological principles, and highlight principles that should be used for balancing a model. We then highlight the pitfalls when comparing Ecopath models using Ecological Network Analysis indices. For dynamic simulations in Ecosim we show the state of the art in calibrating the model by fitting it to time series using a formal fitting procedure and statistical goodness of fit. Finally, we show how Monte Carlo simulations can be used to address uncertainty in input parameters, and we discuss the use of models in a management context, specifically using the concept of 'key runs' for ecosystem-based management. This novel list of best practices for EwE models will enable ecosystem managers to evaluate the goodness of fit of the given EwE model to the ecosystem management question. (C) 2016 The Authors. Published by Elsevier B.V.
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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
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Numéro d'Appel MARBEC @ alain.herve @ collection 1644
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Auteur Panfili, J.; Darnaude, A.M.; Lin, Y.J.; Chevalley, M.; Iizuka, Y.; Tzeng, W.N.; Crivelli, A.J.
Titre Habitat residence during continental life of the European eel Anguilla anguilla investigated using linear discriminant analysis applied to otolith Sr:Ca ratios Type Article scientifique
Année 2012 Publication (up) Revue Abrégée Aquat. Biol.
Volume 15 Numéro 2 Pages 175-185
Mots-Clés Anguilla anguilla; Epma; European eel; La-Icpms; Mediterranean area; Otolith; Strontium:calcium ratio; coastal; elemental fingerprints; estuarine; fish otoliths; fresh-water environments; history; japonica; mass; microchemistry; rostrata; spectrometry; sr-ca ratios
Résumé European eel Anguilla anguilla migratory behaviour during continental life is still unclear due to the multiplicity of aquatic environments colonised by the species. In the Camargue area (NW Mediterranean), eel colonisation of the Fumemorte canal, a freshwater habitat that communicates only with a vast brackish ecosystem (the Vaccares lagoon), offers a rare opportunity to test for freshwater habitat residence during continental life. To this end, both laser ablation inductively coupled plasma mass spectrometry and electron probe micro-analysis were used to measure chronological variations of strontium concentrations (Sr:Ca) in the otoliths of 58 silver eels captured in the canal between 1997 and 2007. Comparing mean Sr: Ca ratios measured on otolith edges with the 2 analytical methods indicated that they provide comparable measurement accuracies. Linear discriminant analysis (LDA), based on the otolith Sr: Ca values corresponding to the initial entrance of the fish into the brackish ecosystem and their final capture in the freshwater canal, allowed successful discrimination of the 2 habitats and reconstruction of migratory history for all individuals. Six different migratory behaviours were identified. Eels that entered the freshwater canal did so either directly (67%) or after 1 to 2 yr spent in the lagoon (33%), with a subsequent majority of freshwater residents (55%) until their silvering. These results indicate the value of LDA for reconstructing habitat use during continental life using Sr: Ca ratios. They confirm the occurrence of freshwater residence during continental life in European eels, even in Mediterranean continental areas where brackish environments are predominant. This observed sedentary behaviour has implications for eel population management and conservation.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1864-7790 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 626
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Auteur Dalongeville, A.; Andrello, M.; Mouillot, D.; Lobreaux, S.; Fortin, M.-J.; Lasram, F.; Belmaker, J.; Rocklin, D.; Manel, S.
Titre Geographic isolation and larval dispersal shape seascape genetic patterns differently according to spatial scale Type Article scientifique
Année 2018 Publication (up) Revue Abrégée Evol. Appl.
Volume 11 Numéro 8 Pages 1437-1447
Mots-Clés caribbean reef fish; connectivity; divergent selection; ecological data; ecological genetics; landscape genetics; marine connectivity; marine fish; Mediterranean Sea; Mullus surmuletus; neighbor matrices; oceanography; population-structure; sea; seascape genetics; single nucleotide polymorphism; surmuletus
Résumé Genetic variation, as a basis of evolutionary change, allows species to adapt and persist in different climates and environments. Yet, a comprehensive assessment of the drivers of genetic variation at different spatial scales is still missing in marine ecosystems. Here, we investigated the influence of environment, geographic isolation, and larval dispersal on the variation in allele frequencies, using an extensive spatial sampling (47 locations) of the striped red mullet (Mullus surmuletus) in the Mediterranean Sea. Univariate multiple regressions were used to test the influence of environment (salinity and temperature), geographic isolation, and larval dispersal on single nucleotide polymorphism (SNP) allele frequencies. We used Moran's eigenvector maps (db-MEMs) and asymmetric eigenvector maps (AEMs) to decompose geographic and dispersal distances in predictors representing different spatial scales. We found that salinity and temperature had only a weak effect on the variation in allele frequencies. Our results revealed the predominance of geographic isolation to explain variation in allele frequencies at large spatial scale (>1,000km), while larval dispersal was the major predictor at smaller spatial scale (<1,000km). Our findings stress the importance of including spatial scales to understand the drivers of spatial genetic variation. We suggest that larval dispersal allows to maintain gene flows at small to intermediate scale, while at broad scale, genetic variation may be mostly shaped by adult mobility, demographic history, or multigenerational stepping-stone dispersal. These findings bring out important spatial scale considerations to account for in the design of a protected area network that would efficiently enhance protection and persistence capacity of marine species.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1752-4571 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2422
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