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Auteur Meddeb, M.; Niquil, N.; Grami, B.; Mejri, K.; Haraldsson, M.; Chaalali, A.; Pringault, O.; Hlaili, A.S.
Titre A new type of plankton food web functioning in coastal waters revealed by coupling Monte Carlo Markov chain linear inverse method and ecological network analysis Type Article scientifique
Année 2019 Publication Revue Abrégée Ecol. Indic.
Volume 104 Numéro Pages (down) 67-85
Mots-Clés Bacterial multivorous food web; biogenic carbon; Coastal waters; continental-shelf; Ecology; ecosystem attributes; flow networks; Food web modeling; grazing impact; gulf; mediterranean sea; model analysis; Network analysis; Seasonal variations; seasonal-dynamics; trophic network; Trophic structure
Résumé Plankton food webs (PFW) typology is based on different categories of functioning, according to the dominant processes and the role played by heterotrophic bacteria, small vs large phytoplankton, and small vs large zooplankton. Investigating the structure and the function of planktonic food webs in two SW Mediterranean waters (inshore and marine sites) at four seasons, using inverse (LIM-MCMC) and ecological network (ENA) analyses, we identified a new type of food web, called the “bacterial multivorous food web”. This food web adds to the conventional trophic continuum as previously reported. The “bacterial multivorous food web” present in winter showed the lowest primary production among seasons, but highest bacterial production. Several food web ratios characterized this new typology e.g. picophytoplankton net primary production to total primary production varied from 0.20 to 0.28; bacterial to primary production ratio is higher than values reported in global scale (congruent to 1); bacterial net production to the potential protozoan prey net production was high (>0.2). In this special food web, carbon was mostly recycled, with a moderate fraction channeled to deep waters, which lead to a higher retention of carbon inside the ecosystem. This winter PFW also seemed to be the most organized, specialized, stable and mature, as related to common interpretations of ENA. The spring was characterized by herbivorous food web, with highest activity coinciding with low stability. Although less usual, the herbivorous pathway was also observed during summer, in inshore waters. The autumn food webs, which functioned as multivorous or microbial food webs, appeared to be stable and mature. Finally, our study demonstrates the usefulness of food web models derived ratios combined with ecological network analysis indices to conduct evaluation of the structure and functioning of ecosystems and potentially to support management decisions in marine environment.
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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 1470-160x ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2596
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Auteur Guilhaumon, F.; Basset, A.; Barbone, E.; Mouillot, D.
Titre Species–area relationships as a tool for the conservation of benthic invertebrates in Italian coastal lagoons Type Article scientifique
Année 2012 Publication Revue Abrégée Estuarine Coastal and Shelf Science
Volume 114 Numéro Pages (down) 50-58
Mots-Clés Water Framework Directive; conservation biology; model selection; non-parametric richness estimators; transitional waters; zoobenthos
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Langue Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0272-7714 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 871
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Auteur Boukef, I.; Bejaoui, B.; Hassan, M.B.; Mraouna, R.; Got, P.; Harzallah, A.; Elbour, M.
Titre Spatial distribution and decay rates of coliforms in the sediments and water column of the bizerte lagoon Type Article scientifique
Année 2012 Publication Revue Abrégée Vie Milieu
Volume 62 Numéro 1 Pages (down) 29-36
Mots-Clés bizerte lagoon; coastal waters; contamination; environmental-conditions; escherichia coli decay; estuarine; fecal indicator bacteria; pathogenic bacteria; pollution; recreational waters; seasonal survey; seawater; sunlight; sunlight inactivation; total coliform
Résumé In order to assess the impact of bacterial input loads in Bizerte lagoon (Northern Tunisia), a seasonal survey was done for total coliform bacteria covering the whole lagoon area, to reproduce and prevent dispersion of input loads of terrestrial discharges in the lagoon. Effect of solar radiation on Escherichia coli strains was investigated using seawater microcosms comparatively exposed to sunlight and dark conditions. The results revealed (i) high charges of coliforms in the sediment rather than in the water column, (ii) total coliforms increased periodically with season in both compartments, (iii) anthropogenic discharges influence coastal areas of the lagoon, and (iv) solar radiation has an effect on decay rate of E. coli maintained in microcosm experiments.
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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 0240-8759 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 846
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Auteur Blanchet, M.; Pringault, O.; Panagiotopoulos, C.; Lefevre, D.; Charriere, B.; Ghiglione, J.-F.; Fernandez, C.; Aparicio, F.L.; Marrase, C.; Catala, P.; Oriol, L.; Caparros, J.; Joux, F.
Titre When riverine dissolved organic matter (DOM) meets labile DOM in coastal waters: changes in bacterial community activity and composition Type Article scientifique
Année 2017 Publication Revue Abrégée Aquat. Sci.
Volume 79 Numéro 1 Pages (down) 27-43
Mots-Clés Bacterial community composition; bacterioplankton; biodegradation; carbon; coastal waters; Dissolved organic matter; Fluorescence; growth efficiency; lake water; marine; Mediterranean Sea; open-ocean; Priming effect; rhone river; terrestrial
Résumé Heterotrophic bacterial communities in marine environments are exposed to a heterogeneous mixture of dissolved organic compounds with different bioreactivity that may control both their activity and composition. The coastal environment is an example of a mixing area where recalcitrant allochthonous organic matter from rivers can encounter labile organic matter from marine phytoplanktonic blooms. The objective of this study was to explore the effects of mixed qualities of dissolved organic matter (DOM) on bacterial community activity (BCA) and bacterial community composition (BCC) and to test for a priming effect when DOM sources are added in combination. Coastal marine bacterial communities were incubated separately with a mixture of amino acids and with natural riverine DOM or with both sources together for 42 days. Addition of amino acids alone or in combination with riverine DOM led to a similar stimulation of BCA compared to control condition, whereas addition of riverine DOM alone did not modify BCA compared to the control. On the contrary, BCC analyzed by 16S rRNA gene pyrosequencing was not affected by the addition of amino acids alone, but changed dramatically with riverine DOM alone or in combination with amino acids. Our results show that changes in BCA and BCC can be driven by different types of DOM, but that these changes are not necessarily coupled. Moreover, the addition of labile DOM did not modify the microbial decomposition of riverine DOM, nor the BCC, suggesting that a priming effect did not occur under these experimental conditions.
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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 1015-1621 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2090
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Auteur Alves-Junior, F. de A.; Bertrand, A.; Camara de Araujo, M. de A.L.; de Carvalho Paiva, R.J.; de Souza-Filho, J.F.
Titre First Report of the Ectoparasitic Isopod, Holophryxus acanthephyrae Stephensen 1912 (Cymothoida: Dajidae) in the South Atlantic: Recovered from a New Host, the Deep-Sea Shrimp, Acanthephyra acanthitelsonis Spence Bate, 1888 Type Article scientifique
Année 2019 Publication Revue Abrégée Thalassas
Volume 35 Numéro 1 Pages (down) 13-15
Mots-Clés Brazilian waters; Deep-sea shrimp; epicaridea; genus; Isopods; Parasitism; Rocas Atoll
Résumé The crustacean family of isopods, Dajidae, comprises 18 genera containing 54 species with widespread distribution. The species of this family are ectoparasites, especially on euphausiids, mysids and shrimps. The species of Holophryxus acanthephyrae has a life cycle involving a first intermediate host (copepod) and a definitive host (shrimp), and adheres particularly on deep-sea shrimps of genus Acanthephyra. Here, we make the first report of dajid isopod Holophryxus acanthephyrae from Brazilian waters (South Atlantic) and the first occurrence as parasite on deep-sea shrimp Acanthephyra acanthitelsonis. The specimen was collected under the framework of the project ABRACOS 2 (Acoustic along the BRazilian COast), on board of R/V Antea in April 2017, using a Micronekton net (mesh size of 10mm) in Rocas Atoll. The specimen female of Holophryxus acanthephyrae was found in pelagic zone in Rocas Atoll, at 630m depth. This study increases the knowledge on Dajidae family and their host range.
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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 0212-5919 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2581
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