Teses / dissertações sobre o tema "Habitats artificiels à poissons"
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Bouchoucha, Marc. "Les zones portuaires peuvent-elles servir de nourriceries alternatives pour les poissons marins côtiers ? : cas des sars en Méditerranée Nord-occidentale". Thesis, Perpignan, 2017. http://www.theses.fr/2017PERP0046/document.
Texto completo da fonteDuring their life cycle, most of the marine coastal fish species use nursery grounds which quality influence their recruitment and then the conservation of their populations. However, the construction of ports impair irremediably fish nursery function of the coastal areas impacted. The ultimate aim of the PhD research was to assess if ports could provide suitable alternative nursery habitats for coastal fish species. Firstly, abundances of the juveniles of four Diplodus species were surveyed in five marinas located along the French Mediterranean coast. This showed that coastal fishes can successfully settle and grow inside these artificialized coastal areas. Moreover, increasing the complexity of port habitats can considerably enhance their suitability for juveniles, especially at the youngest stages. Secondly, body condition, growth rate and metal contamination in the juveniles of two Diplodus species (D. sargus and D. vulgaris) were compared between different ports and natural areas in the Bay of Toulon. Juvenile growth and condition can be equivalent between fish collected from ports and from adjacent natural areas. Contamination levels in fish were low, even in highly polluted areas. Finally, otolith composition in the juveniles of D. sargus and D. vulgaris was investigated in three ports and two natural areas in the Bay of Toulon. None of the port related had systematically higher concentrations in otoliths from Diplodus juveniles collected in ports. Therefore, otolith microchemistry cannot provide a unique and reliable fingerprint discriminating ports and natural areas. Nevertheless, otolith microchemistry could provide an effective natural tag to determine the contribution of ports to adult stocks provided that a library of all potential juvenile habitat fingerprints is established. All these results confirm that ports can be used as alternative nursery habitats by marine coastal fishes. Ecological engineering projects aiming at increasing structural complexity of port habitats seem promising for biodiversity and fish stock conservation
Varenne, Alix. "Étude de la diversité des nurseries artificielles dans les zones portuaires et de leur connectivité trophique avec les écosystèmes adjacents". Electronic Thesis or Diss., Université Côte d'Azur, 2024. http://www.theses.fr/2024COAZ5044.
Texto completo da fonteCoastal development modifies shorelines by introducing man-made habitats, which significantly impact coastal biodiversity and ecosystem functioning. Ecological engineering solutions, such as artificial fish habitats (AFH), can help rehabilitate extremely modified areas, including ports, by offering shelter for fish. As a side effect, AFH provide a substrate to benthic invertebrates and macroalgae, that could improve ecosystem functioning. The effects of AFH may also extend beyond ports and modify trophic exchange with adjacent habitats via fish feeding hydrodynamics. This thesis investigates the patterns of distribution of invertebrate biodiversity associated with AFH and explores the exchange of biomass between marinas and adjacent Posidonia oceanica meadows along the French Mediterranean coast where these habitats are often adjacent.The objectives are: (1) evaluating how taxonomic diversity and composition of benthic invertebrates vary with AFH immersion time, (2) understanding how AFH types and environmental context modify benthic assemblages, and (3) exploring the exchanges of organic matter between marinas and adjacent meadows. I focused on Biohut® AFH (ECOCEAN), made of a metal cage filled with oyster shells, attached to docks or under pontoons in harbours and marinas.In chapter 1, I examined the role of immersion time in determining the diversity and composition of invertebrate assemblages colonising AFH in 3 commercial harbours. The findings indicated significant variations in invertebrate composition from 6 to 18 months, with increased abundance, taxonomic richness, and evenness over time. In chapter 2, I focused on the geographical and within-port variability in taxonomic composition and diversity of invertebrates dwelling in AFH. The study revealed differences in taxa composition between 2 large regions, characterised by different nutrient loads and correlations between assemblage composition and chlorophyll-a, a proxy for nutrient concentration. The number of taxa was the highest in the nutrient-enriched region. Additionally, invertebrate assemblages varied according to port habitats where the AFH were placed, possibly due to differences in light availability. In chapter 3, I investigated trophic connectivity between P. oceanica meadows and adjacent marinas at 4 sites where both habitats are present. Two marinas were equipped with AFH and the remaining 2 were not. At the unequipped sites, the δ15N values of the particulate organic matter within the marina were the highest indicating human-derived nutrient enrichment. The values decreased within the meadow, gradually according to the distance. This suggests a spill of nutrients over the portion of the meadow adjacent to the inlet. Fish relied on resources from both the seagrass meadow and the marina, similarly among the 4 sites, however, the trophic niches of fishes (Diplodus spp.) captured within the equipped marina were slightly larger than those within unequipped ones and overlapped less with the trophic niches of the fish captured outside. Fish faeces were also part of the organic matter sedimenting within meadows. In chapter 4, I reported initiatives developed with other scientists. They include species functional diversity and trophic relations within AFH, acoustic signatures of organisms dwelling in AFH and biodiversity comparison between ports and marine reserves using environmental DNA.My work has highlighted several aspects that could improve the effectiveness of AFH as ecological engineering solutions. Immersion time, local environmental conditions, and specific locations within ports need particular attention. Although I did not find clear differences in cross-habitat exchange related to AFH, they seemed to play a role in reducing nutrient enrichment. Moreover, since fish play an important role in cross-habitat exchanges and find refuge within AFH, this ecological engineering solution could indirectly contribute to change trophic connectivity
Lamontagne, Denis. "Habitats de quelques espèces de poissons riverains du lac Saint-Pierre, Québec". Thèse, Université du Québec à Trois-Rivières, 1988. http://depot-e.uqtr.ca/5760/1/000569515.pdf.
Texto completo da fonteCheminée, Adrien. "Ecological functions, transformations and management of infralittoral rocky habitats from the North-western Mediterranean : the case of fish (Teleostei) nursery habitats". Nice, 2012. https://tel.archives-ouvertes.fr/tel-01223518.
Texto completo da fonteCette thèse avait pour objet les habitats de l’Infralittoral rocheux Méditerranéen qui ont un rôle de nourricerie pour les juvéniles de poissons (Téléostéens). Cette étude visait à mieux comprendre leurs caractéristiques et les conséquences de leurs transformations, notamment d’origine anthropique, dans le but de rassembler des données utiles à la gestion des zones côtières. Au sein de la mosaïque paysagère sous-marine, parmi les faciès de la biocénose des macrophytes photophiles de la roche infralittorale, les forêts de Cystoseires forment un habitat à macrophytes arborescentes qui est menacé. Cette thèse a démontré que ces forêts abritaient des densités plus élevées de juvéniles de poissons (notamment Labridae et Serranidae) que celles observées au sein de faciès alternatifs, en particulier les brousses à Dictyotales et Sphacelariales et les faciès de surpâturage. La haute valeur relative de nourricerie, que ce soit des forêts de Cystoseires (pour trois espèces du genre Symphodus), ou des petits fonds à blocs et galets (pour les espèces du genre Diplodus), a été observée de manière récurrente dans les différents sites littoraux étudiés aussi bien à l’échelle locale (1 km) que régionale (20 à 100 km). Cependant, pour un habitat donné, les densités de juvéniles ont montré une forte variabilité spatiale entre sites. La variabilité spatiale des densités de juvéniles, aussi bien entres sites des forêts à Cystoseires que d’un habitat à l’autre, était notamment associée aux différences de structure tridimensionnelle de l’habitat (hétérogénéité et complexité). Cette structuration fournissait un refuge pour les juvéniles et a en particulier influencé l’efficacité de leurs prédateurs. Ces travaux, sur la base de manipulations expérimentales et d’observations in situ, ont démontré que les transformations des habitats, telles que la fragmentation des forêts ou la diminution de la densité de leur couverture, réduisaient drastiquement leurs valeurs de nourricerie pour les poissons côtiers. Ces résultats suggèrent que la productivité en poissons virtuellement perdue, dans les zones où les forêts ont déjà totalement disparu, est considérable. Par ailleurs, ces habitats essentiels se sont avérés rares et in-équitablement distribués le long des côtes : dans le cas des Diplodus spp. , moins de 10% des côtes rocheuses étudiées présentaient des habitats nourriceries. Enfin, ce travail a mis en évidence que la planification actuelle des mesures de gestion des zones côtières méditerranéennes ne prenait généralement pas en compte la distribution spatiale des habitats nourriceries, ni leur connectivité avec les autres habitats essentiels à chaque étape clef du cycle de vie des poissons. Un schéma conceptuel, visant à adopter une telle « approche paysage » de la gestion, est proposé : il vise à promouvoir une focalisation optimale des efforts de conservation et à garantir ainsi le renouvellement des peuplements de poissons côtiers
Udumyan, Narine. "Surexploitation des ressources halieutiques : habitat, récifs artificiels et apprentissage". Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM1082/document.
Texto completo da fonteThis thesis focuses on two main problems posed in contemporary fisheries: habitat degradation and lack of information. They count among the most important causes of the overexploitation of marine resources. The first two chapters aim at examining the habitat degradation that is linked to destructive fishing activities. The Gordon-Schaefer model is extended to take account of the negative impact of fishing on the habitats. The consequences for fisheries management are analyzed and the importance of taking into account habitats in the development of fisheries management programs is highlighted. Then the extended model is used to evaluate the economic benefits of artificial reefs, a management tool to which frequently resort the managers of small-scale fisheries to mitigate the effects of habitat degradation. Finally, in the third chapter the role of information for sustainable fisheries is examined under open access. If in the first two chapters it is assumed that there is complete information, in the last study this assumption is relaxed - no information on the resource is known. The decision concerning the exploitation of marine resources is made individually by each fisherman that operates in the fishery. By developing an agent-based model, we show the impact of individual learning on the global dynamics of the system
Pioch, Sylvain. "Les "habitats artificiels" : éléments de stratégie pour une gestion intégrée des zones côtières ? : essai de méthodologie d'aménagement en récifs artificiels adaptés à la pêche artisanale côtière". Montpellier 3, 2008. https://tel.archives-ouvertes.fr/tel-01971993.
Texto completo da fonteThis thesis under CIFRE contract aims to offer a methodology to change shore underwater marine systems into artificial habitat for ecosystem and fisheries exploitation. The objective is to give additional tools and answers to professionals specialised in fisheries and ecosystems management. The methodology is geo-systemic, it aims to integrate these changes into the ecosystem and socio-economic systems of artisanal fisheries (strategy type ICAM). The studies conducted on site in Japan taught us how to handle the integration of the underwater world through the relationship between species and their living space. This approach leads us to change the concept of "artificial reef" to the concept of "artificial habitat" as living spaces adapted for species living in a shore environment. The comparison of techniques from Japan, Portugal and France (the priority for these countries is to improve their marine parks with artificial habitat in order to help fishery related professions) helped us to identify a lack methodology in France. It is this global methodology that we want to define. The essence of this methodology is based on the relationship between society and nature at two levels : biophysical and socio-economical. It's organised by typology of artificial living space. Its application on one case study allows us to understand its limits and the necessity to define a common way of using such spaces. AH are participative transactional tools during concerted phases. We demonstrate that the wish to improve underwater living spaces enables the limitation and familiarization of shore territories which was until now unknown. The preservation of the shore ecosystems made possible by this methodology could assist in a balanced development of territorial collectivities
Champagnat, Juliette. "Modéliser l’impact des pressions anthropiques au niveau des habitats halieutiques sur la dynamique des populations de poissons marins exploités". Electronic Thesis or Diss., Rennes, Agrocampus Ouest, 2023. http://www.theses.fr/2023NSARH118.
Texto completo da fonteSpawning and juvenile habitats are Critical Essential Fish Habitats (CEFH) that support key phases of the life cycle, when fish aggregate on restricted areas. These CEFH face numerous anthropogenic pressures that impact fish locally. Yet, these impacts are poorly quantified at population scale. This PhD aims to fill this knowledge gap using ageand stage-structured modelling approaches, with explicit representation of the critical life stages on CEFH. A first approach aims to assess the impact of Seine estuary restoration for the common sole in the Eastern English Channel. It uses a hierarchical Bayesian modelling framework integrating a great amount of data and expertise to perform simulations of juvenile habitat restoration. The second one develops a generic mechanistic model to represent marine fish population with contrastedfish population with contrasted life histories. It integrates a comprehensive steepness-based parameterization of the stock-recruitment relationship that directly depends upon juvenile habitat quality and surface area. This model is used to explore population response to juvenile habitat degradation/restoration and its sensitivity to interspecific variability in demographic rates. Then the approach is applied to assess the potential impact of restoring estuarine nursery grounds for four species of main fisheries interest in the Eastern English Channel. Finally, the model is extended to integrate anthropogenic pressures affecting spawning grounds. The main hypothesis and limits of the approaches are discussed; this outlined the large venues of the generic model, for both further scientific investigation and help for management
Jézéquel, Céline. "Les communautés de poissons du bassin de l'Amazone : habitats aquatiques, gradients de diversité, facteurs et processus associés et options de conservation". Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30182.
Texto completo da fonteThe aquatic biodiversity of the Amazon basin, the largest and most species rich river basin on Earth, is still relatively poorly documented despite all the attention received from the international scientific community. Knowledge about the spatial distribution of species, and in particular of freshwater fishes, is very fragmented and dispersed between countries and institutions. The distribution of river forms has been also poorly explored at the scale of the entire basin, its continental dimension limiting the acquisition of field data. Improving the knowledge on the distribution of biodiversity and aquatic habitats in the basin is however a crucial step to better understand the factors and processes behind species diversification, identify priority areas for conservation (biodiversity hotspots) and assess the species vulnerability to global changes. This thesis work aims to reduce these significant knowledge gaps
Tamazouzt, Lakhdar. "L'alimentation artificielle de la perche perca fluviatilis en milieux confinés (eau recyclée, cage flottante) : Incidence sur la survie, la croissance et la composition corporelle". Nancy 1, 1995. http://docnum.univ-lorraine.fr/public/SCD_T_1995_0399_TAMAZOUZT.pdf.
Texto completo da fonteBergé, Julien. "Apport de la télémétrie acoustique pour la compréhension de l'utilisation dynamique des habitats par les poissons dans un grand fleuve aménagé, le Rhône". Phd thesis, Université Claude Bernard - Lyon I, 2012. http://tel.archives-ouvertes.fr/tel-00876252.
Texto completo da fonteBergé, Julien. "Apport de la télémétrie acoustique pour la compréhension de l’utilisation dynamique des habitats par les poissons dans un grand fleuve aménagé, le Rhône". Thesis, Lyon 1, 2012. http://www.theses.fr/2012LYO10092/document.
Texto completo da fonteIn this thesis, we studied the behavioral responses of fish to contrasting variations of theenvironment (flow, temperature and photoperiod) in order to understand (1) how fish react tothese changes and (2) if they have developed behavioral strategies in response to thesevariations.The behavioral data set used in this thesis comes from a continuous telemetry monitoringrealized during 89 days and recording positions of 61 fish of which 23 of barbel, 19 chub and 11catfish. The study site is an area of 2 km of the Rhone River subject to hydropeaking and locatedfront of the Bugey nuclear power plant that generates water heated on the right bank. The studysite is the subject of a 2D hydrodynamic modeling to know, at any point of the site and for allflow values, the local abiotic conditions.In order to know the quality of positions acquired during telemetric monitoring and how theperformance of the telemetry system is likely to vary during the monitoring of fish movements,the accuracy of this system has been previously studied in this thesis. To the best of possiblecombinations of intrinsic variables, the probability of detection varies from 0 to 80%, and theaverage error is 3-5 m in the channel and <10 m in banks. The geometrical configuration of thehydrophones located around the acoustic transmitter adjusts the probability of detection, whilethe setting of processing acoustic signals parameters adjusts the positioning error.The position data coupled with the hydrodynamic model were used to determine the habitatpreferences of fish, their spatial distribution and their movement, in response to changes in theenvironment (phases of photoperiod, water temperature and flow value). Habitat preferences ofthe three species are referred to depths <1.4 m, velocities <0.4 m.s-1 and coarse substrate (ratherrock and stone). The main difference is observed with the water temperature: cyprinids prefertemperatures <22 ° C, while catfish prefer temperatures> 23 ° C. These habitat preferences varymainly with the flow since the three species prefer during high flow (> 630 m3.s-1) habitats thatare hydraulically less stringent (lower speeds and depths and a coarser substrate). Photoperiodprimarily affects the movement of fish (barbel are crepuscular, the chub are diurnal and catfishare nocturnal) while the flow and temperature affect the spatial distribution of species. Cyprinidsuse very little the heated zone (<10% of the time) while catfish spend ~ 55% of their time in thisarea. During hours of high flow, the fish mostly use the banks and rarely exploit the channel.Finally, environmental variables acting in combination on fish behavior, such as cyprinids thatbenefit low flows during their phases of activity to exploit temporary habitats became available.Bugey fish have therefore implemented behavioral strategies based primarily on extensive useof shoreline areas that allow them to conduct most of their vital functions. The different speciesshow high fidelity to a few key habitats they use frequently throughout the day, but they canleave during certain combinations of environmental variations
Madéore-Le, Pichon Céline. "Une approche "Paysage aquatique" pour une meilleure connaissance du fonctionnement des écosystèmes fluviaux et l'amélioration de la conservation des peuplements de poissons". Paris 6, 2006. http://www.theses.fr/2006PA066538.
Texto completo da fontePaillon, Christelle. "Etude de la connectivité entre les communautés de poissons de différents habitats du lagon de Nouvelle-Calédonie par microchimie des otolithes et de l'environnement". Thesis, Nouvelle Calédonie, 2014. http://www.theses.fr/2014NCAL0058/document.
Texto completo da fonteEcological connectivity is defined by organism movements between habitats.Among the tools used to measure connectivity, otolith microchemistry is the only one able toreconstruct the fish movement throughout their entire lifetime, and thus include ontogeneticmigrations. However, it is seldom used in oligotrophic environments that typically show poorchemical contrasts such as coral reefs. In this context, this study focused on otolith microchemistryof coral reef and mangrove fishes of New Caledonia. This work comprises two parts. First, amethodological part to assess the potential of otolith microchemistry in New Caledonia, with onechapter on the determination of multi-elemental signatures of habitats from the Main Island and onechapter on the relationships between environmental and otoliths microchemistries. Second, thepreviously developed methodology was applied to ecological questions, with a chapter on theimportance of mangrove on the life cycle and the spatial distribution of a Lutjanidae, Lutjanusfulviflamma, and a chapter on the lifetime movement patterns of this species. Results revealed ahigh potential of otolith microchemistry in New Caledonia with a high power of discriminationbetween mangroves and coral reefs. Relationships between environmental and otolithmicrochemistries were complex and species-specific. However, strong chemical contrasts in theenvironment were traduced in the otoliths. Results showed a strong connection between differenthabitats for L. fulviflamma, in particular between mangroves and reefs with a crucial importance ofmangroves as nursery grounds. Three different patterns of lifetime movements among habitats wereidentified. This diversity illustrates a high variability of ecological connectivity patterns amongindividuals, with a possible return to the juvenile habitat during the adult stage
Dembski, Samuel. "Stratégies d'occupation spatiale en milieu lacustre : réponses de l'ichtyofaune dans un réservoir échauffé, non stratifié". Phd thesis, Université de Metz, 2005. http://tel.archives-ouvertes.fr/tel-00145435.
Texto completo da fonteLechêne, Alain. "Trajectoire de restauration des marais intertidaux : réponse du necton à la dépoldérisation dans l’estuaire de la Gironde". Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0883/document.
Texto completo da fonteEuropean intertidal marshes have greatly declined during the past centuries because of land claim andhave recently been threatened by the effects of climate change. In recent years, an increasing number of tidal resto-ration projects have been implemented, following a global trend termed de-embankment. This thesis describes therestoration trajectory of tidally restored marshes from the response of nekton (i.e., fish and decapod crustaceans)based on two storm-breached study sites in the Gironde estuary : the Mortagne marsh and the Nouvelle island.Nekton assemblage composition of tidally restored marshes was described through a whole-estuary approach en-compassing natural, restored and dyked habitats. Nekton assemblages of tidally restored marshes showed highcompositional similarity with natural intertidal habitats and greatly departed from dyked marshes. Dyked marsheswere characterized by high occurrence of freshwater exotic taxa. Tidally restored marshes seemed particularly at-tractive for the thin-lipped grey mullet, Liza ramada. The functional traits’ distribution within fish communities revealeda change in functional structure in the course of restoration using the naturalness state of habitats as a proxy forrestoration time. Most notably, functional specialization, dispersion and richness increased with restoration time.No clear pattern of change was observed in community assembly over time ; trends chiefly varied with respect totraits. Temporal trends in one of the restored sites revealed three phases in the first four years of tide restoration.The abundance of several species and the community functional structure changed more steeply in the midst ofthe second phase, less than two years following tide restoration. Community turnover was probably delayed dueto incomplete drainage of the site in the early stages of restoration. The results of this thesis lead to a better un-derstanding of the restoration trajectory of tidal marshes without human intervention and highlight the strengths andweaknesses of some theoretical models used in restoration ecology
Le, luherne Emilie. "Impacts des marées vertes sur les habitats essentiels au renouvellement des ressources halieutiques des secteurs estuariens et côtiers". Thesis, Rennes, Agrocampus Ouest, 2016. http://www.theses.fr/2016NSARH098/document.
Texto completo da fonteCoastal and estuarine systems are highly productive areas that provide unique biological and ecological services and shelter essential habitats to numerous fisheries resources. Among the perturbations experienced by these ecosystems, proliferations of opportunistic macroalgae, commonly known as ‘green tides’, are one of the most obvious signs of eutrophication in coastal and estuarine areas, worldwide, and in Northwestern France in particular. The processes underlying macroalgal proliferations are almost identified whereas their ecological consequences - especially for ichthyofauna - remain poorly understood and understudied. The objective of this thesis is to characterise the effects of green tides on the role of coastal and estuarine habitats for ichthyofauna, on both the community and the individual scales.First, we investigated the consequences of green tides on ichthyofauna on the community scale. Then, we examined the processes which affect the ichthyofauna during green tides, on the individual scale. Marine juvenile fish responses were investigated based on habitat selection and comparison of individual performances between a control and an impacted site. Based on these two complementary approaches, we evidence ecological significant negative effects of green tides on the quality of essential fish habitats. The effects of green tides on ichthyofauna are modulated by the intensity and nature of macroalgal blooms, and are related to the fish habitat use and ecology. A decreasing gradient of sensibility to green tides is emphasised, from benthic to demersal and pelagi
Daverat, Françoise. "Tactiques d'utilisation des habitats et dynamique de population des anguilles de la zone aval du bassin versant Gironde Garonne Dordogne : apport de l'étude des otolithes". Bordeaux 1, 2005. http://www.theses.fr/2005BOR13056.
Texto completo da fonteLelièvre, Stéphanie. "Identification et caractérisation des frayères hivernales en Manche Orientale et la partie sud de la mer du Nord : Identification des oeufs de poissons, cartographie et modélisation des habitats de ponte". Nantes, 2010. http://www.theses.fr/2010NANT2110.
Texto completo da fonteA better knowledge and monitoring of principal commercial fish spawning grounds have become necessary in the North Sea. The efficiency of CUFES was proved by sampling pelagic fish eggs in winter in Eastern Channel and Southern North Sea. Fish egg taxonomic identification based on visual criteria cannot always be carried out effectively. In particular, cod (Gadus morhua), and whiting (Merlangius merlangus) or flounder (Platichthys flesus) and dab (Limanda limanda) have the same range of egg diameter and similar morphologies. Alternative identification methods using molecular techniques were developed to improve the accuracy of egg taxonomic identification. First, PCR-RFLP method, then, in order to accelerate egg identification, the use of a new laboratory imaging system, the ZooScan, able to produce high resolution images of zooplankton samples, was adapted to fish eggs and allower their automated identification using supervised learning algorithms. The location of winter spawning grounds of fishes in the Southern North Sea and the Eastern Channel was illustrated using yearly maps and analysed over the available period to define recurrent, occasional and unfavorable spawning areas. Generally, fish eggs were found over the study area, except for the North Western of the North Sea, near Scottish coasts. Important spawning areas were clearly localised along the Belgian, Dutch and Danish coasts. Habitat modelling of these fish spawning areas was carried out using both GLM (Generalised Linear Model) and QR (Regression Quantile) and associated egg abundance to physical conditions such as temperature, salinity, bedstress, chlorophyll a concentration and bottom sediment types to characterize spawning habitat conditions and predict their extent and location. The results of this approach improve the understanding of spawning grounds distribution and were discussed in the context of the protection and conservation of critical spawning grounds
Chaine, Mimosa. "Étude du micro et du meiobenthos algal associés au Dinoflagellé Gambierdiscus toxicus Adachi et Fukuyo, agent causal princeps de la ciguatera, par la méthode des substrats neufs artificiels (atoll de Mururoa, Polynésie française)s". Montpellier 2, 1987. http://www.theses.fr/1987MON20268.
Texto completo da fontePastor, Jérémy. "Rôle des enrochements côtiers artificiels dans la connectivité des populations, cas du sar commun (Diplodus sargus, Linné, 1758) en Méditerranée nord-occidentale". Phd thesis, Université de Perpignan, 2008. http://tel.archives-ouvertes.fr/tel-00344703.
Texto completo da fonteThiriet, Pierre. "Comparaison de la structure des peuplements de poissons et des processus écologiques sous- jacents, entre les forêts de Cystoseires et des habitats structurellement moins complexes, dans l'Infralittoral rocheux de Méditerranée nord-occidentale". Thesis, Nice, 2014. http://www.theses.fr/2014NICE4061/document.
Texto completo da fonteIn Mediterranean rocky subtidal, large brown algae belonging to the genus Cystoseira form structurally complex habitats, called Cystoseira forest. Due to anthropogenic stressors, Cystoseira forests disappeared from numerous localities in the Mediterranean Sea and are deteriorating in other localities. Cystoseira forests are usually replaced by structurally less complex habitats, such as shrublands, turfs and barren. This PhD aimed to assess putative consequences for fish of Cystoseira forest degradation, and to identify the underlying ecological processes. Multiple complementary approaches were used: macroalgae and fish field surveys, tank-based predation and habitat-choice experiments, stable isotopes and stomach contents analyses. Densities of prey and predatory fish were higher in Cystoseira forests compared to structurally less complex habitats. This may be due to the shelter role of Cystoseira spp. that induces (1) reduced mortality of prey and predatory fish in forests, due to high shelter and food availability, respectively, and (2) net immigration of fish into forests due to their preference for this structurally complex habitat. Moreover, Cystoseira spp. may be an important source of organic matter to the ecosystem. This possible trophic role deserves complementary studies. This work suggests that Cystoseira forest degradation are harmful to fish and from this perspective stresses the need to better manage human activities impacting Cystoseira spp
David, Romain. "De la conception d'un système d'observation à large échelle au déploiement et à l'exploitation de son système d'information : application à l'observation des habitats coralligènes et à la colonisation de récifs artificiels (ARMS)". Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0215/document.
Texto completo da fonteIn the marine domain, observation protocols developed in many settings produce a large volume of heterogeneous data that are difficult to aggregate and use. This work proposes to develop i) methods, protocols and recommendations to build and / or support the establishment of multi-user monitoring networks, ii) innovative uses of data.Two case studies were chosen: coralligenous habitats at the Mediterranean scale and the colonisation of artificial reefs in different regional seas.Large-scale experimentation is based on the simplest possible measurement methods, described very explicitly in standardised terms, on intercalibrated operators and a method of data processing. A mechanism for coupling data from different origins based on the requalification of heterogeneous descriptive factors and a method for analysis and data mining based on graph theory is also proposed
Laugier, Flora. "Histoires de vie et connectivité entre les habitats écologiques essentiels de poissons des mers côtières tempérées : le cas des lançons (Ammodytidae) et du bar européen (Dicentarchus labrax, Linnaeus, 1758) dans le Golfe normand breton : une approche par les marqueurs de environnementaux". Paris, Muséum national d'histoire naturelle, 2015. http://www.theses.fr/2015MNHN0025.
Texto completo da fonteThe objectives of our thesis were to precise the use strategies of essential ecological habitats by coastal fishes in the west french Channel (Norman-Breton gulf and Lannion bay) using life traits for two taxa with contrasted biological cycles
Mablouké, Cécile. "Étude des ratios isotopiques du carbone et de l'azote de la matière organique particulaire et des muscles de poissons d'intérêt commercial d'écosystèmes côtiers tropicaux du sud-ouest de l'océan Indien : contribution à l'étude de leur fonctionnement". Thesis, La Réunion, 2013. http://www.theses.fr/2013LARE0017/document.
Texto completo da fonteThe aim of this thesis was to study the feeding habits of coastal fish species of commercial interest andto use stable isotopes of carbon (δ13C) and nitrogen (δ15N) to investigate the trophic niches of fish and their use of coastal habitats in the south-west Indian Ocean. In the Bay of La Possession, the species among the most abundant around the artificial reefs immersed in 2003 (Luljanus kasmira, Priacanthus hamrur and Selar crumenophthalmus) feed essentially on pelagic prey and partition their trophic niche to limit interspecific competition. There was also a positive correlation between fish size and muscle δ15N values due to fish larvae contributing more to the diet of fish with age. The stable isotopie composition of the particulate organic matter (POM) was measured at the microscale (< 10 km) in the Bay of La Possession, the mesoscale (10's of km) around Reunion Island and, for the fish muscles, at the macroscale 100’s of km) along the Mascarene plateau and the Mozambique channel. At microscale, POM δ15N values do not show any spatial variability; at mesoscale, POM is 15N-enriched in the south-west of Reunion Island; at macroscale, fish muscles are gradually 15N-enriched towards the north. At microscale, POM shows a 13C-enrichment on the shallowest station; at mesoscale, stations on the east coast of the island are 13C-enriched compared to the west; at macroscale, POMδ13C values are not significantly correlated with latitude. Thus, the stable isotopes of carbon do not seem to be appropriate for the study of fish coastal habitat use at the meso- and macroscale, and the stable isotopes of nitrogen represent a better indicator of fish habitat use at the macroscale
Martin, Jean. "Développement de la microchimie élémentaire et isotopique (87Sr : 86Sr) des otolithes de saumons Atlantique : évaluation du potentiel pour un appui à la gestion piscicole dans le bassin de l’Adour". Thesis, Pau, 2013. http://www.theses.fr/2013PAUU3004/document.
Texto completo da fonteThe Adour basin holds one of the largest populations of Atlantic salmon in southern Europe exploited by commercial and sport fisheries. Determining the relative contributions of individual rivers and hatcheries to the Adour basin populations becomes crucial to understand key sources that contribute the most to its persistence. We successfully used Sr:Ca, Ba:Ca and 87Sr:86Sr ratios as natural tags for determining the natal origins of adults from 12 tributaries. Success in discriminating between fish from different sites was greatest using Sr isotopes since the latter remained relatively constant across years at a given location. Geochemical signatures from core regions of the otolith were also used to identify fish from hatchery or naturally spawned sources. The predominance of adults spawned in the Ossau River among returning adults corresponded with long-term juvenile production trends in the Ossau River. Despite the limited upstream accessibility of the Pau River, our study demonstrated that Atlantic salmon recruits can successfully leave this river to join the adult population in the Adour basin. We observed relatively clear separation between hatchery and wild juveniles using both Sr:Cacore (wild > 2.5 and hatchery < 0.80) and 87Sr:86Srcore (wild < 0.710 and hatchery > 0.710). The return of hatchery reared fish as adult spawners represented 10% of the total sampled fish we analyzed. Almost all adults, previously identified as belonging to the Ouzom River, were hatchery produced. Adults originated from the Pau River were either wild or hatchery reared fish. We also conducted field controlled experiments that characterized the elemental uptake process in juvenile Atlantic salmon otoliths during freshwater residency. Physiological effects influenced Ba deposition. Ba:Ca otolith profiles from hatchery-reared and field collected fish were characterised by a peak at yolk absorption mark. Hatchery-reared fish stocked in a river also displayed a peak of Ba:Ca following transfer which was not related to the water chemistry. Our experiment revealed a 20-day lag time between initial Ba:Cawater changes and Ba:Caotolith saturation. Results suggested that such effects should be considered during any attempts to determine rivers of origin of Atlantic salmon based on otolith elemental composition or reconstruct the movement of individual fish among and within streams
Guéveneux-Julien, Cynthia. "Analyse comparative de modèles de la qualité des habitats basés sur la densité instantanée et cumulative de poissons". Thesis, 2021. http://hdl.handle.net/1866/25623.
Texto completo da fonteAquatic ecosystems contain approximately 25% of the global biodiversity and are among the most affected by human activity. This may be caused by the position of “receivers” rivers, lakes and oceans have in their watershed. Aquatic species, specially in freshwater, are thus at high risk of being affected by human activity. Assuring the survival of these species may include protecting and restoring their habitats. Habitat quality models (HQM) can be used to determine which habitats to protect and how to restore damaged habitats. HQM are relationships between habitat quality indices (HQI, e.g., density) and environmental conditions prevailing in those habitats. However, how well an HQM performs depends on the chosen HQI it is computed with. For this research, we compared HQM based on two HQI estimated for fish in a river : 1) instantaneous density, sampled by transect snorkeling survey and 2) cumulative density, sampled by fixed stereo-video recording. Analyses of twelve HQM show that, contrary to our hypothesis, HQM based on instantaneous density had higher explanatory capacities. However, environmental conditions selected by both types of HQM to explain a species’ distribution were different. This may in part be explained by inherent differences of the sampling methods (e.g., spatial scale). We conclude that instantaneous density as HQI produces HQM of higher explanatory capacities, yet both HQI may provide complementary information on the characteristics of habitats to protect and restore.
Gibeau, Pascale. "Variations temporelles des descripteurs des communautés de poissons dans la zone littorale de quatre lacs du Bouclier canadien". Thèse, 2006. http://hdl.handle.net/1866/17080.
Texto completo da fonteRoy, Mathieu. "Habitat variability and the individual variability of juvenile Atlantic salmon (Salmo salar)". Thèse, 2012. http://hdl.handle.net/1866/8984.
Texto completo da fonteSpatiotemporal flow variability contributes to create a dynamic habitat mosaic sustaining ecological diversity. One of the most important topics in ecohydraulic research is to identify the relevant scales of flow variability affecting organisms at different life stages. The general objective of the thesis is to examine the links between habitat variability and the behaviour of juvenile Atlantic salmon. More specifically, three themes are addressed: turbulence as a fish habitat variable, the spatial and temporal scales of habitat selection and individual variability in fish behaviour. Through detailed field measurements incorporating a variety of sampling techniques and statistical analyses our objectives were to: 1) Quantify the causal links between standard habitat variables and flow turbulence at multiple scales; 2) Test a new in situ portable flume to analyse the effect of turbulent flow properties on the prey capture probability and foraging behaviour of juvenile Atlantic salmon; 3) Analyse the spatial and temporal scale dependence of fish-habitat associations within a reach during the summer and autumn; 4) Examine individual variation of seasonal and daily activity patterns and habitat use and their interaction; 5) Investigate the individual variation in seasonal daily movement behaviour in relation to environmental fluctuations. The thesis provides a detailed characterization of turbulence in pools and riffles and showed that the capacity of ‘standard’ fish habitat variables to explain turbulent properties was relatively low, especially at smaller spatial scales, but varied greatly between the units. From a practical point of view, this level of complexity suggested that turbulence should be considered as a ‘distinct’ ecological variable within this range of spatial scales. In a second experiment, using an in situ portable flume and underwater videotaping of fish, we did not conclusively confirm or rule out the effect of turbulence on prey capture probability, but observed a preferential selection of locations where flow velocity was downward and turbulence intensity was lower. The selection of lower turbulence habitat was also observed in natural habitat conditions in an observational field study, in which 66 PIT-tagged fish were tracked for three months in a river reach using a high resolution network of antennas buried in the bed. Juvenile salmon habitat selection was dependant on the scale of observations. Fish were associated with moderate depth micro-scale habitats, but also with higher depth patch-scale habitats. Furthermore, the range of habitat used by individuals increased asymptotically with the temporal scale. The scale of one hour was considered as optimal to describe the range of habitats used in a day and three days optimal to describe the range of habitat used in a month. Individual tracking revealed high inter-individual variability in activity patterns, as some individuals were predominantly nocturnal whereas others frequently changed their daily activity pattern. Changes in activity patterns were linked to environmental fluctuations, but also to individual habitat use patterns, which might signify that lower quality habitats require fish to increase daytime activity when food intake and the risk of predation are both high. High inter-individual variability was also observed in the fish movement behaviour. It appeared that most fish exhibited low mobility on most days, but also showed occasional bouts of high mobility. Between-individual variability accounted for only 12-17% of the variability in the mobility data. These results challenge the assumption of a population composed of a sedentary and mobile fraction. Individual variation on a daily basis suggested that movement behaviour is a response to changing environmental conditions rather than an individual behavioural trait.