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Registros recuperados: 36
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Are food web structures well represented in isotopic spaces? ArchiMer
Jabot, Franck; Giraldo, Carolina; Lefebvre, Sebastien; Dubois, Stanislas.
Isotopic analyses are increasingly used to assess the structure of food webs and a series of isotopic functional indices have been proposed in the last decade to characterize this structure. These indices are based on the foundational assumption that proximity in the isotopic space informs on trophic similarity between species. While it has been recognized for long that this simplifying assumption should be used with caution, no formal evaluation of its domain of validity has been performed to date. We here simulate a large number (15,000) of food webs with varying characteristics to assess i) whether isotopic distance is a good proxy of trophic dissimilarity; ii) whether isotopic functional indices are good proxies of trophic functional properties; and...
Tipo: Text Palavras-chave: Connectance; Isotopic functional indices; Niche model; Omnivory; Virtual ecology.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00385/49596/50110.pdf
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Climate hindcasts: exploring the disjunct distribution of Diopatra biscayensis ArchiMer
Wethey, David S.; Woodin, Sarah A.; Berke, Sarah K.; Dubois, Stanislas.
The ecosystem engineer onuphid polychaete Diopatra biscayensis has a continuous population in the Bay of Biscay from the Cantabria coast in Spain to southern Brittany in France. A group of disjunct populations also are found in the English Channel, separated from the Biscay population by more than 400 coastal kilometers. It remains unclear whether D. biscayensis is native to the Bay of Biscay; it is also debated whether the disjunct populations in the English Channel are relics of a formerly continuous population, or the product of recent introductions through aquaculture. Here, we use climate hindcasts to explore hypotheses about the D. biscayensis historical distribution in Europe. If D. biscayensis is native, its range would have been restricted to...
Tipo: Text Palavras-chave: Climate change; Biogeography; Metapopulation; Diopatra; Historical projections.
Ano: 2016 URL: http://archimer.ifremer.fr/doc/00356/46711/46974.pdf
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Connecting organic to mineral: How the physiological state of an ecosystem-engineer is linked to its habitat structure ArchiMer
Curd, Amelia; Pernet, Fabrice; Corporeau, Charlotte; Delisle, Lizenn; Firth, Louise B.; Nunes, Flavia; Dubois, Stanislas.
The honeycomb worm Sabellaria alveolata is capable of building extensive bioconstructions, including what are currently considered Europe’s largest biogenic reefs. The size and volume of these bioconstructions, however, vary greatly, such that not all habitats engineered by S. alveolata may be easily identified as reefs. Given that European environmental legislation protects marine habitats that are classified as “reefs”, it is important to identity a clear set of definition criteria. Furthermore, quantifiable and unequivocal criteria are also needed to evaluate the ecological (health) state of these reefs, in order to best monitor and protect them. Here we propose new terminology to describe the physical appearance of these bioconstructions and attempt to...
Tipo: Text Palavras-chave: Biochemical indicators; Health; Ecological status; Sabellaria alveolata; Biogcnic reef; Engineer species.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00464/57608/60175.pdf
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Diversity and composition of macrobenthic community associated with sandy shoals of the Louisiana continental shelf ArchiMer
Dubois, Stanislas; Gelpi, Carey; Condrey, Richard E.; Grippo, Mark A.; Fleeger, John W..
Along the Louisiana, USA continental shelf, sandy shoals are shallow, possibly oxygen-rich "islands" surrounded by deeper muddy deposits prone to hypoxia. Shoals also contain significant quantities of fine sand that may be mined in the future for coastal restoration. The ecological role of shoals remains poorly understood and we hypothesized that shoals provide critical habitat for benthic invertebrates. Using Ship Shoal as a model system, we assessed the diversity and structure of macrobenthic assemblages and how community structure varies with season and environmental parameters. High biomass (averaging 26.7 g m(-2)) and high diversity (161 species) of macrobenthos was found in 2006. Polychaetes (45%-72 species) and crustaceans comprised most of the...
Tipo: Text Palavras-chave: Shallow habitat; Sand bank; Louisiana; Hypoxia refuge; Gulf of Mexico; Continental shelf; Biodiversity hotspot.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6975.pdf
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Ephemeral Bio-engineers or Reef-building Polychaetes: How Stable are Aggregations of the Tube Worm Lanice conchilega (Pallas, 1766)? ArchiMer
Callaway, Ruth; Desroy, Nicolas; Dubois, Stanislas; Fournier, Jerome; Frost, Matthew; Godet, Laurent; Hendrick, Vicki J.; Rabaut, Marijn.
Dense aggregations of tube-worms can stabilize sediments and generate oases for benthic communities that are different and often more diverse and abundant than those of the surroundings. If these features are to qualify as biogenic reefs under nature-conservation legislation such as the EC Habitats Directive, a level of stability and longevity is desirable aside from physical and biological attributes. Lanice conchilega (Pallas, 1766) is widely distributed around the European coast and aggregations of this tube-dwelling polychaete are known to have a positive effect on the biodiversity of associated species in inter- and sub-tidal areas. This increases the value of L. conchilega-rich habitats for higher trophic levels such as birds and fish. However, L....
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Ano: 2010 URL: http://archimer.ifremer.fr/doc/00011/12222/9284.pdf
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Etude d’un champ de pockmarks associé à un peuplement de Haploops dans la Baie de Concarneau : apport de la prospection géophysique THR ArchiMer
Baltzer, Agnes; Ehrhold, Axel; Rigolet, Carinne; Dubois, Stanislas; Cordier, Celine.
Tipo: Text
Ano: 2013 URL: http://archimer.ifremer.fr/doc/00281/39232/37792.pdf
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Evaluation de la sensibilité des habitats élémentaires (DHFF) d’Atlantique, de Manche et de Mer du Nord aux pressions physiques ArchiMer
La Riviere, Marie; Aish, Annabelle; Auby, Isabelle; Ar Gall, Erwan; Dauvin, Jean-claude; De Bettignies, Thibaut; Derrien-courtel, Sandrine; Dubois, Stanislas; Gauthier, Olivier; Grall, Jacques; Janson, Anne Laure; Thiebaut, Eric.
Le Ministère de l’Environnement de l’Energie et de la Mer a confié au Service du Patrimoine Naturel (Muséum National d’Histoire Naturelle), en lien étroit avec les acteurs de la recherche scientifique, la coordination d’un projet sur l’évaluation de la sensibilité des habitats benthiques aux pressions d’origine anthropique. L’objectif de ce travail est de qualifier la sensibilité générique des habitats présents en France métropolitaine pour aider à l’orientation et à la priorisation de mesures de gestion (pour des activités actuelles ou futures), adaptées aux enjeux de conservation, afin de respecter les objectifs d’atteinte ou de maintien d’un ECF (DCSMM) ou BEE (DHFF). Ce travail permet également de mettre en évidence les habitats et/ou les pressions...
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Ano: 2017 URL: http://archimer.ifremer.fr/doc/00376/48699/49033.pdf
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Évolution du récif à Sabellaria alveolata (L.) de la baie du Mont-Saint-Michel ArchiMer
Ricquiers, Laurent; Desroy, Nicolas; Dubois, Stanislas; Guerin, Laurent; Gerla, Daniel; Legendre, Aurelie; Le Mao, Patrick; Rougerie, Michel.
L’état de santé du récif à Sabellaria alveolata de Sainte-Anne a été évalué afin de juger des conséquences des activités menées en baie du Mont Saint Michel (conchyliculture, pêche à pied…) sur ce patrimoine naturel remarquable. Un relevé de différents paramètres a été conduit en 2002 (Dubois, 2003), puis en 2007 sur ce récif subdivisé en carrés de 75x75m. Parmi les données collectées, ont été cartographiées (à l’aide du logiciel SURFER®) afin d’apprécier l’évolution du récif : (1) le recouvrement du récif par les huîtres ; (2) le degré de fragmentation et (3) l’indice d’état de santé (IS)
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Ano: 2007 URL: https://archimer.ifremer.fr/doc/00156/26686/24748.pdf
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Feeding response of the polychaete Sabellaria alveolata (Sabellariidae) to changes in seston concentration ArchiMer
Dubois, Stanislas; Barille, Laurent; Cognie, Bruno.
Sabellaria alveolata is a tube-building gregarious polychaete that constructs large biogenic reefs. In macrotidal shellfish ecosystems, this species competes for food with cultivated suspension-feeders. The suspension-feeding activity and clearance rate of S. alveolata were investigated in response to changes in seston concentration. A flow-through system was designed to study 225 cm(2) reef blocks with more than 500 individuals. The experimental conditions were characterized by increasing concentrations of suspended particulate matter ranging from 6.5 to 153.8 mg L-1, while the organic content of the diet (microalgae Skeletonema costatum) decreased inversely from 49 to 9%, to mimic the dilution of organic matter by inorganic particles, characteristic of...
Tipo: Text Palavras-chave: Bay of Mont Saint Michel; Tubiculous polychaete; Trophic capacity; Suspension feeders; Reefs; Feeding activity.
Ano: 2009 URL: http://archimer.ifremer.fr/doc/2009/publication-6778.pdf
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Food web structures of subtidal benthic muddy habitats: evidence of microphytobenthos contribution supported by an engineer species ArchiMer
Rigolet, Carinne; Thiebaut, Eric; Dubois, Stanislas.
Stable carbon and nitrogen isotopic composition (delta C-13 and delta N-15) of benthic organisms was investigated to understand the effects of a gregarious tubicolous amphipod species (Haploops nirae) on benthic food web structures and test whether drastic changes in species composition cause changes in food web structure. The habitat engineered by this species was sampled and compared with the adjacent uncolonized Amphiura filiformis muddy habitat in winter and summer. The isotopic signatures of macrofaunal and megafaunal species associated with both habitats were analysed along with potential food sources at each sampling period. Similar food web structures for each habitat (and each season), with high delta N-15 ranges spanning over 3 trophic levels,...
Tipo: Text Palavras-chave: Stable isotopes; Gregarious amphipod; Source contribution; Haploops; Benthic diatoms; Navicula.
Ano: 2014 URL: https://archimer.ifremer.fr/doc/00187/29822/28259.pdf
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Food-Web Complexity in Guaymas Basin Hydrothermal Vents and Cold Seeps ArchiMer
Portail, Marie; Olu, Karine; Dubois, Stanislas; Escobar-briones, Elva; Gelinas, Yves; Menot, Lenaick; Sarrazin, Jozee.
In the Guaymas Basin, the presence of cold seeps and hydrothermal vents in close proximity, similar sedimentary settings and comparable depths offers a unique opportunity to assess and compare the functioning of these deep-sea chemosynthetic ecosystems. The food webs of five seep and four vent assemblages were studied using stable carbon and nitrogen isotope analyses. Although the two ecosystems shared similar potential basal sources, their food webs differed: seeps relied predominantly on methanotrophy and thiotrophy via the Calvin-Benson-Bassham (CBB) cycle and vents on petroleum-derived organic matter and thiotrophy via the CBB and reductive tricarboxylic acid (rTCA) cycles. In contrast to symbiotic species, the heterotrophic fauna exhibited high...
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Ano: 2016 URL: http://archimer.ifremer.fr/doc/00353/46390/46018.pdf
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Forces, failles et opportunités de la recherche française en écologie trophique ArchiMer
Perga, Marie-elodie; Danger, Michael; Dubois, Stanislas; Fritch, Clementine; Gaucherel, Cedric; Hubas, Cedric; Jabot, Franck; Lacroix, Gerard; Lefebvre, Sebastien; Marmonier, Pierre; Bec, Alexandre.
The French National Institute of Ecology and Environment (INEE) aims at fostering pluridisciplinarity in Environmental Science and, for that purpose, funds ex muros research groups (GDR) on thematic topics. Trophic ecology has been identified as a scientific field in ecology that would greatly benefit from such networking activity, as being profoundly scattered. This has motivated the seeding of a GDR, entitled “GRET”. The contours of the GRET's action, and its ability to fill these gaps within trophic ecology at the French national scale, will depend on the causes of this relative scattering. This study relied on a nationally broadcasted poll aiming at characterizing the field of trophic ecology in France. Amongst all the unique individuals that fulfilled...
Tipo: Text Palavras-chave: Trans-ecosystem; Scientific network; Cleavage; Ecology; Population; Community.
Ano: 2018 URL: http://archimer.ifremer.fr/doc/00442/55338/56849.pdf
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Functional roles of an engineer species for coastal benthic invertebrates and demersal fish ArchiMer
Chaalali, Aurelie; Brind'Amour, Anik; Dubois, Stanislas; Le Bris, Herve.
Through their tissues or activities, engineer species create, modify, or maintain habitats and alter the distribution and abundance of many plants and animals. This study investigates key ecological functions performed by an engineer species that colonizes coastal ecosystems. The gregarious tubiculous amphipod Haploops nirae is used as a biological model. According to previous studies, the habitat engineered by H.nirae (i.e., Haploops habitat) could provide food and natural shelter for several benthic species such as benthic diatoms belonging to the gender Navicula, the micrograzer Geitodoris planata, or the bivalve Polititapes virgineus. Using data from scientific surveys conducted in two bays, this study explored whether (1) the Haploops sandy-mud...
Tipo: Text Palavras-chave: Coastal nurseries; Fish community; Haploops nirae; Isotopic diversity indices; Stable isotopes.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00396/50722/51431.pdf
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Group sweeping: Feeding activity and filtration rate in the tubiculous amphipod Haploops nirae (Kaim-Malka, 1976) ArchiMer
Rigolet, Carinne; Le Souchu, Pierrick; Caisey, Xavier; Dubois, Stanislas.
Haploops nirae is a gregarious tubiculous amphipod that uses its two pairs of antennae to filter particles from the water column. Recent sonar mappings of Haploops seabeds revealed that thousands of hectares of softbottom muddy sediments in South Brittany coastal ecosystems are now colonized by this amphipod. The present study investigates (1) the structure of the feeding organs and the mechanisms involved in particle capture, (2) the effect of environmental parameters (current velocity, turbidity and food concentration) on the feeding activity of H. nirae, quantified by the percentage of active individuals, the frequency of antennae beats and the number and duration of feeding events and (3) the retention efficiency and clearance rate of H. nirae...
Tipo: Text Palavras-chave: Amphipods; Ampeliscidae; Clearance rate; Gregarious suspension-feeders; Grazing impact; Retention efficiency; South-Brittany.
Ano: 2011 URL: http://archimer.ifremer.fr/doc/00043/15418/18268.pdf
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Improving Intertidal Reef Mapping Using UAV Surface, Red Edge, and Near-Infrared Data ArchiMer
Collin, Antoine; Dubois, Stanislas; James, Dorothée; Houet, Thomas.
Coastal living reefs provide considerable services from tropical to temperate systems. Threatened by global ocean-climate and local anthropogenic changes, reefs require spatially explicit management at the submeter scale, where socioecological processes occur. Drone surveys have adequately addressed these requirements with red-green-blue (RGB) orthomosaics and digital surface models (DSMs). The use of ancillary spectral bands has the potential to increase the mapping of all reefscapes that emerge during low tide. This research investigates the contribution of the drone-based red edge (RE), near-infrared (NIR), and DSM into the classification accuracy of five main habitats of the largest intertidal biogenic reefs in Europe, built by the honeycomb worm...
Tipo: Text Palavras-chave: Reefs; Red edge; Near-infrared; Digital surface model; Classification; Sabellaria alveolata.
Ano: 2019 URL: https://archimer.ifremer.fr/doc/00512/62326/66584.pdf
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Influences of geothermal sulfur bacteria on a tropical coastal food web ArchiMer
Pascal, Pierre-yves; Dubois, Stanislas; Goffette, Anais; Lepoint, Gilles.
The activity of the geothermal plant at Bouillante in Guadeloupe (French West Indies) releases thioautotrophic bacteria into the coastal environment. Fish counts reveal that fish abundance increases with higher availability of this bacterial resource. In order to evaluate the trophic role of these bacteria, isotopic compositions (C, N, S) of potential consumers were evaluated on transects at increasing distance from the source of bacteria. The 3 mobile fish species examined (Abudefduf saxatilis, Acanthurus bahianus, and Stegastes partitus) ingested and assimilated chemosynthetic bacteria. Similarly, the isotopic composition of the mobile sea urchin Diadema antillarum was different close to the discharge channel, suggesting a diet mainly composed of sulfur...
Tipo: Text Palavras-chave: Shallow vent; Food web; Sulfur bacteria; Stable isotope.
Ano: 2017 URL: http://archimer.ifremer.fr/doc/00404/51511/52256.pdf
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Interplay between abiotic factors and species assemblages mediated by the ecosystem engineer Sabellaria alveolata (Annelida: Polychaeta) ArchiMer
Jones, Auriane; Dubois, Stanislas; Desroy, Nicolas; Fournier, Jerome.
abellaria alveolata is a gregarious polychaete that uses sand particles to build three-dimensional structures known as reefs, fixed atop rocks or built on soft sediments. These structures are known to modify the local grain-size distribution and to host a highly diversified macrofauna, altered when the reef undergoes disturbances. The goal of this study was to investigate the different sedimentary and biological changes associated with the presence of a S. alveolata reef over two contrasting seasons (late winter and late summer), and how these changes were linked. Three different sediments were considered: the engineered sediment (the actual reef), the associated sediment (the soft sediment surrounding the reef structures) and a control soft sediment (i.e....
Tipo: Text Palavras-chave: Honeycomb worm; Macrobenthos; Benthic primary production; Habitat disturbance; Silt; Beta diversity; France; Brittany; Mont Saint-Michel Bay.
Ano: 2018 URL: http://archimer.ifremer.fr/doc/00405/51649/52198.pdf
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Isotopic Diversity Indices: How Sensitive to Food Web Structure? ArchiMer
Brind'Amour, Anik; Dubois, Stanislas.
Recently revisited, the concept of niche ecology has lead to the formalisation of functional and trophic niches using stable isotope ratios. Isotopic diversity indices (IDI) derived from a set of measures assessing the dispersion/distribution of points in the δ-space were recently suggested and increasingly used in the literature. However, three main critics emerge from the use of these IDI: 1) they fail to account for the isotopic sources overlap, 2) some indices are highly sensitive to the number of species and/or the presence of rare species, and 3) the lack of standardization prevents any spatial and temporal comparisons. Using simulations we investigated the ability of six commonly used IDI to discriminate among different trophic food web structures,...
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Ano: 2013 URL: http://archimer.ifremer.fr/doc/00171/28270/26522.pdf
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Les fonds marins de Bretagne, un patrimoine remarquable : connaître pour mieux agir ArchiMer
Bajjouk, Touria; Duchene, Julie; Guillaumont, Brigitte; Maud, Bernard; Blanchard, Michel; Derrien-courtel, Sandrine; Dubois, Stanislas; Grall, Jacques; Hamon, Dominique; Hily, Christian; Le Gal, Aodren; Rigolet, Carine; Rossi, Nadège; Ledard, Michel.
Depuis la fin des années 90, les besoins de connaissance et de suivi de la biodiversité marine se sont accrus sensiblement. Les attentes sont motivées par la nécessité de mieux évaluer aussi bien l’impact du changement climatique que celui des activités anthropiques. Fortement convoitées, la faune et la flore benthiques sont en effet soumises à de multiples perturbations générées par les activités humaines, soit physiquement (effets de la pêche aux engins traînants, extractions de granulats, conchyliculture, etc.), soit résultant de pollutions chroniques (rejets urbains, industriels et agricoles) ou d’apports accidentels (pollutions pétrolières, introduction d'espèces exogènes). Il s’agit également de contribuer aux mesures de gestion ou de protection des...
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Ano: 2015 URL: http://archimer.ifremer.fr/doc/00311/42243/41811.pdf
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Lipid remodelling in the reef-building honeycomb worm, Sabellaria alveolata, reflects acclimation and local adaptation to temperature ArchiMer
Muir, Anna; Nunes, Flavia; Dubois, Stanislas; Pernet, Fabrice.
Acclimation and adaptation, which are key to species survival in a changing climate, can be observed in terms of membrane lipid composition. Remodelling membrane lipids, via homeoviscous adaptation (HVA), counteracts membrane dysfunction due to temperature in poikilotherms. In order to assess the potential for acclimation and adaptation in the honeycomb worm, Sabellaria alveolata, a reef-building polychaete that supports high biodiversity, we carried out common-garden experiments using individuals from along its latitudinal range. Individuals were exposed to a stepwise temperature increase from 15 °C to 25 °C and membrane lipid composition assessed. Our results suggest that S. alveolata was able to acclimate to higher temperatures, as observed by a...
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Ano: 2016 URL: https://archimer.ifremer.fr/doc/00354/46551/46361.pdf
Registros recuperados: 36
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