Éditeur(s) : HAL CCSD
Résumé : Coral reefs are amongst the richest and more emblematic ecosystems of the world. These hotspots of biodiversity provide many services to Human societies, bringing leisure and economic added values. In many areas, especially developing countries, these ecosystems are submitted to both climate change (rise of sea temperature and level, acidification) and human coastal pressures (urbanisation, resources exploitation). In this context, an increasing number of Marine Protected Areas is settled on coral reefs environments in order to ensure their conservation and to mitigate local pressures. Hence, one of MPAs Managers' missions is to bring ecological and social data together to build integrated indicators of effectiveness. In Reunion Island, a MPA called the Marine reserve of La Réunion was settled in 2007 along a densely urbanised and populated fringing reef coast. In order to better evaluate its MPA effectiveness, the manager requires the integration of social stakes to the management plan. A uses monitoring protocol was developed in this purpose using an ultra light aircraft and a camera. Data on 15 different recreational and non-recreational uses were acquired between 2010 and 2013, flying 48 times a year, and entered into a Geographic Information System. A huge resulting database allowed the building of an initial knowledge of the spatio-temporal distribution of uses within the Reserve. It also enabled the analysis of the uses' evolution regarding various factors of variations (amenities, facilities, shark attacks, tourism, etc.). Finally, we assessed the contribution to management efficiency using social indicators (governance, pressure indicators), and to interdisciplinary research in bringing ecologic and uses data together. This thesis brings a brand new information about coastal human activity and spatio-temporal dynamics of direct pressures on reef. This tool, designed to be reproducible and cost-optimized, enables the production of a set of indicators. Its integration to the management plan exclusively depends on the strategic choices of the manager.
Les récifs coralliens figurent parmi les biomes côtiers les plus emblématiques de la planète. Ces points chauds de la biodiversité mondiale sont convoités par les sociétés humaines pour leurs qualités paysagères et leur plus-value économique. Exposés au même titre que de nombreux écosystèmes côtiers aux changements climatiques (élévation de la température, acidification des océans), ils sont de toutes parts soumis à une anthropisation littorale mal maitrisée (urbanisation, surexploitation des ressources). Dans ce contexte, de plus en plus d' Aires Marines Protégées (AMP) s'établissent sur des écosystèmes anthropisés, les amenant à intégrer l'Homme au coeur de la gestion. À La Réunion où l'urbanisation littorale est dense et où le paysage des usages littoraux ne cesse de s’étoffer, une Réserve Naturelle Marine (RNMR) a été établie en 2007 sur un récif frangeant. L’évaluation de l’efficacité de cette AMP par son gestionnaire doit se faire par le biais d'un ensemble d'indicateurs écologiques et socio-économiques. C’est en vue d’apporter des connaissances sur la fréquentation et les usages pratiqués au sein de la RNMR que cette thèse a été initiée. Elaboré sur la base d'un suivi en ULM, un protocole a été reproduit chaque année entre 2010 et 2013 et a permis la constitution d'une base de données spatialisée, dont l'exploitation a produit trois types de résultats: i) une connaissance initiale de la répartition spatio-temporelle des usages au sein de la RNMR; ii) une compréhension de l'évolution des dynamiques spatio-temporelles à la lumière des facteurs de variations identifiés (aménagements, aménités, crise requin, tourisme, etc.), et iii) une contribution à la gestion par le développement d'indicateurs sociaux (gouvernance, pressions), et à la recherche interdisciplinaire par une confrontation des données de fréquentation et des données écologiques du milieu. La réflexion menée dans le cadre de cette thèse apporte un éclairage nouveau sur les usages et la fréquentation des littoraux coralliens à La Réunion, et leur traduction en termes de pression anthropique directe. Pensé pour être reproductible et optimisé en termes de coût, cet outil permet la production d’un ensemble d’indicateurs dont l’intégration au plan de gestion dépend exclusivement des choix stratégiques du gestionnaire.
https://tel.archives-ouvertes.fr/tel-01308703

Droits : http://creativecommons.org/licenses/by-nc-sa/
tel-01308703
https://tel.archives-ouvertes.fr/tel-01308703
https://tel.archives-ouvertes.fr/tel-01308703/document
https://tel.archives-ouvertes.fr/tel-01308703/file/Th%C3%A8se_Lemahieu.pdf

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Anthropogenic impacts are increasingly affecting the world's oceans. Networks of marine protected areas (MPAs) provide an option for increasing the ecological and economic benefits often provided by single MPAs. It is vital to empirically assess the effects of MPA networks and to prioritize the monitoring data necessary to explain those effects. We summarize the types of MPA networks based on their intended management outcomes and illustrate a framework for evaluating whether a connectivity network is providing an outcome greater than the sum of individual MPA effects. We use an analysis of an MPA network in Hawai'i to compare networked MPAs to non-networked MPAs to demonstrate results consistent with a network effect. We assert that planning processes for MPA networks should identify their intended outcomes while also employing coupled field monitoring-simulation modeling approaches, a powerful way to prioritize the most relevant monitoring data for empirically assessing MPA network performance.
ISSN: 1932-6203

Droits : http://creativecommons.org/licenses/by/
hal-01341695
https://hal-univ-perp.archives-ouvertes.fr/hal-01341695
https://hal-univ-perp.archives-ouvertes.fr/hal-01341695/document
https://hal-univ-perp.archives-ouvertes.fr/hal-01341695/file/journal.pone.0102298.PDF
DOI : 10.1371/journal.pone.0102298

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
1. The use of targets to provide measurable objectives and benchmarks for management, conservation, andrestoration of ecosystems is commonplace. In the marine and coastal realms, targets have been successful insetting sustainable limits to fisheries harvests, thresholds for pollutants, and recommended amounts ofrepresentative habitat included in marine protected area (MPA) networks. Quantifiable targets can dissuadegovernments from making dubious claims about investments in ocean protection that sound impressive butcannot be verified. Examples are presented where protection targets have been used successfully for marinemanagement, and instances where measurable and meaningful benchmarks serve to allow tracking of true progress.2. However, the setting of targets can also be a double-edged sword. In some cases, targets have proven useful,but in many instances, interventions made to fulfil targets not only give a false illusion of progress or even success,they present opportunity costs that impede further conservation.3. Some of these issues were raised in the 2003 article ‘Dangerous Targets?: Unresolved issues and ideologicalclashes around marine protected areas’ that appeared in Aquatic Conservation: Marine and FreshwaterEcosystems. Since its publication, the article’s warnings about how targets can sometimes be dangerous andcounter-productive have led to intense debate among scientists and policy-makers alike, and the paper has beencited in more than 500 publications. Yet today, more than a dozen years after the first ‘Dangerous Targets’publication, new targets are driving more MPA designations and conservation strategies than ever before, andthe ‘dangerous’ aspects of target setting have been largely ignored.4. This paper discusses old ‘dangers’ in the context of new developments in marine conservation, including thelingering problem of having simplistic metrics drive marine policies, and the unintended result that can often occurwhen outputs (percentage of area under MPA designation) do not align with true outcomes of effectivemanagement and conservation. Newly emerging ‘dangers’ in letting areal targets (percentage of area underMPA designation) drive MPA designations are also discussed, including how the rush to fulfil obligations toprotect a certain proportion of area is taking place in planning, separate from broader level, and potentiallymore holistic, marine spatial planning (MSP).5. The paper suggests five recommendations that would allow policy-makers to use targets more effectively,including: (1) increase transparency in planning, especially around specific goals and objectives of MPAestablishment; (2) use time-based areal targets when representativity is a goal of the protected area strategy; (3)
ISSN: 1052-7613

hal-01380963
https://hal-univ-perp.archives-ouvertes.fr/hal-01380963
DOI : 10.1002/aqc.2675

Éditeur(s) : HAL CCSD L'Harmattan
Résumé : International audience
Au terme de la description de la création et de la gestion des grandes aires marines protégées, de l'examen de la situation particulière du Pacifique et de deux cas emblématiques des politiques nationales d'extension de ses zones protégées, peut-on...
Gouvernance, enjeux et mondialisation des grandes aires marines protégées

ISBN : 978-2-343-04160-5
hal-01333476
https://hal-univ-perp.archives-ouvertes.fr/hal-01333476
IRD : fdi:010063183

Éditeur(s) : HAL CCSD
Résumé : International audience
The functioning of the Manche-à-Eau lagoon and of its mangrove environment with the population of marine fish of Guadeloupe has been studied since 1983, and particularly in the 2000s. This ecosystem supports a stable fish assemblage structure because of its twice a day turnover (14.8%) of marine water. It is a favorable and important site for the reproduction (38%) and growth (46%) of a large number of species. The life cycle of these fish species share, for the most part, an ecophase in the mangrove in brackish water and a marine ecophase outside the lagoon. The mangrove plays a vital role in the retention of continental nutrients. This facilitates the trophic exploitation of vegetal and animal detritus bases by the fish in high population density. The majority of populations present individuals reaching length at least 40% from the known maximum length for the species, although only 38.1% have individuals longer than 300 mm. The mangrove aids in the spawning activity of fish species (41% to 58% of the total abundance) and in the reproductive (maturation, migration) process (58% in density and 70% in biomass). The sedentary species lay their eggs in the mangrove, whereas the temporary species stay there during their trophic ecophase or after a genesic migration from the sea to assure sexual maturation for both sexes in the species.
Proceedings of the 61st Gulf and Caribbean Fisheries Institute
Gosier, Guadeloupe

hal-00755780
https://hal.univ-antilles.fr/hal-00755780
https://hal.univ-antilles.fr/hal-00755780/document
https://hal.univ-antilles.fr/hal-00755780/file/GCFI_61_2009_307-312.pdf

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
Symbioses with the dinoflagellate Symbiodinium are widespread among marine invertebrates and protists, especially in nutritionally demanding habitats, such as tropical coral reefs, where they play a major role in ecosystem survival. Moreover, apart from corals and sea anemones, many of the Symbiodinium species and clades involved in these partnerships remain to be characterized. This study provides new insights into nudibranch and sponge associations with Symbiodinium by sequencing regions of the Symbiodinium 28S rDNA and the host mitochondrial COI oxidase. Specimens were sampled between 2011 and 2013 from locations around the islands of Moorea and Tahiti, French Polynesia. Our results revealed that some of the sponges and nudibranchs harbored typical Symbiodinium from clade B or C while others harbored new, undescribed Symbiodinium-like dinoflagellates. A detailed analysis of the different life stages of the nudibranch Phestilla lugubris and of its specific coral prey, Porites rus, suggests a prey-predator horizontal transfer of the symbiont and its vertical inheritance from the parent to the eggs.
Les symbioses à zooxanthelles, dinoflagellés du genre Symbiodinium, sont largement répandues chez les invertébrés marins et les protozoaires, notamment dans les eaux oligotrophes, où ils jouent un rôle important dans la survie des récifs coralliens. De plus, excepté chez les coraux et les anémones, les différentes espèces et clades de Symbiodinium impliqués dans ces associations restent à être caractérisés. Notre étude, grâce à l’utilisation des marqueurs génétiques 28S ADNr des Symbiodinium et la sous-unité 1 de la cytochrome oxydase mitochondriale (COI) de l’hôte, procure de nouvelles données quant aux associations des éponges et des nudibranches avec les Symbiodinium. L’échantillonnage a eu lieu autour de Moorea et de Tahiti (Polynésie française), entre 2011 et 2013. Nos résultats révèlent que certaines espèces d’éponges et de nudibranches possèdent les clades B et C communément retrouvés, chez les coraux notamment, alors que d’autres présentent de nouveaux dinoflagellés « Symbiodinium-like ». Une analyses détaillée des Symbiodinium à différents stades du cycle de vie du nudibranche corallivore Phestilla lugubris et de son corail hôte Porites rus suggèrent l’existence d’un transfert horizontal de Symbiodinium proie–prédateur et un transfert vertical du parent P. lugubris à ses œufs.
ISSN: 1631-0691

hal-01145518
https://hal.archives-ouvertes.fr/hal-01145518
DOI : 10.1016/j.crvi.2015.01.005

Éditeur(s) : HAL CCSD Pacific-credo Publications
Résumé : International audience
Les sciences humaines et sociales dans le Pacifique Sud, terrain questions et méthodes

ISBN : 978-2-9537485-2-9
hal-01342961
https://hal-univ-perp.archives-ouvertes.fr/hal-01342961

Éditeur(s) : Madibenthos
Description : Du 5 septembre au 11 octobre 2016, le Muséum national d'Histoire naturelle a piloté sur les côtes martiniquaises un inventaire de grande ampleur de la faune et de la flore. L'expédition avait pour objectif de renforcer la connaissance actuelle de la biodiversité marine en Martinique par un inventaire quasi exhaustif d'espèces qui sont encore méconnues (algues, éponges, mollusques, crustacés, échinodermes...). Philippe Bouchet, chef de la mission, rappelle dans quel cadre sont menées les grandes expéditions du Muséum. Claude Bouchon évoque ensuite l'évolution des récifs coralliens antillais depuis 30 ans et explique comment les activités humaines impactent cet écosystème riche et fragile. Josiane Pain Mahieu, enseignante au Lycée Montgérald du Marin, qui a participé à la constitution de l'alguier lors de la mission, clôt la conférence en soulignant la nécessité de sensibiliser le jeune public : faire connaître les problématiques de la biodiversité marine de la Martinique aujourd'hui devrait permettre de la préserver demain.
Siècle(s) traité(s) : 21
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V16284
V16284

Éditeur(s) : Elsevier Science Bv
Résumé : Coastal and estuarine systems provide nursery grounds for many marine fish species. Their productivity has been correlated with terrigeneous inputs entering the coastal-estuarine benthic food web, thereby favouring the establishment of fish juveniles. Studies in these ecosystems often describe the nursery as a single large habitat without verifying nor considering the presence of contiguous habitats. Our study aimed at identifying different habitats based on macrozoobenthic communities and morpho-sedimentary characteristics and assessing the trophic interactions between fish juveniles and their benthic preys within these habitats. It included 43 sampling sites covering 5 habitats in which we described taxonomically and quantitatively the invertebrates and fish communities with stable isotopes and gut contents. It suggested that the benthic common sole Solea solea displayed feeding plasticity at the population level, separating the juveniles (G0) from the older fish (G1) into different "feeding sub-populations". Size-based feeding plasticity was also observable in the spatial occupancy of that species in the studied bay. The demersal pouting, Trisopterus luscus, equally used the different habitats but displayed low feeding plasticity across and inside each habitat. Stable isotopes proved to be powerful tools to study the spatial distribution of trophic interactions in complex ecosystems like the bay of Vilaine and to define optimal habitats for fish that use the coastal-estuarine ecosystem as nursery grounds.
Journal Of Sea Research (1385-1101) (Elsevier Science Bv), 2013-08 , Vol. 81 , P. 40-48

Droits : 2013 Elsevier B.V. All rights reserved
http://archimer.ifremer.fr/doc/00151/26226/24327.pdf
DOI:10.1016/j.seares.2013.03.013
http://archimer.ifremer.fr/doc/00151/26226/

Résumé : Les mattes de procaryotes constituent une niche écologique diversifiée. peu étudié!<..en mangrove et jamais décrjte dans les Antilles. L'objectif de cette thèse est de décrire les procaryotes filamenteux reposant sur le sédiment marin et de caractériser les interactions entre la matte, milieu et entre les différents micro-organismes. Nous avons d'abord caractérisé les micro-organismes majoritaires de la matte par le séquençage de l'ADNr 16S et des hybridations moléculaires (FISH). Il a ainsi été possible de décrire deux nouvelles espèces de Beggiatoaceae dont la structure a été étudiée par microscopie électronique. De plus, afin de caractériser l'environnement chimique de ces bactéries, des capteurs potentiométriques ont été utilisés. Ils ont permis de démontrer que les Beggiaotaceae oxydaient les sulfures en prélevant l'oxygène du milieu, tandis que des analyses de microscopie couplées à de l'EDX ont mis en évidence des réserves de soufre intracellulaires dans ces bactéries. Le séquençage de l'ADNr 16S des cyanobactéries filamenteuses a mis en évidence quatre nouvelles espèces de l'ord~e des Oscillatoriales. Deux d'entre elles, du genre Planktothricoides ont révélé une toxicité positive sur les Artemia sp:, les deux autres ont été identifiées comme proches d'Oscillatoria spongeliae, une espèce symbiotique d'éponge, bien que les coupes uItrafines d'une de ces souches aient montré une morphologie interne proche des Tychonema. L'analyse des données a permis d'étoffer les connaissances sur les communautés microbiennes de mangrove et constitue une base intéressante de travail sur la contribution des micro-organismes au fonctionnement de l'écosystème mangrove dans son ensemble
Procaryotic mats are ecological niches, occuring in many ecosystems. Those structures are little studied in marine mangrove sediment and have never been described in West Indies. The purpose ofthis thesis is to characterize the interactions between the mat and the environment, and between the different filamentous micro-organisms living into the mat. In a first place, we characterized the mainly micro-organisrns of the mat by sequencing 16S rDNA. We confirmed these sequences by molecular hybridization (FISH) with specific probes designed from sequences obtained. Thus, it was possible to describe two new Beggiatoaceae strains, whose structure has been studied by electronic microscopy. Furthemore, we used potentiometric captors in situ and in laboratory, by creating a mesocosm, in order to define the chemical environment where involved these bacteria. These experiences proved that the Beggiatoaceae of the mat oxidized the sulfur taking the oxygen from the medium, while the microscopic analysis coupled with EDX showed intracellular sulfur granules into the bacteria. The study of the filamentous cyanobacteria of the mat highlighted four new cyanobacteria strains, all studied by electronic rmcroscopy. Two of them belongs to Planktothrlcoides genus and showed positive toxicity on Artemia salina. The others species are close to Oscillatorla spongeliae, a sponge symbiont, nevertheless, one ofthem showed an intemal morphology close to Tychonema. The analysis of the different results adduces sorne knowledge about mangrove microbial communities. Furthermore, this study can be used as an interesting base to study the micro-organisms contribution in functioning mangrove ecosystem

http://www.theses.fr/2013AGUY0614/document

Éditeur(s) : HAL CCSD Frontiers Media
Résumé : International audience
With global climate change altering marine ecosystems, research on plankton ecology is likely to navigate uncharted seas. Yet, a staggering wealth of new plankton observations, integrated with recent advances in marine ecosystem modelling, may shed light on marine ecosystem structure and functioning. A EuroMarine foresight workshop on the “Impact of climate change on the distribution of plankton functional and phylogenetic diversity” (PlankDiv) identified five grand challenges for future plankton diversity and macroecology research: 1) What can we learn about plankton communities from the new wealth of high-throughput ‘omics’ data? 2) What is the link between plankton diversity and ecosystem function? 3) How can species distribution models be adapted to represent plankton biogeography? 4) How will plankton biogeography be altered due to anthropogenic climate change? and 5) Can a new unifying theory of macroecology be developed based on plankton ecology studies? In this review, we discuss potential future avenues to address these questions, and challenges that need to be tackled along the way.
ISSN: 2296-7745

hal-01545318
https://hal.archives-ouvertes.fr/hal-01545318
DOI : 10.3389/fmars.2017.00068

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
Overfishing and habitat destruction due to local and global threats are undermining fisheries, biodiversity, and the long-term sustainability of tropical marine ecosystems worldwide, including in the Coral Triangle. Well-designed and effectively managed marine reserve networks can reduce local threats, and contribute to achieving multiple objectives regarding fisheries management, biodiversity conservation and adaptation to changes in climate and ocean chemistry. Previous studies provided advice regarding ecological guidelines for designing marine reserves to achieve one or two of these objectives. While there are many similarities in these guidelines, there are key differences that provide conflicting advice. Thus, there is a need to provide integrated guidelines for practitioners who wish to design marine reserves to achieve all three objectives simultaneously. Scientific advances regarding fish connectivity and recovery rates, and climate and ocean change vulnerability, also necessitate refining advice for marine reserve design. Here we review ecological considerations for marine reserve design, and provide guidelines to achieve all three objectives simultaneously regarding: habitat representation; risk spreading; protecting critical, special and unique areas; reserve size, spacing, location, and duration; protecting climate resilient areas; and minimizing and avoiding threats. In addition to applying ecological guidelines, reserves must be designed to address social and governance considerations, and be integrated within broader fisheries and coastal management regimes.
ISSN: 0892-0753

hal-01333534
https://hal-univ-perp.archives-ouvertes.fr/hal-01333534
DOI : 10.1080/08920753.2014.877763

Éditeur(s) : Elsevier
Résumé : Introduction of non-indigenous species can alter marine communities and ecosystems. In shellfish farming, transfer of livestock, especially oysters, is a common practice and potentially constitutes a pathway for non-indigenous introductions. Many species of seaweeds are believed to have been accidentally introduced in association with these transfers, but there is little direct evidence. We experimentally simulated the transfer of oysters from the Thau Lagoon (France). These transfers involved increasing periods of aerial emersion and additional brine and hot water treatments. The brine and hot water treatments were evaluated as a means of reducing the probability of algal introductions with oyster transfers. Shells were cultured for 40 days in experimental tanks to identify the macroalgae likely to be introduced with any oyster transfer. A total of 57 macroalgal taxa, including 16 taxa not indigenous to the Thau Lagoon, were recorded across all treatments and experiments. The abundance of some species increased in several cases following aerial emersion. Elimination treatments (immersion in brine or hot water) significantly reduced algal diversity, with hot water treatments resulting in no species or only tubular Ulva spp. present. The results support the hypothesis that oyster transfers are effective as primary and secondary vectors of macroalgal introductions. Relatively simple changes to the transfer practice (particularly hot water treatments) are suggested as a means of reducing the risk of non-indigenous algal introductions.
Biological Conservation (0006-3207) (Elsevier), 2007-06 , Vol. 137 , N. 2 , P. 237-247

Droits : 2007 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/2007/publication-2779.pdf
DOI:10.1016/j.biocon.2007.02.001
http://archimer.ifremer.fr/doc/00000/2779/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Until recently, our ability to implement and assess spatial marine management approaches has been limited by a lack of information regarding processes that bind marine ecosystems, including habitat locations, larval and adult movement, trophic interactions, and fisher behavior. However, recent advances in habitat-mapping technologies, genetics, marine microchemistry, animal tracking and numerical modeling have greatly enhanced our knowledge of these processes. Although these advances have yet to be fully integrated into management decisions, they have the potential to revolutionize spatial marine management. Nevertheless, this revolution will require advances in our ability to share and integrate data into models of marine ecosystems.
ISSN: 1877-3435

hal-00609464
https://hal.archives-ouvertes.fr/hal-00609464
DOI : 10.1016/j.cosust.2010.02.002

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
Although protists are critical components of marine ecosystems, they are still poorly characterized. Here we analysed the taxonomic diversity of planktonic and benthic protist communities collected in six distant European coastal sites. Environmental deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) from three size fractions (pico-, nano- and micro/mesoplankton), as well as from dissolved DNA and surface sediments were used as templates for tag pyrosequencing of the V4 region of the 18S ribosomal DNA. Beta-diversity analyses split the protist community structure into three main clusters: picoplankton-nanoplankton-dissolved DNA, micro/mesoplankton and sediments. Within each cluster, protist communities from the same site and time clustered together, while communities from the same site but different seasons were unrelated. Both DNA and RNA-based surveys provided similar relative abundances for most class-level taxonomic groups. Yet, particular groups were overrepresented in one of the two templates, such as marine alveolates (MALV)-I and MALV-II that were much more abundant in DNA surveys. Overall, the groups displaying the highest relative contribution were Dinophyceae, Diatomea, Ciliophora and Acantharia. Also, well represented were Mamiellophyceae, Cryptomonadales, marine alveolates and marine stramenopiles in the picoplankton, and Monadofilosa and basal Fungi in sediments. Our extensive and systematic sequencing of geographically separated sites provides the most comprehensive molecular description of coastal marine protist diversity to date.
ISSN: 1462-2912

hal-01191731
http://hal.upmc.fr/hal-01191731
http://hal.upmc.fr/hal-01191731/document
http://hal.upmc.fr/hal-01191731/file/Massana_2015_Marine_protist.pdf
DOI : 10.1111/1462-2920.12955

Éditeur(s) : Université de Guyane
Extrait de : "La gestion durable de l'eau et des milieux aquatiques du bassin de Guyane" : colloque, le 2 juin 2016. Université de Guyane
Description : Présentation de l'exceptionnelle biodiversité de l'espace guyanais.
Siècle(s) traité(s) : 21
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V16211
V16211

Éditeur(s) : Public Library Science
Résumé : Subsurface sediments of the Sonora Margin (Guaymas Basin), located in proximity of active cold seep sites were explored. The taxonomic and functional diversity of bacterial and archaeal communities were investigated from 1 to 10 meters below the seafloor. Microbial community structure and abundance and distribution of dominant populations were assessed using complementary molecular approaches (Ribosomal Intergenic Spacer Analysis, 16S rRNA libraries and quantitative PCR with an extensive primers set) and correlated to comprehensive geochemical data. Moreover the metabolic potentials and functional traits of the microbial community were also identified using the GeoChip functional gene microarray and metabolic rates. The active microbial community structure in the Sonora Margin sediments was related to deep subsurface ecosystems (Marine Benthic Groups B and D, Miscellaneous Crenarchaeotal Group, Chloroflexi and Candidate divisions) and remained relatively similar throughout the sediment section, despite defined biogeochemical gradients. However, relative abundances of bacterial and archaeal dominant lineages were significantly correlated with organic carbon quantity and origin. Consistently, metabolic pathways for the degradation and assimilation of this organic carbon as well as genetic potentials for the transformation of detrital organic matters, hydrocarbons and recalcitrant substrates were detected, suggesting that chemoorganotrophic microorganisms may dominate the microbial community of the Sonora Margin subsurface sediments.
Plos One (1932-6203) (Public Library Science), 2014-08 , Vol. 9 , N. 8 , P. e104427

Droits : This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.
http://archimer.ifremer.fr/doc/00203/31408/29801.pdf
DOI:10.1371/journal.pone.0104427
http://archimer.ifremer.fr/doc/00203/31408/

Éditeur(s) : Springer
Résumé : Because of their characteristic living environments, marine organisms produce a variety of lipids. Fatty acids constitute the essential part of triglycerides and wax esters, which are the major components of fats and oils. Nevertheless, phospholipids and glycolipids have considerable importance and will be taken into account, especially the latter compounds that excite increasing interest regarding their promising biological activities. Thus, in addition to the major polyunsaturated fatty acids (PUFA) such as eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids, a great number of various fatty acids occur in marine organisms, e.g. saturated, mono- and diunsaturated, branched, halogenated, hydroxylated, methoxylated, non-methylene-interrupted. Various unprecedented chemical structures of fatty acids, and lipid-containing fatty acids, have recently been discovered, especially from the most primitive animals such as sponges and gorgonians. This review of marine lipidology deals with recent advances in the field of fatty acids since the end of the 1990s. Different approaches will be followed, mainly developing biomarkers of trophic chains in marine ecosystems and of chemotaxonomic interest, reporting new structures, especially those with biological activities or biosynthetic interest. An important part of this review will be devoted to the major PUFA, their relevance to health and nutrition, their biosynthesis, their sources (usual and promising) and market.
Marine Biotechnology I (0724-6145) (Springer), 2005 , Vol. 96 , P. 49-125

Droits : 2005 Springer-Verlag
http://archimer.ifremer.fr/doc/2005/publication-937.pdf
DOI:10.1007/b135782
http://archimer.ifremer.fr/doc/00000/937/

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Beggiatoaceae, giant sulphur-oxidizing bacteria, are well known to occur in cold and temperatewaters, as well as hydrothermal vents, where they form dense mats on the floor.However, they have never been described in tropical marine mangroves. Here, we describetwo new species of benthic Beggiatoaceae colonizing a marine mangrove adjacent to mangroveroots. We combined phylogenetic and lipid analysis with electron microscopy in orderto describe these organisms. Furthermore, oxygen and sulphide measurements in and exsitu were performed in a mesocosm to characterize their environment. Based on this, two new species, Candidatus Maribeggiatoa sp. and Candidatus Isobeggiatoa sp. inhabiting tropical marine mangroves in Guadeloupe were identified. The species identified as CandidatusMaribeggiatoa group suggests that this genus could harbour a third cluster with organisms ranging from 60 to 120 μm in diameter. This is also the first description of an Isobeggiatoa species outside of Arctic and temperate waters. The multiphasic approach also gives information about the environment and indications for the metabolism of these bacteria. Our study shows the widespread occurrence of members of Beggiatoaceae family and provides new insight in their potential role in shallow-water marine sulphide-rich environments such as mangroves.
ISSN: 1932-6203

hal-01205641
https://hal.univ-antilles.fr/hal-01205641
https://hal.univ-antilles.fr/hal-01205641/document
https://hal.univ-antilles.fr/hal-01205641/file/Beggiatoa%20Plosone2015.pdf
DOI : 10.1371/journal.pone.0117832

Éditeur(s) : HAL CCSD Station Biologique
Résumé : International audience
From fish samplings (rotenone: 6 February 2002 & 13 May 2003; boxtraps: January 2008 to July 2009) in amangrove lagoon, the demographic structure, reproductive period and diet of Lophogobius cyprinoides were studied.Individual fish were measured (< 1 mm), weighed (± 0.01 g), and sexed by observing the urogenital papilla, sex-ratios andtotal length (TL)-standard length and length-mass relationships were calculated. Five individuals per size class (2 mm) wereused to study sexual maturity by macroscopic observation of gonad structure with a sexual maturity scale, and diet byqualitative and quantitative examination of digestive tract contents and calculation of the following indices: levels offullness and vacuity; occurrence, number, and point frequencies of various food items, and quality of nutrition. Growth isisometric and sexual dimorphism in favor of males (78 vs. 64 mm), demographic structure (18 ≤ TL ≤ 78 mm) and conditionevolved over time, with a distinct femininization of the population. Sexual inversion appeared from 46 mm onward, andtotal masculinization at 72 mm. Protogynous hermaphrodism is advantageous in a sedentary, subcryptobenthic species thatis reproductively active almost throughout the year. The species has an omnivorous diet specialized in copepods and plants
ISSN: 0007-9723

hal-00746079
https://hal.univ-antilles.fr/hal-00746079