Dissertationen zum Thema „Mer – Pollution – Indien, Océan“
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Thibault, Margot. „Composition, abundance, origin and distribution of plastic pollution accumulated in the Southern Indian Ocean gyre“. Electronic Thesis or Diss., La Réunion, 2024. https://elgebar.univ-reunion.fr/login?url=http://thesesenligne.univ.run/24_01_M_THIBAULT.pdf.
Der volle Inhalt der QuelleThe majority of mismanaged plastic waste enters the marine environment. Once in the oceans, these plastics drift until reaching subtropical convergence zones, where they accumulate to form “Garbage Patches”. Five zones have been discovered, including one in the southern Indian Ocean. This latter patch has undergone limited surface observation studies, and several predicted models indicate a different location, placing it either west or east of the basin. Supposedly the second most polluted “Garbage Patch” after the North Pacific, it is crucial to identify it for effective intervention accurately. Within this context, the doctoral project aimed to determine the composition, concentration, and origin of plastic debris accumulated in the Southwest Indian Ocean. Since the project's inception, 19 oceanographic campaigns have been conducted to visually monitor macro-debris (> 2.5 cm) and collect microplastics by manta trawl deployment (500 μm – 5 mm). Surveys of marine debris (macro-meso (5 mm – 2.5 cm) beached on uninhabited, remote islands have also been carried out to assess the concentration that does not remain on the surface. Furthermore, a long-term study of plastic pollution was initiated by identifying bio-indicator species in the region. All observations have been compared or complemented with plastic dispersion predictive models in the Indian Ocean. Of all the marine debris collected or observed, 95% consisted of plastics. Among plastics, the predominant subcategory was pre-existing fragmented hard plastics found on the ocean surface, beached on uninhabited islands, and ingested by bio-indicator species. The primary composition of these polymers was polyethylene and polypropylene, and it did not differ between the ocean surface and beaches. A concentration gradient of microplastics was also identified, ranging from 10^3 items.km^-2 at 40°E to 10^5 items.km^-2 at 65°E on latitudes 30/33°S. This gradient has been confirmed by plastic dispersion predicted models, although they tend to underestimate it. In addition, some of the macroplastics stranded on the islands originated mainly from Southeast Asian food packaging. Three species have been identified for long-term monitoring of plastic pollution in the region: loggerhead turtles (Caretta caretta), Barau's petrels (Pterodroma baraui), and tropical shearwaters (Puffinus baillonni). Future studies should include increasing sampling in the central and eastern parts of the Indian Ocean basin during different seasons, studying the impact of plastic debris on associated ecosystems, and developing tailored management solutions
Ouahdi, Rabia. „Paléocéanographie et paléoproductivité liées à la mousson indienne dans le bassin de Somalie, le golfe d'Aden et la mer Rouge durant les derniers 460 000 ans“. Paris, Muséum national d'histoire naturelle, 1997. http://www.theses.fr/1997MNHN0020.
Der volle Inhalt der QuelleBouchon, Claude. „Recherches sur les peuplements de scléractiniaires indo-pacifiques (mer Rouge, océan Indien et océan Pacifique)“. Aix-Marseille 2, 1996. http://elgebar.univ-reunion.fr/login?url=http://thesesenligne.univ.run/H/Bouchon_1996.pdf.
Der volle Inhalt der QuelleLenoir, Séverine. „Complexes neurotoxiques impliqués dans la contamination des produits de la mer de l'Océan Indien : caractérisation toxinique et contribution des toxines de Gambierdiscus toxicus et Ostreopsis mascarenensis“. Paris, Muséum national d'histoire naturelle, 2006. http://www.theses.fr/2006MNHN0006.
Der volle Inhalt der QuelleCiguatera fish poisoning is a food-borne illness endemic to tropical waters where numerous fish are susceptible to accumulate benthic dinoflagellates toxins in their flesh and viscera. In the first part of the work, a study of several regional strains of G. Toxicus associated with a study of several fish vectors of toxins, ciguatoxins have contributed to the improvement of the knowledge on the regional determinism of this ichtyosarcotoxism. The toxinic production by G. Toxicus strain has been confirmed in this area and 9 molecules of gambiertoxins have been detected. The analyse of toxinic profiles of 2 ciguateric species, Lutjanus bohar and Sphyraena barracuda have shown the existence of a variety of ciguatoxins in the south-western Indian Ocean, i) confiming the presence of the major I-CTXs, I-CTX-1 and I-CTX-2 in L. Bohar, ii) revealing the presence of new CTX congeners and iii) a different toxinic profile for S. Barracuda with the supposed presence of Fast Acting Toxins with MW < 900. Palytoxin is one of most potent marine natural product primary isolated from Zoanthids species and is the causative agent of clupeotoxism, severe human seafood poisoning. The multiplicity of severe or fatal human intoxications and emergence of new sources of palytoxin poisoning (fish, crabs, and algae) revealed the complexity of phenomenon of palytoxin poisoning. In the second part, we have characterised toxinic and toxicological profiles of benthic and endemic dinoflagellate from SW Indian Ocean, Ostreopsis mascarenensis. Two analogues of palytoxin have been isolated from this species, the mascarenotoxins. In the absence of sensitive analytical methods for this family of toxin and the revealing of a particular fragmentation of reference palytoxin molecule, a specific analytical method, based on the coupling of the µLC/MS/MS for the detection of palytoxin and palytoxinlike molecules has been developed. To improve, a on-line preconcentration step has been realised
Colonna, Michel. „Chronologie des variations du niveau marin au cours du dernier cycle climatique (0-140 000 ans) dans la partie sud occidentale de l'océan Indien“. Aix-Marseille 1, 1994. http://elgebar.univ-reunion.fr/login?url=http://thesesenligne.univ.run/H/Colonna_1994.pdf.
Der volle Inhalt der QuelleFortilus, Jeanne Marie Rose. „Modélisation bioéconomique des pêcheries thonières : mise en place d'aires marines protégées en haute mer de l'Océan indien“. Nantes, 2012. http://www.theses.fr/2012NANT4023.
Der volle Inhalt der QuelleEn introduction de la thèse, j'expose tout d'abord les enjeux biologiques et économiques de la gestion des pêcheries, puis la problématique des aires marines protégées (AMPs), notamment en haute mer. Dans une seconde partie, la description de la structure en réseau du système bioéconomique a été réalisée: des stocks jusqu'aux di#érents marchés. Je présente ensuite comment la prise en compte de cette structure m'a permis d'homogénéiser les données de captures issues de la base de données Sardara et celles de commerce issues de la base de données Fishstat. Je propose alors une analyse succincte des données homogénéisées. Dans la dernière partie de la thèse, je développe un modèle bioéconomique de l'ensemble de la filière. Ce modèle est basé sur la notion d'équilibre de réseau lequel est reconnu comme de grande taille puis qu'il implique environ 1000 liens biologiques ou économiques. Les algorithmes que j'utilise pour le calcul de l'équilibre du réseau tout en itérant le principe sur plusieurs années sont fournis en annexe. Enfin, je montre que ce travail est capable de développer et d'analyser différents scénarii, de la mise en place d'AMPs au large, entre autres, dont les résultats sont analysés avant de conclure
Boschat, Ghyslaine. „Interannual variability and predictability of the Indian Summer Monsoon : El Niño Southern Oscillation system“. Paris 6, 2012. http://www.theses.fr/2012PA066808.
Der volle Inhalt der QuelleEl Niño-Southern Oscillation (ENSO) and the Indian Summer Monsoon (ISM) are two of the most energetic and influential climatic phenomena on the planet. Although they originate in the tropical Indo-Pacific region, they can extend their reach well beyond, through atmospheric teleconnnections that can affect patterns of climate variability worldwide. This thesis takes part in a global effort to improve our understanding of the potential predictability of ISM rainfall and ENSO, by exploring the large-scale teleconnections associated with the whole monsoon-ENSO system on interannual timescales, as well as the role played by leading modes of coupled variability, particularly in tropical and extratropical parts of the Indo-Pacific region. Based on statistical diagnoses of observations before and after the 1976-77 climate shift, and numerical experiments with the SINTEX-F coupled model, our results highlight the importance of mid-latitudes in the predictability of the ISM-ENSO system. Indeed, significant and robust precursors are identified in the North Pacific and South Indian Oceans during the previous boreal winter/early spring, and have the potential to predict ISM and ENSO events with longer lead-times than their traditional tropical predictors. Besides, this predictability is stronger for the ‘late’ ISM rainfall during August-September. This second part of the ISM season is also characterized by the occurrence of ocean-atmospheric processes in the Indian Ocean, which compete with the effect of ENSO on the monsoon. The enhancement of these local feedbacks could explain the apparent weakening of the seasonal ENSO-monsoon relationship observed in recent decades
Brévière, Emilie. „Variabilités temporelles des flux de CO2 à l'interface air-mer dans l'océan Indien et Austral au sud de la Tasmanie“. Paris 6, 2005. https://tel.archives-ouvertes.fr/tel-00080464.
Der volle Inhalt der QuelleKojadinovic, Jessica. „Écologie trophique de grands prédateurs marins de l'océan Indien occidental tropical par l'étude conjointe de la bioaccumulation d'éléments traces et de rapports isotopiques“. La Réunion, 2006. http://elgebar.univ-reunion.fr/login?url=http://thesesenligne.univ.run/06_17_Kojadinovic.pdf.
Der volle Inhalt der QuelleThis study focuses on thé acquisition of knowledge of various aspects of thé trophic ecology of marine top predators from thé South-Western Indian Océan through thé analysis of trace élément levels and isotopic signatures. Three toxic éléments (cadmium, mercury and lead) and five essential éléments (copper, iron, manganèse, sélénium and zinc) were analyzed in six seabirds (Barau's Pétrel, Audubon's Shearwa'ter, White-tailed Tropicbird, Brown Noddy, Lesser Noddy and Sooty Tern) and five pelagic fishes (Swordfish, Yellowfin Tuna, Skipjack Tuna, Wahoo, Common Dolphinfish). A large range of trace élément levels were observed. Copper levels were high in thé liver of Yellowfin Tunas collected around Reunion Island, rénal iron and zinc levels were high, respectively, in Dolphinfish and Yellowfins sampled in thé Mozambique Channel, and mercury levels were highest in Barau's Pétrels liver and kidney. The large variations of trace élément levels were attributable to a combination of several factors influencing their bioaccumulation: thé organ or tissue considered, thé animais nutritional condition (for essential éléments), thé âge (determined through thé length for fish), thé geographical area, detoxification processes, thé species and thé diet
Duhamel, Guy. „Ichtyofaune des secteurs Indien occidental et Atlantique oriental de l'Océan Austral : biogéographie, cycles biologiques et dynamique des populations“. Paris 6, 1987. http://www.theses.fr/1987PA066349.
Der volle Inhalt der QuelleVallet, Éric. „Pouvoir, commerce et marchands dans le Yémen rasūlide (626-858/1229-1454)“. Paris 1, 2006. http://www.theses.fr/2006PA010704.
Der volle Inhalt der QuelleNurhakim, Subhat. „Biologie et dynamique du Banyar Rastrelliger kanagurta (téléostéen - Scombridae) dans la pêcherie des grands senneurs en mer de Java“. Brest, 1993. http://www.theses.fr/1993BRES2018.
Der volle Inhalt der QuelleLlido, Jérôme. „Variabilité spatiale et temporelle du système biologique dans la convergence subtropicale au sud de l'Afrique“. Toulouse 3, 2004. http://www.theses.fr/2004TOU30208.
Der volle Inhalt der QuelleSouth of South Africa, the greater Agulhas Current system, formed by the Agulhas Front (AF) in close juxtapositon with the Subtropical Front (STF), associated to the Agulhas Return Current (ARC) and the Subtropical Convergence (STC), respectively, and farther south by the Subantartic Front (SAF) is a region of intense mesoscale activity presenting enhanced levels of biological production and chlorophyll a. The spatial and temporal variability of a such frontal system influences the physical/biological interactions. The aim of this work is to examine the spatio-temporal variability of the Aguhas frontal system and to determine how the variability of the thermodynamic fronts (AF, STF, SAF) affects the chlorophyll field and the primary production at seasonal and interannual time scales. A wavelet analysis is performed on the 4-years (October 1997 - September 2001) time series of multi-sensors satellite data sets (ocean colour collected by SeaWiFS, mapped sea level anomalies from Topex/Posei͏̈don-ERS2 and sea surface temperature provided by the infrared radiometer AVHRR) in order to characterize the time and space variability of the front comparing the biological front with the dynamical fronts. A similar analysis is carried out on modelled fields provided by an eddy-permitting, physical-biological coupled model AGAPE-Bio using interannual forcing. Seasonal and interannual variability of the frontal system is then studied through the model results and compared with in situ observations from OISO (Océan Indien Service d'Observation) over the 1998-2001 period. Satellite remote sensing reveals localized high chlorophyll a concentrations, appearing as intermittent event-scale blooms in this region. A statistical analysis is conducted along the Subtropical Convergence to characterize these event-scale blooms in terms of lifetime, chlorophyll concentration, areal extension and spatial distribution. Our numerical model simulates this process with a fair degree of verisimilitude and is used to investigate the physico-biogeochemical requirements for bloom events to occur. We demonstrate that in most cases the limiting factor is intensity of vertical stratification combined with light availability
Tocquer, Flore. „Ozone et transport dans la haute troposphère tropicale de l'océan Indien et de l'Asie du Sud : apport des données spatiales (IASI) et de la modélisation“. Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30033/document.
Der volle Inhalt der QuelleTo better understand the processes controling for the distribution of upper tropospheric (UT) ozone (O3) in the tropics, this thesis examines different aspects of pollution transport from sources regions to UT level, through two case studies that take place in the still debated issues.. First study is based on IASI space observations identified an event of transport of UT enriched O3 air masses from Africa to India. During the pre-monsoon season, events of O3 enrichment in UT above the Indian Ocean were essentially attributed to stratospherics intrusions. Simulations have been used to determine its origin, it excludes a stratospheric origin for the event and indicates a probable important contribution by lightning (LiNOx) that occurs over Africa regions. This study could be extended to the whole region and other seasons with a focus on the spring season in order to complete the conclusions obtained during the INDOEX program. The second part focuses on the characterisation of the impact of a deep convective system upon the UTLS composition during the asian summer monsoon. Simulation with a passive tracer highlights the potential of the convective system located over the central Himalaya foothills, to uplift polluted air masses in UTLS to 100 hPa, where the pollutants are rapidly transported by the asian monsoon anticyclone circulation. In agreement with transport pipe towards the UTLS identified by Bergman et al. 2013. However simulation including reactive chemistry show an overestimation by the model of the amount of LiNOx produced, so an adjustment of their parameterization must be made and sensitivity analysis are foreseen to determine precisely O3 production. This study is established in connection with actual major problematic at the center of general debate of the international collaboration. Like ACAM (Atmospheric Composition and the Asian Monsoon) whose targeting the complexe interaction of asian summer monsoon to atmospheric dynamics and chemistry, as well as climate change impact
Legrand, Brice. „Impact des changements climatiques sur la biodiversité marine tropicale : le cas des oiseaux marins de l’océan Indien occidental“. Thesis, La Réunion, 2016. http://www.theses.fr/2016LARE0043.
Der volle Inhalt der QuelleClimate change will affect terrestrial and marine ecosystems, but the consequences in terms of global biodiversity distribution are still unclear. Studies about selection of marine habitats and trends caused by global warming are growing. The telemetric monitoring provide valuable information on the spatial and temporal variability on distribution of marine predators. All the issues are very important, we have decided to focus on seabirds. The first objective of this thesis project is to study the distribution and selection of foraging habitat of tropical seabirds during their reproductive phase and during their migrations. To characterize the habitat of an abiotic point of view. The second objective of this thesis project is to use scenarios for ocean habitats produced by IPCC to simulate, using habitat models, the temporal evolution of the distribution of suitable habitat. The third objective of this thesis project is to use the available monitoring data to identify "hotspots" of biodiversity. We looked, at first, the puffins Pacific. More particularly, we studied the variations between the different colonies of the same species, from the viewpoint of the distribution, activity and habitat selection. Then we studied the impact of the evolution of climate change on wintering habitat of Barau’s Petrels (Pterodroma baraui). We built habitat selection models. These models were then used to predict the evolution of wintering habitat in 2100, according to different IPCC scenarios. Finally, we have compiled the available telemetry data on seabirds, sea turtles and marine mammals to study the distribution of marine megafauna in the Indian Ocean, and to identify hotspots of high density and high diversity. To establish, in time, protected marine areas
Prodhomme, Chloé. „Impact des températures de surface de l'océan tropical sur la mousson indienne“. Paris 6, 2013. http://www.theses.fr/2013PA066710.
Der volle Inhalt der QuelleThe Indian summer monsoon is a crucial phenomena for India and its 1 billion 200 hundred millions of habitants, because of its strong impact on both agriculture and economy but also of the huge natural disaster, it can bring (drought, floods and land slide). However, our ability to forecast the monsoon is extremely low. This is mainly due to the inability of coupled model to simulate properly the monsoon and its interactions with SSTs (Sea Surface Temperature) of the different basins. The thesis falls in with the strong research effort to improve our ability to simulate the monsoon and its interactions with the different oceanic basins. In this way, with the help of a global coupled ocean-atmosphere model, of a forced atmospheric atmosphere model and of many sensitivity experiments, we have tried to understand the exact role of tropical ocean on the monsoon and its onset, both in term of mean state and interannual variability. In term of mean state, we have shown that the Indian Ocean SSTs control the amplitude of the monsoon but not the spatial repartition of monsoon rainfalls and its onset date. In the same way, the Indian Ocean seems to have mainly a passive role on the monsoon at the interannual time scale. Conversely, both in term of mean state and interannual variability, the Indian Ocean seems strongly impacts Pacific Ocean SST. Moreover, the Pacific Ocean plays a crucial role on the monsoon and its onset. A correct representation of Pacific mean SSTs seems indispensable to properly simulate to the monsoon onset date
Bihr, Stéphane. „Les serpents venimeux marins“. Paris 5, 1995. http://www.theses.fr/1995PA05P218.
Der volle Inhalt der QuelleBreviere, Emilie. „Variabilités temporelles des flux de CO2 à l'interface air-mer dans l'océan Indien et Austral au sud de la Tasmanie“. Phd thesis, Université Pierre et Marie Curie - Paris VI, 2005. http://tel.archives-ouvertes.fr/tel-00080464.
Der volle Inhalt der QuelleLa région subantarctique (43-53°S) est un puits intense de CO2 au printemps comme en été et la variabilité interannuelle n'y semble pas significative.
La région située au sud de 62°S présente une forte variabilité spatio-temporelle due en grande partie à l'influence des glaces.
La zone ouverte de l'océan Austral (POOZ) présente la variabilité estivale interannuelle la plus importante: En février elle est presque à l'équilibre en 1997 (–0.3 mmol.m-2.j-1) et présente un puits intense en 2003 (–20.6 mmol.m-2.j-1). Une augmentation de la biomasse phytoplanctonique est à l'origine de ce puits. L'exploitation de différents paramètres révèle que l'augmentation de biomasse n'a pas pu être favorisée par une augmentation de SST, ni par un régime mélange/lumière ou par un contenu intégré d'ozone stratosphérique différents. Par contre, les processus à l'origine de cet accroissement semblent être liés à la présence d'un évènement ENSO en 2002/03 et à des apports de fer épisodiques provenant d'Australie.
Filliozat, Manonmani. „L'océan oriental : connaissances hydrographiques françaises aux XVIIe et XVIIIe siècles“. Paris, EPHE, 2002. http://www.theses.fr/2002EPHE4036.
Der volle Inhalt der QuelleJouandet, Marie-Paule. „Impact d'une fertilisation naturelle en fer sur le cycle du carbone océanique (Iles Kerguelen, Océan austral)“. Aix-Marseille 2, 2008. http://www.theses.fr/2008AIX22096.
Der volle Inhalt der QuelleResplandy, Laure. „Impacts biogéochimiques des processus de haute fréquence à l'échelle régionale et saisonnière“. Paris 6, 2010. http://www.theses.fr/2010PA066089.
Der volle Inhalt der QuelleCuvillier, Alexis. „Dynamique et fonctionnement des herbiers marins dans un complexe récifal anthropisé (île de la Réunion, océan Indien)“. Thesis, La Réunion, 2016. http://www.theses.fr/2016LARE0037/document.
Der volle Inhalt der QuelleLocated at the benthos-pelagos interface, seagrass beds have many ecosystemic roles such as coastal protection or biodiversity. Historically, scientists and decision-makers at Reunion Island have been focusing on reef ecosystems. However, for several decades, monospecific (Syringodium isoetifolium) seagrass beds have been observed (3 hectares – 2013) within Ermitage / La Saline reef (West coast). The main objective of this study was to give the first data on seagrass ecology at Reunion Island. Therefore, a multi-disciplinary study was developed. First, seascape ecology of seagrasses is analyzed at decadal (since 1950) and seasonal scales (2013-2015). Physical settings (swell) and eutrophication were driving factors on the spatial dynamics of seagrass beds. Second, seagrass community metabolism and response to nutrient loads (nitrate and phosphate) show variations in metabolic budget (autotrophy to heterotrophy) and make seagrass beds a nutrient sink following the environmental conditions. Third, stable isotope analysis (δ13C and δ15N) identified sources of particulate matter entering the ecosystem and fueling food webs. The trophic roles of seagrass beds are assessed for echinoderm and herbivorous fish communities. This study highlighted a trophic link between seagrass and Holothuria leucospilota, and proved some species to be heavily dependent on seagrass ecosystem (Leptoscarus vaigiensis, Siganus sutor). Finally, interviews showed a lack of knowledge about this ecosystem despite crucial economic and ecologic roles. Considering their major functions, seagrass beds have to be considered in future management of the coastal marine systems at Reunion Island
Jaquemet, Sébastien. „Rôle des oiseaux marins tropicaux dans les réseaux trophiques hauturiers du Sud-Ouest de l'océan Indien“. La Réunion, 2005. http://tel.archives-ouvertes.fr/tel-00464182/fr/.
Der volle Inhalt der QuelleTropical seabirds show a hierarchical distribution depending on the position of their colonies and their dispersion capability. At macro-scale it reflects the boundaries of their habitats, at meso-scale the presence of structures aggregating prey, and at micro-scale the presence at the surface of prey driven by predatory schools. In the South-West Indian Ocean, more than 6 millions of birds are present, of which 99% are sooty terns. They breed seasonally in austral winter in the Seychelles and at Europa, in austral summer at Juan de Nova. The high chlorophyll concentration around colonies favours the development of food web leading to the terns. The location of Glorieuses favours a sub-annual breeding regime, led by the presence of prey around the colony all year round. Biomass removed by terns in the Mozambique Channel is estimated to 55,000 tons, by breeding season
Minvielle, Fanny. „Aspects physiques et radiatifs du cycle atmosphérique des aérosls : étude numérique sur l'Océan Indien(expérience INDOEX)“. Clermont-Ferrand 2, 2003. http://www.theses.fr/2003CLF22246.
Der volle Inhalt der QuelleDencausse, Guillaume. „Échanges indo-atlantiques d’eau subtropicale en relation aux structures frontales et de mésoéchelle : utilisation de la série temporelle altimétrique de niveau de la mer“. Brest, 2009. http://www.theses.fr/2009BRES2051.
Der volle Inhalt der QuelleIndo-Atlantic exchanges of subtropical water play a crucial role in controlling global climate. The intense mesoscale activity south of Africa contributes to these exchanges, yet remains poorly described. A commonly accepted circulation scheme of those waters assmues that the subtropical gyres of the neighbouring oceans are partially connected, forming a super-gyre. Using an altimeter-derived sea-level time series spanning over 12 years, we study the exchanges through the “northern branch” of the super-gyre (Indian to Atlantic ocean), and through the “southern branch” (opposite direction). Regarding the northern branch, an initial study of the Agulhas Current Retroflection yields a statistical description of its behaviour, and shows the disrupting role of local bathymetry. Then, a thorough tracking of all Agulhas Rings trajectories shed by the Retroflection yields 3 typical paths, linked to regional bathymetry, whose contributions to inter-ocean exchanges are evaluated. Applying the same methods to regional simulations shows inadequate behaviour of the Retroflection and ring trajectories. Exchanges through the southern branch of the super-gyre could be associated with the a jet-like flow of the Subtropical Front, the question of its continuity thus being crucial. If the front seems continuous in the mean sea level field, applying the method developed to locate the mean front to weekly SSH fields shows that mesoscale features west of the retroflection strongly disturb its path, making it discontinuous. Exchanges mechanisms through this branch are thus probably more complex
Bhugwant, Chatrapatty. „Étude physico-chimique des aérosols de combustion et de l'ozone troposphérique à la Réunion“. La Réunion, 2001. http://elgebar.univ-reunion.fr/login?url=http://thesesenligne.univ.run/01_16_Bhugwant.pdf.
Der volle Inhalt der QuelleDuflot, Valentin. „Quantification et étude du transport des polluants dans la troposphère tropicale de l'océan Indien“. Phd thesis, Université de la Réunion, 2011. http://tel.archives-ouvertes.fr/tel-00671951.
Der volle Inhalt der QuelleDauchy, Xavier. „Spéciation des butylétains dans les sédiments marins par couplage chromatographie en phase liquide - plasma à couplage inductif/spectrométrie de masse (HPLC-ICP-MS)“. Pau, 1993. http://www.theses.fr/1993PAUU3003.
Der volle Inhalt der QuelleVéron, Alain. „Dynamique du transfert du plomb dans l'océan atlantique Nord-Est depuis l'atmosphère jusqu'au sédiment“. Paris 11, 1988. http://www.theses.fr/1988PA112025.
Der volle Inhalt der QuelleCrochelet, Estelle. „Modélisation de la connectivité larvaire et implications en terme de gestion de l'environnement“. Thesis, La Réunion, 2015. http://www.theses.fr/2015LARE0003/document.
Der volle Inhalt der QuelleIntegrating ecological connectivity into marine ecosystem management and planning is important, especially in a global context of severe fish stocks depletion and growing habitat degradation. Environmental tools such as Marine Protected Areas have been proposed to protect biodiversity, restore damaged ecosystems, sustain fisheries, and rebuild overexploited stocks. The effectiveness of marine protected areas depends in part on the maintenance of connectivity between marine populations, linked by ecological processes such as larval dispersal. In this thesis, we applied a biophysical model driven by ocean currents derived from satellite altimetry to evaluate connectivity between Western Indian Ocean reefs and across the current MPA system in the Mediterranean Sea. We applied different methods of analysis such as graph-theoretic and clustering. In the Western Indian Ocean, marine connectivity analyses show that the number of connections between reefs increases with fish pelagic larval duration. It also highlights a low connectivity across the region and a high interconnectivity within several regions (Mozambique Channel, Mascarene archipelago). In the Mediterranean Sea, connectance is globally low at the regional scale. This connectance is more important in Western than Eastern Mediterranean. Moreover, the marine connectivity analyses revealed high domestic connectivity rates. Depending on the study area, priority reefs or sites for MPA implementation are proposed. Finally, implications for transboundary marine policies and regional cooperation are discussed
Saxcé, Ariane de. „Commerce, transferts, réseaux : des échanges maritimes en mer Erythrée entre le IIIe s. av. n.è. et le VIIe s. de n.è“. Thesis, Paris 4, 2015. http://www.theses.fr/2015PA040028.
Der volle Inhalt der QuelleThis dissertation deals with the maritime connections that took place between South Asia (South India and Sri Lanka) and the Mediterranean world between the 3rd c. BCE and the 7th c. CE. It first establishes a global account of the archaeological remains found in South Asia that show the importation of Mediterranean products into this area, by comparison with other types of sources (texts, inscriptions, coins). The study then proceeds towards the social and cultural impact that these imported goods may have had on local populations, with regard to their proper way of appropriating foreign sources of inspiration depending on the regional context. Lastly, attention has been drawn on the return flow of goods from East to West, through archaeological vestiges located on the coasts of Egypt, Africa, Arabia and in the Persian Gulf. This leads to a reassessment of the global quantity of commercial goods crossing this large area, which may have been inferior to what was previously considered, whereas the social and cultural impact is not to be denied. The full picture of these interactions gives an image of a very intricate and complex network, involving lots of intermediaries, middlemen and local networks, which would have created a strong background for the direct long-distance links
Le, Ster Loïc. „Estimation des variations saisonnières et interannuelles de la biomasse et de la composition en phytoplancton du secteur indien de l’Océan Austral sur les deux dernières décennies et évaluation de leurs conséquences écologiques“. Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS429.
Der volle Inhalt der QuelleThe Southern Ocean (SO) plays a critical role in the uptake and storage of anthropogenic carbon due to the combined action of physical and biological pumps (Boyd et al. 2019 DOI:10.1038/s41586-019-1098-2). Furthermore, the Southern Ocean provides half of the primary production of the biosphere. Recent analyses nevertheless suggest a change in surface chlorophyll-a (Chl-a) concentrations in the Southern Ocean with an increasing trend, especially over the winter period (Del Castillo et al. 2019 DOI:10.1029/2019GL083163). Given the phenology of the different phytoplankton species, this trend and the associated temporal shift could imply a change in the composition of phytoplankton communities succeeding each other during the year. This hypothesis is supported, but not verified, by work done at the CEBC revealing a continuous decrease in the δ13C isotopic signature of Kerguelen elephant seals over the period 2006-2018 while the signature of dissolved inorganic carbon (DIC) did not vary over the same period (SNO-OISO data, N. Metzl personal comm.). This change in elephant seal composition reflects a potential change in the quality of phytoplankton at the base of the food chains on which they depend (Schell et al., 1989 DOI:10.1007/BF00399575; Cherel and Hobson, 2007 DOI:10.3354/meps329281). The objective of the project is firstly to estimate quantitative variations in phytoplankton biomass in the Indian sector of the Southern Ocean, and secondly, to assess the associated qualitative changes in phytoplankton community composition, as well as their impacts on the ecology of large predators such as the elephant seal
Thomassin, Aurélie. „"Des réserves sous réserve" : acceptation sociale des Aires Marines Protégées : l'exemple de la région sud-ouest de l'océan Indien“. Phd thesis, Université de la Réunion, 2011. http://tel.archives-ouvertes.fr/tel-00627993.
Der volle Inhalt der QuellePichon, Emmanuel. „Recherche de molécules naturelles bioactives issues de la biodiversité marine de la zone sud-ouest de l'océan Indien“. Thesis, La Réunion, 2016. http://www.theses.fr/2016LARE0018/document.
Der volle Inhalt der QuelleThe work described in this manuscript concerns four sponges from the South-West Indian Ocean: Plakortis kenyensis, Theonella swinhoei, Haliclona fascigera and Fascaplysinopsis reticulata. The chemical study of the sponges including extraction, isolation and identification of secondary metabolites was undertaken using various chromatographic (MPLC, HPLC ...) and spectroscopic (UV-visible, HRMS, 1D and 2D NMR ...) techniques. Twelve secondary metabolites including six new molecules were isolated from these sponges. The new molecules are: 2,5-époxydocosan-6-en-21-ynoic acid (HF1) an unusual fatty acid isolated from the sponge Haliclona fascigera; 8-oxo-tryptamine (FR2), 6,6'-bis (debromo)-gelliusine F (FR3), 6-bromo-2'-demethyl-3'-N- methyl-1',8-dihydroaplysinopsine (FR6), 5,6-dibromo-2'-demethyl-3'-N-methyl-1',8-dihydroaplysinopsine (FR7) and 5,6-dibromo-3’-deimino-2’-demethyl-3’-oxo-1’,8-dihydroaplysinopsine (FR8), five indole alkaloids isolated from the sponge Fascaplysinopsis reticulata. The biological activities of the isolated molecules were then evaluated. Among the twelve isolated molecules, seven were active against the malaria parasite Plasmodium falciparum, three were identified as inhibitors of the quorum sensing-regulated bioluminescence in Vibrio harveyi and five, showing marine bacterial adhesion and/or growth inhibition, exhibited potential anti- microfouling activity
Renault, Lionel. „Impact des jets côtiers atmosphériques sur l'Upwelling du système de courants de Humboldt“. Toulouse 3, 2008. http://thesesups.ups-tlse.fr/465/.
Der volle Inhalt der QuelleThe objective of this thesis is to study the impact of atmospheric Coastal Jets on the upwellings of the Humboldt Currents System. A double approach is used: the first one consists in studying the Atmospheric and Oceanic Circulation as well as the Ocean/Atmosphere interactions from the observations, whereas the second aims at modeling these Circulations in a realistic way by means of numerical regional models (ROMS for the ocean modeling and WRF for the atmosphere modeling. The obtained results suggest that there are various Atmospheric Coastal Jets along the Chilean and Peruvian Coasts. For certain ranges of frequencies, they control the upwelling variability of Chile and Peru. A heat flux balance of the Ocean Mixing Layer allows to identify the main mechanisms which control the oceanic answer off Central Chile. Moreover, we show that the Peruvian coast is under the influence of the both local atmospheric forcing and remote forcing. At some frequencies, the Kelvin wave trapped to the Peruvian Coasts induce a control of the coastal ocean variability by the Equatorial variability. The atmospheric regional model reproduces with realism the Chilean Coastal Jets whereas it has difficulty in simulating the atmospheric circulation at the level of Peru. The oceanic simulations reproduce the oceanic answer to the Coastal Jets off Central Chile. A heat flux balance of the Mixing Layer allows us to study what are the main mechanisms which control the oceanic answer in the model. Finally, we show that the regional models present a sensibility to the spatial resolution of the atmospheric and oceanic models. In particular, close to the coast, the wind characteristics in the atmospheric model depends on the spatial resolution of the model. This sensibility induce that the oceanic answer depends on the forcing field spatial resolution. .
Roux, Vincent. „Droit de l'environnement et développement durable dans une collectivité territoriale française d'Outre-Mer : le cas de Mayotte“. Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM1105/document.
Der volle Inhalt der QuelleIn what measure does the legal status of a region with a measure of autonomy allow a better consideration of the right(law) of the environment and does it favor the sustainable development of a territory? The evolution of the legal status of Mayotte towards the status of department has numerous legal consequences. The passage of the principle of legislative speciality in that of legislative identity obliges Mayotte to adapt its right(law) sometimes in a very important way. Numerous pieces of the right(law) are concerned. Among them the right(law) of the environment holds a place(square) part because it is one of the components fundamental of the sustainable development of the territory. From this point of view, the departmIn what measure does the legal status of a region with a measure of autonomy allow a better consideration of the right(law) of the environment and does it favor the sustainable development of a territory? The evolution of the legal status of Mayotte towards the status of department has numerous legal consequences. The passage of the principle of legislative speciality in that of legislative identity obliges Mayotte to adapt its right(law) sometimes in a very important way. Numerous pieces of the right(law) are concerned. Among them the right(law) of the environment holds a place(square) part because it is one of the components fundamental of the sustainable development of the territory. From this point of view, the departmIn what measure does the legal status of a region with a measure of autonomy allow a better consideration of the right(law) of the environment and does it favor the sustainable development of a territory?
Sabino, Magali. „Bioaccumulation of trace elements in Seychelles marine food webs“. Thesis, La Rochelle, 2021. http://www.theses.fr/2021LAROS026.
Der volle Inhalt der QuelleFood security, that is guarantying food supply and quality while sustainably managing resources, is closely linked to knowing the biology and ecology of consumed species. In a context of global changes that are threatening seafood safety, it is thus necessary to establish baselines on marine ecosystem functioning, as well as nutrient availability and contamination occurrence in seafood. This is all the more important in Small Island Developing States (SIDS), where populations rely on marine resources for their subsistence, and where capture fisheries resources are the main sources of proteins and micronutrients (i.e. essential trace elements) in local populations’ diet. In spite of the importance of tropical systems in ensuring food security, they remain largely understudied compared to polar and temperate systems. This thesis thus aims to better understand the functioning of tropical marine systems, and to establish a baseline on micronutrient availability and metal(loid) contamination in a wide diversity of capture fisheries resources from the Seychelles (Western Indian Ocean), a tropical SIDS. By investigating trace element concentration patterns at the inter- and intraspecific levels, it was possible to identify intrinsic and extrinsic factors influencing trace element bioaccumulation in tropical capture fisheries resources. We thus highlighted the importance of considering different scales (individual, species, and ecosystem) to better understand essential trace element availability and non-essential trace element occurrence in seafood
Corbeau, Alexandre. „Relations entre oiseaux marins et pêcheries : Albatros sentinelles de l’océan Austral“. Thesis, La Rochelle, 2020. http://www.theses.fr/2020LAROS021.
Der volle Inhalt der QuelleThe current 6th major species extinction crisis is also affecting seabirds, especially albatrosses. Their populations have decreased by 70% over the last 60 years, mainly due to mortality in longline fisheries. Large albatrosses cover enormous distances during their foraging trips and their curiosity and opportunism favour regular encounters with boats. Thus, they constitute privileged models for studying the relationships between seabirds and fisheries. During the course of this thesis, thanks to the development of new prototype loggers deployed on Wandering and Amsterdam albatrosses in the Indian Ocean and new methods for estimating by-catch risks, we were able to observe that natural foraging behaviours differ from those associated with a boat. Similarly, the intrinsic characteristics of birds (species, population, sex, age and personality) lead to differences in exposure to by-catch risk, particularly through the use of different habitats. Finally, we have shown that the characteristics of boats also have a strong influence on the risk of by-catch, in particular through the type of boats encountered, their legality, the fishing practices used and the presence of discards. We conclude by presenting new methods to better estimate the risks of by-catch and the need for fundamental knowledge of species and populations in order to better protect marine environments that are increasingly endangered
Bachari, Houma Fouzia. „Modélisation et cartographie de la pollution marine et de la bathymétrie à partir de l'imagerie satellitaire“. Phd thesis, Université Paris-Est, 2009. http://tel.archives-ouvertes.fr/tel-00504378.
Der volle Inhalt der QuelleCampos, Pierre-Éric. „Biodiversité des invertébrés marins : de l'isolement à la modélisation moléculaire de métabolites secondaires pour la découverte de nouveaux candidats médicaments“. Thesis, La Réunion, 2017. http://www.theses.fr/2017LARE0007/document.
Der volle Inhalt der QuelleThe work described in this manuscript concerns the chemical study of four sponges from Madagascar: Monanchora unguiculata, Amphimedon sp., Aulospongus gardineri and Biemna laboutei. For the first three sponges, the study was devoted to the extraction, isolation and identification of secondary metabolites by various chromatographic (MPLC, HPLC…) and spectroscopic (UV, HRMS, 1D and 2D NMR…) techniques. Fitfteen secondary metabolites including guanidine alkaloids, bromotyrosin derivated, N-acylethanolamines and polyynes were isolated from these sponges. Eight are new molecules. The biological activities of the isolated compounds were then evaluated. Two of them, fromiamycalin (M70) and ptilomycalin F (MU7) showed a very good antimalarial activity and four of them, fromiamycalin (M70) and ptilomycalins E (MU6), G (MU8) and H (MU9) a promising cytotoxicity against KB cells. The study of the last sponge, Biemna laboutei, was performed on molecules already isolated in the LCSNSA. This work included the determination of the relative configuration of nine guanidine alkaloids by using the DP4+ probability. The relative configuration of seven molecules was confirmed. Three of them, netamines G (E8), P (E17) and R (E19) were selected for a study by molecular modeling to determine their absolute configuration by comparison of their experimental Electronic Circular Dichroism spectrum with a calculated spectrum
Brussieux, Marc. „Reconnaissance des formes et cartographie des nappes d'hydrocarbures par traitement numérique d'images de télédétection“. Paris 6, 1986. http://www.theses.fr/1986PA066499.
Der volle Inhalt der QuellePétriat, Philippe. „Les grandes familles marchandes hadramies de Djedda, 1850-1950“. Thesis, Paris 1, 2013. http://www.theses.fr/2013PA010641.
Der volle Inhalt der QuelleThis work adresses the history of Hadrami merchant families settled in Jeddah from 1850 to 1950, a group that is still well-known for its economic role in the Hejaz and Saudi Arabia,. Built on private, Ottoman and European archives, it describes a specific group of the Ottoman provincial notability and of the Hadrami diaspora. As soon as the 1850s, their being part of Jeddah's notability was the result of three main factors : their success in adapting family agency to an extensive network of trade, their role in the local Hadhrami community, and their integration into the business group of the city. In the 19th century, Jeddah was Meccas harbor and a platform for trade between India, the East-African coast and Egypt. In this way, the history of these farnilies from Hadhramaut was closely related to the economic and political history of Hejaz. It brings back the history of the Hejaz in its global context, evidencing the connections between the Mediterranean and the Indian Ocean. Changes in these merchants' activities and in the composition of their group paralleled the changes in the economic and political situation of the Hejaz, which was successively a province of the Ottoman Empire and a Sharifian Emirate, the Hashemite Kingdom in 1916 and the western region the Saudi Kingdom from 1925 onwards. During the 1930s and the 1940s, the gradual disappearance of these traders from the economic elite of the country, and the emergence of other Hadrami business men, illuminate the impact of new directions of trade and regional migrations, that proved as important as the new political regime and the beginning of oil wealth