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Auteur Rossi, F.; Baeta, A.; Marques, J.C. doi  openurl
  Titre Stable isotopes reveal habitat-related diet shifts in facultative deposit-feeders Type Article scientifique
  Année 2015 Publication Revue Abrégée J. Sea Res.  
  Volume 95 Numéro Pages (down) 172-179  
  Mots-Clés Benthos; burying depth; carbon; Estuaries; estuarine habitats; food-web; Macrofauna; marine; polychaete nereis-diversicolor; scrobicularia-plana; Seagrass; seagrass meadows; Sediment; water-flow; zostera-noltii  
  Résumé Seagrass patches interspersed in a sediment matrix may vary environmental conditions and affect feeding habits of consumers and food-web structure. This paper investigates diet shifts between bare sediments and a Zostera noltei (Hornemann, 1832) meadow for three facultative deposit-feeding macrofaunal consumers, notably the bivalve Scrobicularia piano (da Costa, 1778), the polychaete Hediste diversicolor (O.T. Muller, 1776), and the gastropod Hydrobia ulvae (Pennant, 1778). In July 2008, one eelgrass meadow and two bare sediment locations were chosen in the Mondego estuary (40 degrees 08" N, 8 degrees 50'W, Portugal) and sampled for stable isotope signatures (delta C-13 and delta N-15) of macrofauna consumers and some of their potential basal food sources, such as sedimentary organic matter (SOM), microphytobenthos (MPB), seagrass shoots, leaves and seaweeds laying on the surface sediment. The delta N-15 of H. diversicolor was 3% higher in the eelgrass meadow than in bare sediment, indicating a change of trophic position, whereas the Bayesian stable-isotope mixing model showed that S. piano assimilated more macroalgal detritus than microphytobenthos in the eelgrass bed. Such habitat-related diet shifts have the potential to change structure and spatial dynamics of benthic food webs. (C) 2014 Elsevier B.V. All rights reserved.  
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  ISSN 1385-1101 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1549  
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Auteur RANJBAR, M.S.; ZOLGHARNIEN, H.; YAVARI, V.; ARCHANGI, B.; SALARI, M.A.; ARNAUD-HAOND, S.; CUNHA, R.L. url  doi
openurl 
  Titre Rising the Persian Gulf Black-Lip Pearl Oyster to the Species Level: Fragmented Habitat and Chaotic Genetic Patchiness in Pinctada persica Type Article scientifique
  Année 2016 Publication Revue Abrégée Evolutionary Biology  
  Volume 43 Numéro 1 Pages (down) 131-143  
  Mots-Clés Black-lip pearl oysters; Fragmented habitat; Persian Gulf; Pinctada persica; Species delimitation  
  Résumé Marine organisms with long pelagic larval stages are expected to exhibit low genetic differentiation due to their potential to disperse over large distances. Growing body of evidence, however, suggests that marine populations can differentiate over small spatial scales. Here we focused on black-lip pearl oysters from the Persian Gulf that are thought to belong to the Pinctada margaritifera complex given their morphological affinities. This species complex includes seven lineages that show a wide distribution ranging from the Persian Gulf (Pinctada margaritifera persica) and Indian Ocean (P. m. zanzibarensis) to the French Polynesia (P. m. cumingii) and Hawai'i (P. m. galtsoffi). Despite the long pelagic larval phase of P. m. persica, this lineage is absent from continental locations and can only be found on a few islands of the Persian Gulf. Mitochondrial COI-based analyses indicated that P. m. persica belongs to a clearly divergent ESU and groups with specimens from Mauritius (P. m. zanzibarensis). Microsatellite data, used here to assess the spatial scale of realized dispersal of Persian Gulf black-lip pearl oysters, revealed significant genetic structure among islands distant of only a few dozen kilometres. The scantiness of suitable habitats most likely restricted the distribution of this lineage originating the observed chaotic genetic patchiness. The hatchery-based enhancement performed in one of the sampled islands may also have affected population genetic structure. The long-term accumulation of genetic differences likely resulted from the allopatric divergence between P. m. persica and the neighbouring Indian Ocean black-lip pearl oysters.  
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  ISSN 0071-3260 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1519  
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Auteur Lopez, J.; Moreno, G.; Lennert-Cody, C.; Maunder, M.; Sancristobal, I.; Caballero, A.; Dagorn, L. doi  openurl
  Titre Environmental preferences of tuna and non-tuna species associated with drifting fish aggregating devices (DFADs) in the Atlantic Ocean, ascertained through fishers' echo-sounder buoys Type Article scientifique
  Année 2017 Publication Revue Abrégée Deep-Sea Res. Part II-Top. Stud. Oceanogr.  
  Volume 140 Numéro Pages (down) 127-138  
  Mots-Clés behavior; catch rates; Echo-sounder buoy; Environmental preferences; equatorial atlantic; fad; floating objects; french-polynesia; gamm; habitat; pacific-ocean; Pelagic fish; Purse seine; thunnus-albacares; Tropical tuna; Tuna; western indian-ocean  
  Résumé Understanding the relationship between environmental variables and pelagic species concentrations and dynamics is helpful to improve fishery management, especially in a changing environment. Drifting fish aggregating device (DFAD)-associated tuna and non-tuna biomass data from the fishers' echo-sounder buoys operating in the Atlantic Ocean have been modelled as functions of oceanographic (Sea Surface Temperature, Chlorophyll-a, Salinity, Sea Level Anomaly, Thermocline depth and gradient, Geostrophic current, Total Current, Depth) and DFAD variables (DFAD speed, bearing and soak time) using Generalized Additive Mixed Models (GAMMs). Biological interaction (presence of non-tuna species at DFADs) was also included in the tuna model, and found to be significant at this time scale. All variables were included in the analyses but only some of them were highly significant, and variable significance differed among fish groups. In general, most of the fish biomass distribution was explained by the ocean productivity and DFAD-variables. Indeed, this study revealed different environmental preferences for tunas and non-tuna species and suggested the existence of active habitat selection. This improved assessment of environmental and DFAD effects on tuna and non-tuna catchability in the purse seine tuna fishery will contribute to transfer of better scientific advice to regional tuna commissions for the management and conservation of exploited resources.  
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  ISSN 0967-0645 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2177  
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Auteur Eduardo Nole, L.; Frédou, T.; Souza Lira, A.; Padovani Ferreira, B.; Bertrand, A.; Ménard, F.; Lucena Frédou, F. url  doi
openurl 
  Titre Identifying key habitat and spatial patterns of fish biodiversity in the tropical Brazilian continental shelf Type Article scientifique
  Année 2018 Publication Revue Abrégée Continental Shelf Research  
  Volume 166 Numéro Pages (down) 108-118  
  Mots-Clés Demersal fish assemblage; Fish assemblage structure; Habitat composition; Marine Protected Areas; Northeast Brazilian coast; Underwater footages  
  Résumé Knowledge of the spatial distribution of fish assemblages biodiversity and structure is essential for prioritizing areas of conservation. Here we describe the biodiversity and community structure of demersal fish assemblages and their habitat along the northeast Brazilian coast by combining bottom trawl data and underwater footage. Species composition was estimated by number and weight, while patterns of dominance were obtained based on frequency of occurrence and relative abundance. A total of 7235 individuals (830 kg), distributed in 24 orders, 49 families and 120 species were collected. Community structure was investigated through clustering analysis and by a non-metric multidimensional scaling technique. Finally, diversity was assessed based on six indices. Four major assemblages were identified, mainly associated with habitat type and depth range. The higher values of richness were found in sand substrate with rocks, coralline formations and sponges (SWCR) habitats, while higher values of diversity were found in habitats located on shallow waters (10–30 m). Further, assemblages associated with sponge-reef formations presented the highest values of richness and diversity. In management strategies of conservation, we thus recommend giving special attention on SWCR habitats, mainly those located on depths between 30 and 60 m. This can be achieved by an offshore expansion of existing MPAs and/or by the creation of new MPAs encompassing those environments.  
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  ISSN 0278-4343 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2384  
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Auteur Rossi, F.; Colao, E.; Martinez, M.J.; Klein, J.C.; Carcaillet, F.; Callier, M.D.; De Wit, R.; Caro, A. url  doi
openurl 
  Titre Spatial distribution and nutritional requirements of the endosymbiont-bearing bivalve Loripes lacteus (sensu Poli, 1791) in a Mediterranean Nanozostera noltii (Hornemann) meadow Type Article scientifique
  Année 2013 Publication Revue Abrégée Journal of Experimental Marine Biology and Ecology  
  Volume 440 Numéro Pages (down) 108-115  
  Mots-Clés bacteria; Bivalve; codakia-orbicularis; food web; lucinoma-aequizonata; marine-invertebrates; mediterranean; new-zealand fjords; production; Seagrass; seagrass habitats; secondary; solemya-velum; Stable isotopes; sulfide-rich habitats; Symbiosis; thalassia-testudinum  
  Résumé Sulphur-oxidising endosymbiont-bearing bivalves often inhabit seagrass meadows, where they can control sulphide levels and variably contribute to carbon cycling, by feeding on endosymbiotic bacteria and/or on particulate organic matter from the water column. The patterns of variability in their feeding mode and their spatial distribution within the seagrass meadows are however poorly studied. Seagrass beds form naturally patchy habitats with seagrass-sand edges that may have variable effects on different organisms. The present study aims at understanding differences in feeding mode and abundance of the endosymbiont-bearing bivalve Loripes lacteus (sensu Poli, 1791) as well as the physiological conditions of its endosymbiotic populations between edge and inner portion of meadows of the eelgrass Nanozostera noltii (Hornemann). In July 2010, Loripes specimens were sampled in 4 eelgrass patches at 2 different locations in the Thau lagoon, South of France. There was a clear negative edge effect on the abundance of small individuals of Loripes, while large individuals were homogeneously distributed between edge and inner part of the meadow. Although Loripes isotopic signatures (delta C-13 and delta N-15) were always closer to those of its symbiotic bacteria than to those of suspension-feeding bivalves, eelgrass edge enhanced mixotrophic behaviour of small animals, which assimilated less bacterial carbon and nitrogen at the edge than in the inner part of the eelgrass meadow. No differences related to eelgrass edges were instead found for the bacterial populations harboured by Loripes. Rather, flow cytometry revealed large variability at small spatial scales. Although bacteria were always important for the nutrition of Loripes, these findings showed that seagrass edges may contribute to regulate feeding mode and population structure of Loripes, which may have implications for seagrass functioning. (C) 2012 Elsevier B.V. All rights reserved.  
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  ISSN 0022-0981 ISBN Médium  
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  Notes <p>ISI Document Delivery No.: 105SJ<br/>Times Cited: 0<br/>Cited Reference Count: 57<br/>Rossi, Francesca Colao, Elodie Jose Martinez, Maria Klein, Judith C. Carcaillet, Frederique Callier, Myriam D. de Wit, Rutger Caro, Audrey<br/>Ec2co<br/>The authors wish to thank Patrice Got for its support in cytometric analyses. This work was partly supported by the EC2CO funded project “Le Cycle du carbone dans les reseaux trophiques des Herbiers face a l' Augmentation de la tempeRature et des sels nutritifs dans les lagunes Mediterraneennes (CHARM)” attributed to FR. [ST]<br/>Elsevier science bv<br/>Amsterdam</p> Approuvé pas de  
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