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Auteur (up) 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 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
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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 (up) 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 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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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 (up) Bodin, N.; Lesperance, D.; Albert, R.; Hollanda, S.; Michaud, P.; Degroote, M.; Churlaud, C.; Bustamante, P.
Titre Trace elements in oceanic pelagic communities in the western Indian Ocean Type Article scientifique
Année 2017 Publication Revue Abrégée Chemosphere
Volume 174 Numéro Pages 354-362
Mots-Clés atlantic-ocean; blue marlin; Environmental risk assessment; makaira-nigricans; Marine fish; Mediterranean Sea; Mercury; mercury content; North Pacific; risk-assessment; Seafood; Selenium; swordfish xiphias-gladius; Tuna fisheries' bycatch
Résumé The mineral composition of target and non-target pelagic fish caught by purse-seiners and longliners in the western-central Indian Ocean was determined. From the 10 essential elements analysed, selenium and zinc showed the highest concentrations in swordfish and blue marlin while Indian mackerel appeared as a good source of copper, iron and chrome. All catch had levels of lead and cadmium, two toxic elements, below the maximum sanitary limits. Although some concerns were raised regarding mercury concentrations in the largest species (wahoo, swordfish and blue marlin), molar ratios of mercury and selenium indicate that all oceanic pelagic fish from the western-central Indian Ocean are safe for human consumption. This study also gives insights on the relationships between the levels of essential and toxic elements in fish muscle and the size, trophic position and diet sources of the studied pelagic species. (C) 2017 Elsevier Ltd. All rights reserved.
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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 0045-6535 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2119
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Auteur (up) Bonnet, D.; Molinero, J.C.; Schohn, T.; Yahia, M.N.D.
Titre Seasonal changes in the population dynamics of Aurelia aurita in Thau lagoon Type Article scientifique
Année 2012 Publication Revue Abrégée Cah. Biol. Mar.
Volume 53 Numéro 3 Pages 343-347
Mots-Clés Aurelia aurita; Mediterranean Sea; abundance; fishes; jellyfish; lagoon; scyphomedusae; sea
Résumé Seasonal dynamics of the scyphomedusae, Aurelia aurita, was investigated twice a month from January 2010 to June 2011 and related to environmental conditions in Thau lagoon, southwestern Mediterranean Sea. Strobilation, indicated by the presence of 1 mm ephyrae, occurred from November to the middle of April. Maximum abundances up to 330 ind.100 m(-3) were reached in May 2011, few weeks after the last ephyrae release. The population declines afterwards steadily until disappearing from the water column. Concurrent with increased water temperature and mesozooplankton predation during May, growth rates increased from 0.04 mm.day(-1) to a peak of 4.5 mm.day(-1), with a maximum bell diameter of 11.3 cm reached on the 7th May. During the study period, there was no advection of A. aurita between Thau lagoon and the coastal waters.
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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 0007-9723 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 820
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Auteur (up) Bouchoucha, M.; Pecheyran, C.; Gonzalez, J.L.; Lenfant, P.; Darnaude, A.M.
Titre Otolith fingerprints as natural tags to identify juvenile fish life in ports Type Article scientifique
Année 2018 Publication Revue Abrégée Estuar. Coast. Shelf Sci.
Volume 212 Numéro Pages 210-218
Mots-Clés coastal habitats; Coastal areas; Contamination; elemental fingerprints; Fish; genus diplodus; la-icpms; nursery habitats; Nursery habitats; situ speciation measurements; sparid fishes; stable-isotopes; thin-films dgt; water chemistry; western mediterranean sea
Résumé The construction of ports has caused substantial habitat destruction in coastal areas previously used as nursery grounds by many fish species, with consequences to fish stocks. These artificial coastal areas might provide alternative nursery habitats for several species for juvenile fish abundances and growth in ports, although their contribution to adult stocks had never been estimated. The variability of otolith composition in the juveniles of two Diplodus species was investigated in three contrasting port areas and two adjacent coastal juvenile habitats of the Bay of Toulon (northwestern Mediterranean) in order to determine the possible use of otolith fingerprints as natural tags for the identification of juvenile fishes in ports. The global accuracy of discrimination between ports and coastal areas was very high (94%) irrespective of species, suggesting that otolith fingerprints can be used with confidence to retrospectively identify past residency in the ports of this bay. However, Ba was systematically the most discriminating element, since its concentrations in otoliths were generally higher outside ports than in inside them, probably due to river runoff. Moreover, otolith signatures varied greatly by species and between sampling sites. Furthermore, although Cu and Pb concentrations in water were at least 2.3-34-fold higher inside ports than outside, this was not consistently reflected in fish otoliths, confirming that spatial differences in otolith concentrations depend on the species and do not directly reflect differences in environmental contamination levels. Therefore, it seems unlikely that otolith microchemistry could provide a universal fingerprint capable of discriminating ports from other coastal areas. Nevertheless, the contribution of ports to adult fish populations can be determined well by establishing a library of otolith fingerprints for all juvenile habitats.
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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 0272-7714 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2427
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