Dissertations / Theses on the topic 'Anthropogenic pressures'
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Radinger, Johannes. "Modelling fish dispersal in catchments affected by multiple anthropogenic pressures." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2014. http://dx.doi.org/10.18452/17067.
Full textThe colonisation of rivers by fishes is directly linked to abiotic habitat conditions but often impaired by dispersal abilities of fishes and movement constraints such as barriers. The first part of this thesis provides the first comprehensive quantitative analysis of freshwater fish movement while considering fish populations consisting of differently mobile specimens. 160 empirical datasets from 71 studies on the movement of 62 riverine fish species were analysed based on refitted leptokurtic probability-density functions (dispersal kernels). A share of one third and two thirds emerged as a general pattern of the mobile and stationary component of a fish population, respectively. Moreover, four variables were identified primarily determining dispersal distances: fish length, aspect ratio of the caudal fin, river size and time. In the second part of the thesis, the novel fish dispersal model FIDIMO is introduced. FIDIMO provides a GIS-tool for predicting and simulating spatio-temporal patterns of fish dispersal in dendritic river networks considering movement barriers. The fish dispersal model FIDIMO links conceptual considerations on dispersal modelling with empirically observed leptokurtic fish movement patterns and the strengths of geographically explicit modelling in Free and Open Source GIS. In the third part of the thesis, FIDIMO was applied for modelling dispersal of 17 fish species to disentangle the effects of (i) habitat suitability, (ii) dispersal constraints and (iii) network fragmentation on the distribution of river fishes. The results show significant positive effects of both, local-scale habitat quality and species-specific dispersal ability on the distribution of river fishes, whereas no significant effect of barriers influencing the presence of a species could be found. Over longer time periods the importance of dispersal decreased in favour of habitat suitability becoming relatively more relevant in determining species'' presence.
Besson, Marc. "Importance of metamorphosis in coral-reef fish larval recruitment facing anthropogenic pressures." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEP024/document.
Full textThe persistence and sustainability of coral-reef fish populations depends on the continued larval recruitment, i.e. successful settlement by pelagic larvae into adult reef habitats and post-settlement survival through metamorphosis to a juvenile stage. There is growing evidence that changes to water conditions due to global change and waterborne pollution can impair coral-reef fish sensory abilities to locate settlement habitats that maximize growth while minimizing mortality risk. However, the inner mechanisms of such impairments remain unknown. In this thesis, I have examined the recruitment phase of the convict surgeonfish Acanthurus triostegus, and determined that the ecological, morphological, physiological and behavioral changes occurring at recruitment correspond to a metamorphosis mediated by thyroid hormones (TH). Then, I investigated whether this metamorphosis is prone to endocrine disruption under anthropogenic disturbances such as elevated sea water temperature and agricultural pesticide pollution. I demonstrated that such pressures can reduce TH levels at a critical developmental stage in coral-reef fishes, impairing their metamorphic processes such as intestine remodeling, sensory organ maturation, and sensory abilities acquisition, further increasing their mortality rates. Overall, this thesis is a holistic analysis that addresses molecular, histological, anatomical, and behavioral assays of multiple stressors affecting coral-reef fish recruitment. It indicates the importance of a proper endocrine function during coral-reef fish recruitment, highlighting the need for a better understanding of these processes for coral-reef conservation
Ma, Jia Ji Wei. "A geospatial methodology for assessing wetland vulnerability under anthropogenic pressures at a watershed scale." Diss., UMK access, 2006.
Find full text"A dissertation in geoscience and software architecture." Advisor: Wei Ji. Typescript. Vita. Title from "catalog record" of the print edition Description based on contents viewed Nov. 13, 2007. Includes bibliographical references (leaves 248-261). Online version of the print edition.
Chiziane, Hércio Issac Patrício. "Analysis of morphometric attributes of benthic nematodes as descriptors of the different ecological conditions." Master's thesis, ISA/UL, 2018. http://hdl.handle.net/10400.5/17979.
Full textFree-living nematodes have been and are continually considered excellent bioindicators by several authors. Their high structural and functional diversity makes them more diversified and numerically dominant in aquatic habitats, with a wide distribution ranging from untouched habitats to highly polluted habitats. This fact as called the attention of many researchers who in turn motivated and promoted their use in the evaluation of the quality of water bodies. Farther, studies showed that morphometry and biomass are two important aspects to consider in ecological studies of free-living nematodes. The current study focuses on the investigation of the morphometric attributes of the free-living nematodes of the Tagus estuary (Portugal) in order to relate them to the various environmental conditions of the sediment along the estuary. Therefore, the following null hypothesis was tested: There will be no differences in the nematode morphometric parameters (length, width, L / W ratio and biomass) in the different sections of the estuary. Conclusions led to the rejection of the null hypothesis as significant differences were observed along the sections of the estuary for most of the morphometric attributes measurements taking in consideration the six most abundant genera of nematodes in the Tagus estuary (Terschellingia, Sabatieria, Daptonema, Ptycholaimellus, Viscosia and Anoplostoma). Though salinity, depth, grain size variables and organic matter were the environmental variables that were found to be more correlated with the nematode morphometric attributes variance along the estuary, nematode size and shape at investigated sections most likely reflected differences in quality and quantity of organic material and sediment size of the estuary. Most of the variability in terms of nematode morphometry along the Tagus estuary were verified for the genera Terschellingia leading to the conclusion that this genera can provide better information about the different environmental conditions of the sediment along the Tagus estuary
Os nemátodes de vida livre foram e são continuamente considerados ótimos bioindicadores por vários autores. A elevada diversidade estrutural e funcional dos nemátodes de vida livre torna-os o grupo mais diversificado e numericamente dominante em habitats aquáticos, com uma ampla distribuição que varia de habitats intocados a habitats altamente poluídos. Este fato chamou a atenção de muitos investigadores que, por sua vez, motivaram e promoveram o seu uso na avaliação da qualidade das massas de água. Além disso, estudos mostraram que a morfometria e biomassa são dois aspectos importantes a serem considerados em estudos ecológicos de nemátodes de vida livre. O corrente estudo foca-se na investigação dos atributos morfométricos dos nemátodes de vida livre do estuário do Tejo de modo a relacioná-los com as várias condições ambientais do sedimento ao longo do estuário. Para este efeito foi testada a seguinte hipótese nula: Não haverá diferenças nos parâmetros de nemátodes (comprimento, largura, relação C/L e biomassa) em diferentes secções do estuário. As conclusões levaram à rejeição da hipótese nula. Diferenças significativas foram observadas ao longo das seções do estuário para a maioria das medições dos atributos morfométricos dos seis géneros mais abundantes de nemátodes no estuário do Tejo (Terschellingia, Sabatieria, Daptonema, Ptycholaimellus, Viscosia e Anoplostoma). Embora a salinidade, profundidade, tamanho do sedimento e matéria orgânica tenham sido as variáveis ambientais mais correlacionadas com a variância dos atributos morfométricos dos nemátodes ao longo do estuário, o tamanho e a morfologia de nemátodes nas seções investigadas refletiram diferenças na qualidade e quantidade de matéria orgânica e tamanho do sedimento do estuário. A maior parte da variabilidade em termos de morfometria dos nemátodos ao longo do estuário do Tejo foi verificada para o género Terschellingia, levando à conclusão de que este género pode fornecer uma melhor informação sobre as diferentes condições ambientais do sedimento ao longo do estuário do Tejo
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Holzwarth, Ingrid [Verfasser]. "Implications of direct anthropogenic pressures on dissolved oxygen dynamics in a well-mixed estuary / Ingrid Holzwarth." Kiel : Universitätsbibliothek Kiel, 2018. http://d-nb.info/116822912X/34.
Full textFreitas, Luís Guilherme Pereira Antunes. "Planeamento de restauro fluvial do Rio Alcoa." Master's thesis, ISA/UTL, 2012. http://hdl.handle.net/10400.5/5321.
Full textThe European Union established a framework for Community action in the field of water policy. Considering the need for the natural resources protection and conservation, the Water Framework Directive 2000/60/EC Directive was adopted, involving the efforts of all Member States in the task of achieving good status for all waters, in which the aim of achieving good ecological state for natural ecosystems can be included. Within this context, the main objectives of this study are: the characterisation and quantification of the degradation degree in the fluvial ecosystem of the Alcoa river drainage basin, and to that end it was used the Predictive Ecological State methodology; and planning restoration actions for the most degraded stretches of the river system which deteriorate under the effect of human actions. Based on the results obtained, a Map of River Corridor Conservation Status was developed for the Alcoa river catchment area with the intend of revealing the degree of degradation of the river streams, and a Map of River Restoration Planning was developed which summarizes the restoration actions to be implement in the drainage basin.
Eilers, Silke [Verfasser], Helmut [Akademischer Betreuer] Hillebrand, and Thomas [Akademischer Betreuer] Brey. "Analysis and assessment of cumulative effects of anthropogenic pressures on ecosystem components / Silke Eilers ; Helmut Hillebrand, Thomas Brey." Oldenburg : BIS der Universität Oldenburg, 2021. http://d-nb.info/123414896X/34.
Full textRhodes, Monika, and n/a. "The Ecology and Conservation of the White-Striped Freetail Bat (Tadarida australis) in Urban Environments." Griffith University. Australian School of Environmental Studies, 2006. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20070314.114451.
Full textMestre, Débora Jesuíno. "Planeamento de restauro de corredores fluviais na bacia do Rio Grande." Master's thesis, ISA, 2013. http://hdl.handle.net/10400.5/6470.
Full textAccording to the Water Framework Directive (WFD), which requires Member States to take measures in order to protect, enhance and restore the superficial water bodies, looking to attain a good water quality status, the work at hand aims at assessing the ecological status of the Rio Grande water bodies, by implementing the Predicted Ecological State methodology. This methodology allows the division of the fluvial ecosystem in sections with homogenous features, the identification of its degradation level through the measurement of local anthropogenic pressures and plan rehabilitation measures and actions so as to achieve the goal set by the WFD.
Rhodes, Monika. "The Ecology and Conservation of the White-Striped Freetail Bat (Tadarida australis) in Urban Environments." Thesis, Griffith University, 2006. http://hdl.handle.net/10072/367292.
Full textThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
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Radinger, Johannes [Verfasser], Werner [Akademischer Betreuer] Kloas, Christian [Akademischer Betreuer] Wolter, and Andreas [Akademischer Betreuer] Melcher. "Modelling fish dispersal in catchments affected by multiple anthropogenic pressures / Johannes Radinger. Gutachter: Werner Kloas ; Christian Wolter ; Andreas Melcher." Berlin : Lebenswissenschaftliche Fakultät, 2014. http://d-nb.info/1063014131/34.
Full textCruz, Barrón Magali de la. "Compartmentalization of class 1 integrons and IncP-1 plasmids in the Orne river (France), an aquatic ecosystem impacted by urban and industrial anthropogenic pressures." Thesis, Université de Lorraine, 2018. http://www.theses.fr/2018LORR0212/document.
Full textMobile genetic elements (MGEs) are genetic structures frequently associated to the dissemination of antibiotic resistance genes (ARGs). In this work, we used two of them as proxies, class 1 integrons and IncP-1 plasmids, to better understand (i) the possible fate of ARGs once released in a river ecosystem (Orne, France), as well as (ii) the effect of anthropogenic pressures on their persistence. From river water analyses, we could show that the two MGEs do not behave the same way. The entry of class 1 integrons in the river system appeared to be diffuse rather than punctual, while the abundance of IncP-1 plasmid is relatively stable along the river section studied (23 km) thus indicating a rather indigenous origin. Anthropic inputs such as wastewater treatment plant did not seem to affect the abundance of MGEs because a too high level of effluent dilution. Interestingly, MGE-bearing bacteria appeared to be enriched on suspended material, which is likely to serve as a vehicle to drive MGE-richer communities of bacteria toward the sediments. The analysis of two sediment cores clearly indicates that only the top layers displayed an elevated level of MGE-bearing bacteria. These abundances decrease in deeper layers where only localized zones display micro-reservoirs of elevated MGE abundances. For one sediment core at least, we could show that the relative abundance of MGE negatively correlates with pollutants such as lead or certain PAHs
Nyegaard, Marianne. "There be giants! The importance of taxonomic clarity of the large ocean sunfishes (genus Mola, Family Molidae) for assessing sunfish vulnerability to anthropogenic pressures." Thesis, Nyegaard, Marianne (2018) There be giants! The importance of taxonomic clarity of the large ocean sunfishes (genus Mola, Family Molidae) for assessing sunfish vulnerability to anthropogenic pressures. PhD thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/41666/.
Full textBlanfuné, Aurélie. "Le changement global en Méditerranée Nord Occidentale : forêt de Cystoseires, de Sargasses, encorbellement à Lithophyllum et bloom d'Ostreopsis." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4024/document.
Full textThroughout the world, coastal ecosystems are severely affected by the cumulative impact of increasing human pressure (e.g. destruction of habitats, pollution, non-indigenous species, overfishing, coastal aquaculture and global warming). Different foms of stress act over time and in unison, with a possible synergistic effect, on species, ecosystems and their ability to deliver ecosystem services. Along temperate rocky coasts worldwide, large canopy-forming kelps (Laminariales, Phaeophyceae, Ochrophyta) and fucoids (Fucales, Phaeophyceae, Ochrophyta) represent the dominant species in pristine environments. In the Mediterranean Sea, species of the genus Cystoseira C. Agardh and Sargassum C. Agardh are habitat-forming species dominating several assemblages from the littoral fringe down to the lower sublittoral zone (0 down to 70-80 m depth). The present diachronic study based on the first usable scientific observations (18th century) is the first in the Mediterranean to cover such a long stretch of coastline (~ 2970 km at 1/2 500 scale). The results obtained by the analysis of historical and current data on the distribution of Fucales along the French coast differ according to the species studied, both with regard to the conservation status of populations and the causes involved in their regression. The general loss of habitat-structuring species is worrying. We are witnessing a typical regime shift with a replacement of macroalgal forests by less structured algal assemblages dominated by Corallinales or by barren grounds dominated by encrusting species, filamentous algae and sea urchins
Daeden, Jonathan. "Analyse des pressions anthropiques sur l’environnement littoral européen et français." Thesis, La Rochelle, 2015. http://www.theses.fr/2015LAROS019/document.
Full textCoastal management and conservation require the synthesis of geographic data on the distribution and intensity of human activities and their combined impacts on marine and terrestrial coastal ecosystems. Currently, across the European or French coasts, few studies provide a global view of risks on terrestrial and marine habitats. How are human pressures on biodiversity distributed? How to define the littoral system and thus improve management of this territory? At the European level, using 24 human pressures from EUROSTAT across the NUTS classification, we cut the European coasts in strips of 10 km to a limit of 100 km and identified the distribution and relative intensity pressures on coastal environments. We have shown that the great majority of the pressures occurs directly on the coastline and in the first 30 kilometers, then decreases sharply to the limit of 100 km. This division of the European coasts has also allowed us to use factorial correspondence analyses coupled with a hierarchical cluster analysis to divide the coastal territories in 4 coherent groups with the same pressures and relative intensities across Europe. At the French level, we have also developed a spatial model weighted by expert opinions based on geolocation of 15 human pressures on 81 marine and terrestrial biophysical habitats present on the metropolitan French coasts. The information is synthesized in the form of impact score applied to a mesh composed of 26000 cells (25 km²). This method of cumulative anthropogenic impacts scoring in an additive model shows areas with higher risks on both the marine and land territory. Again, the most affected areas by the human disturbances are close to the coast. Conversely, the least affected areas are those with a strong bathymetry and those with a significant elevation. We finally developed a participatory website that includes integrated GIS that allows the collection and dissemination of analysis of these human pressures on France following our additive model and allows at more local scales to return our analysis from any type of user. In the end few areas are not affected by human activities (0.1%) and a rather large fraction present very high risk (4.8%). The nearer the coastline, the more the risks are high. These analyses and maps are tools that give better understanding of conservation issues for the implementation of a socio-ecosystems coastal management and that will target the priorities in the conservation of our territories at a continental, national or local scale
Mateo, Santos Maria. "Réponses adaptatives des anguilles tempérées à l’hétérogénéité environnementale : mécanismes évolutifs, menaces liées au changement global et conséquences pour la conservation." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0713/document.
Full textThe worldwide decline of temperate eels is due to a synergistic combination of several anthropogenic pressures. However, eels display very specific life-cycles and amazing adaptation capacities that impair our ability to assess the relative effects of each pressure. Temperate eels are three catadromous species with large spatially distribution area during their continental growth stage. Their panmixia and the passive larval drifts impair the possibility of local adaptation; however life history spatial patterns are correlated with environmental gradients at both river catchment and distribution area scales. ThisPhD aims (i) to explore whether these life history spatial patterns may result from two adaptive responses: genetic polymorphism and adaptive phenotypic plasticity, and (ii) to revisit the effect of different components of global change in consideration to these adaptive responses. In this context,GenEveel, an individual-based optimization model was developed. The model postulates that genetic dependent habitat selection and phenotypic plasticity are mechanisms to address environmental heterogeneity. With such assumptions, the model was able to mimic observed spatial patterns in length-at-silvering, sex ratio and distribution of ecotypes. Moreover, different types of anthropogenic pressures (glass eel fishery, silver eel fishery, obstacles to upstream migration, and mortality due to hydropower facilities) were integrated in the model. Then, the model was used to assess their impacts on the number of escapees and their attributes: sex ratio, repartition between genotypes, mean lengthat-silvering, and overall egg production. The results showed that the pressure that induces the highest direct mortality has not necessarily the greatest influence on the spawning biomass and does not necessarily exert the strongest selective pressure on the ecotypes. This demonstrates that phenotypic plasticity can be a source of resilience for the population and mitigates the effect of some but not all the pressures. It also suggests that management should not only focus on numbers and direct mortalitybut on the preservation of diversity within populations. Finally, a demo-genetic model is described summarizing our understanding of eel populations. Such model can be used in the future to explore the ecological conditions in which genetic polymorphism and phenotypic plasticity have been selected through generations and provide new insights for the conservation of endangered eel species
Launois, Lionel. "Impact des facteurs anthropiques sur les communautés piscicoles lentiques : vers l'élaboration d'un indice poisson." Thesis, Aix-Marseille 1, 2011. http://www.theses.fr/2011AIX10044/document.
Full textFish communities remain underused in the domain of lentic ecosystem bioindication, even though water managers need such tools in the current context of the Water Directive Framework. The objective of this thesis was to analyse the fish communities’ response to various anthropogenic pressures, in order to define the candidate biological variables in bioindication and to develop an index to evaluate the ecological status of French natural lakes and reservoirs. Several questions are raised.First of all, the means available to select fish-based metrics responding to catchment-scale anthropogenic pressures are analysed using a typological approach. This analysis consists in classifying lentic ecosystems using classifications, and then, within each homogenous group of ecosystems identified based on environmental criteria, performing linear regressions between candidate fish-based metrics and anthropogenic pressures. The results clearly show that fish communities could be used as good bioindicators for the lentic ecosystems, but they also underline the limits of typological approaches.To test how a bioindicator shared by natural lakes and reservoirs could be developed, an alternative site-specific method was subsequently developed. Statistical modeling was applied to control the natural environmental effects on lentic fish communities. This analysis shows that fish-based metrics responding to catchment-scale anthropogenic pressures differ in the two types of lentic ecosystems.The last part reports the development of an index, based on the reference condition approach, using a hindcasting statistical approach. This method, still infrequently used, enables one to sidestep the problem related to the selection of reference sites in France. Furthermore, this method allows modeling biological reference conditions, i.e. conditions without anthropogenic pressures. Fish communities’ characteristics are then compared for both undisturbed sites and sites that are more or less impacted by anthropogenic pressures. Both catchment-scale and local anthropogenic pressures were considered in this analysis. Following this protocol, a lake fish-based index resulting from the combination of metrics that respond jointly to global and local anthropogenic pressures was developed for natural lakes and reservoirs. Finally, the advances made as a result of this research and its perspectives are discussed with regards to the European context of aquatic ecosystem management
Duval, Bastien. "Ecodynamics of trace metals and metalloids in Pyrenean lakes in relation to climate change and anthropogenic pressure." Thesis, Pau, 2020. http://www.theses.fr/2020PAUU3046.
Full textThe management and conservation of Pyrenean high mountain lakes within the current context of climate change and increasing anthropogenic pressure require detailed knowledge of their biogeochemical functioning. In this doctoral thesis, five sampling campaigns were carried out (2017-2019) in more than 20 alpine lakes. The analysis of water samples allowed us to study the occurrence, the depth profiles, the geographical distribution and the seasonal trends of a large array of physico-chemical and biogeochemical parameters. Specifically, the cycle of carbon dioxide (CO2) and the fate of Potentially Harmful Trace Elements (PHTEs) were investigated. The mercury (Hg) was specially studied through the development of an analytical procedure for the measurement of trace concentrations in natural waters and through biogeochemical investigations on the distribution and the fate of Hg species in the water column, as well as in sediment archives.The new and robust procedure developed in this work to measure the total alkalinity (TA) and the dissolved inorganic carbon (DIC) allowed us to determine the other two parameters of the CO2 system, the pH and the fugacity of CO2 (fCO2). The bedrock characteristics of the watershed appear to be the most important parameters influencing the acid status of the studied lakes. Moreover, obtained fCO2 values indicate that lakes are sources of CO2 for the atmosphere.The measurement of various physico-chemical parameters allowed us to discriminate and classify the studied lakes according to their water geochemistry, highlighting the importance of the trophic status of the lakes, the geological background and the atmospheric inputs. The occurrence, sources and behaviour of the PHTEs were investigated with evidence of a contrast between geological and atmospheric inputs. Intensive monitoring revealed some PHTEs to be highly sensitive to environmental changes such as temperature and redox conditions.Monitoring natural concentrations of total Hg in aquatic systems remains a difficult challenge and there is a need for the development of low cost and easy handling analytical methods. The method for analysis of trace Hg concentrations developed and optimized in this work was successfully operational and exhibits a suitable limit of detection and an excellent reproducibility. Hg speciation results in the water column demonstrated the pristine state and the dynamic of the Pyrenean lakes. The homogeneity in the non-gaseous total Hg concentrations in the studied lakes confirmed the absence of local sources and the potential use of these ecosystems as sentinels of regional to global Hg contamination. While inorganic mercury (iHg) did not show seasonal variations, monomethylmercury(MMHg) was significantly higher in autumn 2018 and dissolved gaseous mercury (DGM) varied strongly within and among lakes. In-situ experiments confirmed the conditions that promote Hg methylation (stratified anoxic waters), demethylation and photoreduction (intense UV light).The historical Hg record in sediment archives highlighted temporal trends in Hg accumulation rates (HgARs) with a progressive increase since the 16th Century and the industrialization, mirroring the Hg production in Almadén mines (Southern Spain). Besides, Hg stable isotopes allow the identification of distinct anthropogenic sources as well as past climate variability.Overall, environmental changes in lake ecosystems, induced by either climatic conditions (temperature, light intensity) or anthropogenic pressure (atmospheric inputs, eutrophication, atmospheric CO2) are likely to produce significant impacts among CO2, specific PHTEs and Hg biogeochemical cycles in mountainous ecosystems
Galindo, Romero Marta. "Spatial Variations in the Acoustic Peak Pressure of Impulsive Low Frequency Anthropogenic Signals in Underwater Marine Environments." Thesis, Curtin University, 2017. http://hdl.handle.net/20.500.11937/59661.
Full textГусєва, Аліна Віталіївна. "A complex assessment of the ecological state of the city of Kherson by bioindication method." Thesis, Національний авіаційний університет, 2020. http://er.nau.edu.ua/handle/NAU/43589.
Full textObject of research: change in the composition of atmospheric air under the influence of anthropogenic activity Subject of research: the level of air pollution Aim оf research: to assess the ecological state of the city of Kherson, to estimate the anthropogenic load on the city using bioindication methods. Methods of research – information search, analysis and synthesis of information, comparative analysis, mapping, visual observations, method of phytoindication, method of lichen indication. The practical value of the work is to determine the anthropogenic impact on the city and the environment. Creation of a map of anthropogenic load on the city and maps of city pollution. The results of the thesis can be used in the course of research and in practice by both local residents and environmental experts. Information of the thesis can serve the development of the environmental awareness of city residents.
Гусєва, Аліна Віталіївна. "A complex assessment of the ecological state of the city of Kherson by bioindication method." Thesis, Національний авіаційний університет, 2020. https://er.nau.edu.ua/handle/NAU/49653.
Full textObject of research: change in the composition of atmospheric air under the influence of anthropogenic activity Subject of research: the level of air pollution Aim оf research: to assess the ecological state of the city of Kherson, to estimate the anthropogenic load on the city using bioindication methods. Methods of research – information search, analysis and synthesis of information, comparative analysis, mapping, visual observations, method of phytoindication, method of lichen indication. The practical value of the work is to determine the anthropogenic impact on the city and the environment. Creation of a map of anthropogenic load on the city and maps of city pollution. The results of the thesis can be used in the course of research and in practice by both local residents and environmental experts. Information of the thesis can serve the development of the environmental awareness of city residents.
Bouvais, Pierre. "Influence of increased sediment exposure on suspension-feeder assemblages in a temperate seagrass meadow." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2016. https://ro.ecu.edu.au/theses/1814.
Full textDos, Santos Abade Leandro. "Examining the spatial occurrence of carnivores across a gradient of anthropogenic pressure in southern Tanzania, with a focus on the Ruaha landscape and adjacent areas." Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:b990940d-c823-4be4-b7ec-abc76d83572e.
Full textLootvoet, Amélie. "Le rôle du comportement dans la vulnérabilité aux pressions anthropiques et à l'extinction chez les Primates." Thesis, Paris, AgroParisTech, 2014. http://www.theses.fr/2014AGPT0080.
Full textImproving species protection and better understanding the mechanisms leading to population decline and ultime extinction has become a major research area over the last decades. Nowadays, the causes of extinction are mostly anthropogenic, but some intrinsic factors, specific to each species, can interact with these anthropogenic pressures to determine the extinction risk. Many studies have highlighted the impact of life history traits and ecological characteristics on species vulnerability to extinction, but very few have investigated the role of behaviour. Because of the mechanisms they imply, several behaviours could constitute intrinsic factors of vulnerability among species, at the level of extinction risk, or concerning the main anthropogenic pressures threatening species. The aim of this thesis is to determine the impact of the social system and sexual selection on primate vulnerability i) to the main anthropogenic threats (i.e. hunting, logging and agriculture) and, particularly, the role of infanticide on their vulnerability to hunting, and ii) to the extinction risk as described by the IUCN conservation status. This point has lead us to examine also the impact of human footprint heterogeneity on extinction risk. All our studies are based on a comparative analysis approach. Our different works highlighted several impacts of behavioural variables at the two spatial scales and for the two levels of vulnerability, but with differences in the nature of the behavioural variables. We identified significant effects of the average group size and the socio-reproductive system in species vulnerability to logging, but not in species vulnerability to the other threats. Moreover, these effects have also been found at the level of the extinction risk, but in different ways. Thus, the mechanisms implicated in the vulnerability are different according to the type of vulnerability, and rely on several Allee effects
Singh, S. K. (Sujeet Kumar). "Conservation genetics of the Bengal tiger (Panthera tigris tigris) in India." Doctoral thesis, Oulun yliopisto, 2017. http://urn.fi/urn:isbn:9789526215662.
Full textTiivistelmä Tiikeri on nykyisin uhanalainen lajin elinympäristön supistumisen ja pilkkoutumisen vuoksi. Lajin tärkein esiintymisalue on Intian niemimaalla, joka on siten kriittisen tärkeä alue tiikerin suojelun kannalta. Intiantiikereitä esiintyy useilla pienillä suojelualueilla Intiassa. Kaksi tärkeää tiikerin esiintymisaluetta Intiassa ovat Terain kaaren (TAL) alue luoteis-Intiassa sekä Sundarbansin mangrovealue Bangladeshin rajalla. Näiden alueiden tiikereistä ei ole ollut olemassa geneettistä perustietoutta, jota tarvitaan, kun arvioidaan ihmisen toiminnan ja ilmastonmuutoksen aiheuttamia muutoksia tiikeripopulaatioiden geneettisessä koostumuksessa sekä kun määritellään lajin suojelun kannalta merkittäviä luonnonsuojeluyksikköjä. Tässä väitöskirjatutkimuksessa tutkittiin Terain kaaren ja Sundarbansin alueen tiikereiden geneettistä monimuotoisuutta ja rakennetta sekä tuman että mitokondrion geenimerkkien avulla. Tutkimuksessa selvitettiin kolmenkymmenyhdeksän tuman geenimerkin (mikrosatelliitin) soveltuvuutta intiantiikerin geneettisiin tutkimuksiin, ja näistä valittiin kolmetoista käytettäväksi läntisen Terain kaaren ja Sundarbansin alueiden tiikereiden geneettisiin tutkimuksiin. Terain kaaren alueelta tutkittiin seitsemänkymmenentäyksi intiantiikerinäytettä. Tulosten perusteella alueella on aikaisemmin havaitsematonta kryptistä populaatiorakennetta. Geenivirtaa eri alapopulaatioiden välillä oli kohtuullisen paljon, mutta se oli epäsymmetristä. Tiikereiden geneettinen monimuotoisuus oli melko suurta eikä geneettisillä menetelmillä havaittu eri alapopulaatioissa merkkejä populaation koon pullonkauloista. Jotta alapopulaatioiden välinen yhdistyneisyys säilyisi jatkossa, joidenkin kylien siirto toisaalle on välttämätöntä. Ihmisten luvaton levittäytyminen tiikerin elinalueita yhdistävillä käytävillä täytyisi saada hallintaan sekä kieltää hiekanotto ja kivenlouhinta. Sundarbansin alueelta ei-invasiivisesti kerätyt tiikerinäytteet tutkittiin sekä tuman että mitokondrion merkkigeenillä ja alueen tiikereiden geneettistä koostumusta verrattiin manner-Intian tiikeripopulaatioiden koostumukseen. Sundarbansin tiikereiden todettiin poikkeavan geneettisesti manneralueen tiikeripopulaatioista ja niiden geneettinen monimuotoisuus oli alhaisempaa kuin manneralueella. Koalesenssisimulaatiohin perustava demografinen analyysi viittasi Sundarbansin tiikereiden suhteellisen viimeaikaiseen (600—2000 vuotta sitten) erkanemiseen manneralueen tiikereistä. Sekä historialliset että geneettiset todisteet tukivat teoriaa, jonka mukaan Sundarbansin tiikereillä olisi ollut yhteyksiä mannermaan tiikereihin aivan viime aikoihin asti. Geneettinen isolaatio mannermaan tiikereistä ja adaptaatio mangrove-ekosysteemiin ovat yhdessä muovanneet Sundarbansin tiikereiden geneettistä arkkitehtuuria. Tämän vuoksi Sundarbansin tiikerit vaativat erityistä suojelua, jotta niiden geneettinen ainutlaatuisuus ja kyky sopeutua erityisolosuhteisiin säilyisivät myös tulevaisuudessa. Populaatiota täytyy hoitaa evolutiivisesti merkittävänä yksikkönä (evolutionary significant unit; ESU) adaptiivisen evolutiivisen suojelun (adaptive evolutionary conservation; AEC) kriteeristön mukaisesti. Tutkimuksessa kiinnitettiin huomiota myös ongelmiin, joita saattoi ilmetä aikaisemmin ehdotetuissa menetelmissä eri sukupuolten kautta kulkevan geenivirran määrän arvioimiseksi ja ehdotettiin vaihtoehtoista menetelmää tarkempien arvioiden saamiseksi
Becquet, Vanessa. "Evaluation des capacités adaptatives du bivalve Macoma balthica (L.) dans un contexte de changement global : analyse comparée des processus neutres et soumis à sélection." Phd thesis, Université de La Rochelle, 2011. http://tel.archives-ouvertes.fr/tel-00591636.
Full textGage, Karla Leigh. "EFFECTS OF ANTHROPOGENIC SELECTION PRESSURE ON THE EVOLUTION OF A COMMON AGRICULTURAL WEED: DOES ADAPTATION COME WITH A DETECTABLE COST? A STUDY OF GLYPHOSATE-RESISTANT (GR) AND -SUSCEPTIBLE (GS) BIOTYPES OF Conyza canadensis." OpenSIUC, 2013. https://opensiuc.lib.siu.edu/dissertations/677.
Full textSoofi, Mahmood [Verfasser], Matthias [Akademischer Betreuer] Waltert, Niko [Gutachter] Balkenhol, Michael [Gutachter] Mühlenberg, and Eckhard W. [Gutachter] Heymann. "Effects of anthropogenic pressure on large mammal species in the Hyrcanian forest, Iran : Effects of poaching, logging and livestock grazing on large mammals / Mahmood Soofi ; Gutachter: Niko Balkenhol, Michael Mühlenberg, Eckhard W. Heymann ; Betreuer: Matthias Waltert." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://d-nb.info/1151398942/34.
Full textMachado, Fernando Henrique. "Proposição de indicadores de segurança hídrica : seleção, validação e aplicação na bacia hidrográfica do rio Jundiaí-Mirim, Jundiaí - SP, Brasil /." Universidade Estadual Paulista (UNESP), 2018. http://hdl.handle.net/11449/153669.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
As bacias hidrográficas localizadas em áreas densamente ocupadas e industrializadas sofrem diferentes pressões antrópicas, situação que compromete a qualidade e quantidade da água. Esse cenário, peculiar nas bacias hidrográficas dos rios Piracicaba, Capivari e Jundiaí (BH-PCJ), reflete também na sub-bacia hidrográfica do rio Jundiaí-Mirim (BH-JM), responsável pelo fornecimento de 95% da água consumida por Jundiaí-SP. Todavia, a vazão produzida nesta bacia é insuficiente para atender as demandas do município, necessitando da reversão sazonal das águas do rio Atibaia. Diante desse quadro de estresse hídrico, este estudo visou propor e analisar um conjunto de indicadores de segurança hídrica visando a melhoria da capacidade de planejamento e gestão dos recursos hídricos da BH-JM. Assim, utilizou-se de uma abordagem metodológica pautada na seleção, validação, aplicação e estruturação de indicadores de segurança hídrica em um modelo de causa-efeito. Os indicadores foram submetidos à avaliação por meio de um painel multidisciplinar de especialistas utilizando-se o método Delphi. Os indicadores validados pelo painel foram discutidos e, posteriormente, sistematizados a fim do estabelecimento das diretrizes. Os indicadores selecionados foram: (i) oferta de água; (ii) reservatórios de água; (iii) rede de distribuição; (iv) perdas na distribuição de água potável; (v) transposição de água; (vi) qualidade físico-química e biológica da água; e (vii) políticas públicas. Os principais resultados foram: (i) a série histórica analisada apontou um crescimento populacional de 1,8% a.a., conquanto a produção de água tratada cresceu a taxas inferiores (1,2% a.a.), onde verificou-se a redução constante do consumo per capta de 248 L hab.-1 dia-1 para 203 L hab.-1 dia-1 em um período de 17 anos; (ii) as áreas ocupadas por lagos e reservatórios foram ampliadas em 703% em um período de 4 décadas, sendo a maior área representada pelo reservatório de abastecimento público, do qual estimou-se receber uma carga de sedimentos de 1,5 mil t ano-1 ; (iii) o crescimento geométrico da rede de distribuição aumentou a taxas de 3,1% a.a., refletindo no aumento linear do número de ligações ativas de água; (iv) as perdas médias do sistema de distribuição de água potável encontra-se na ordem de 34% ao longo de quase duas décadas, representando perdas de aproximadamente 17,6 milhões de m3 ano-1 ou R$ 38,3 milhões ano-1 ; (v) uso cada vez mais frequente das águas revertidas do rio Atibaia, medida que pode emergir inúmeros desdobramentos e conflitos futuros pelo uso da água na região; (vi) alterações adversas na qualidade físico-química da água da BH-JM em decorrência da transposição, como o aumento na concentração de íons metálicos, turbidez, cloreto, dentre outros; (vii) identificou-se um amplo aparato jurídico-ambiental relacionadas à BH-JM, porém com baixa eficácia jurídica em suas aplicações. Em face dos resultados, 49 diretrizes de gestão foram propostas. Desse modo, a abordagem metodológica empregada revelou-se adequada e replicável para outras bacias, uma vez que: a partir do método Delphi foi possível estabelecer critérios de seleção de indicadores considerando a problemática em análise; a discussão individual dos indicadores permitiu uma melhor compreensão das dinâmicas envolvidas em cada indicador; a estruturação dos indicadores em um modelo-causal permitiu a sistematização das informações e, consequentemente, contribuiu para o estabelecimento das diretrizes.
The river basins located in densely occupied and industrialized areas are subject to different anthropogenic pressures, a condition that compromises directly the quality and quantity of water resources. This situation is common in the Piracicaba, Capivari, and Jundiaí river basins (BH-PCJ), southwestern Brazil, as well as in the Jundiaí-Mirim river basin (BH-JM) (sub-basin of the Jundiaí river). The BH-JM is a strategic area due to supply 95% of the raw water consumed by Jundiaí-SP. However, the available water flow in this basin is not enough to meet the local demands. This fact led to the need for seasonal interbasin water transfer from the Atibaia river. In view of this water stress scenario, this study aimed to propose and analyze a set of water security indicators for improving the planning and management capacity of the BHJM water resources. Therefore, a methodological approach based in selection, validation, application and structuring of water safety indicators was used in a cause-effect model. The indicators were submitted to the assessment through a multidisciplinary panel of experts using the Delphi method. The valid indicators from the panel were well discussed and, posteriorly, systematized for purpose of establishment of guidelines. The selected indicators were: (i) water supply; (ii) water reservoir; (iii) drinking water distribution system; (iv) drinking water losses in the distribution system; (v) interbasin water transfer; (vi) physical-chemical and biological water quality; (vii) public policies. The main results were: (i) the historical series analyzed showed a population growth rate of 1.8% p.a., while the potable water production was 1.2% p.a., where there was a constant reduction of consumption of 248 L inhabitant-1 day-1 to 203 L inhabitant-1 day-1 in 17 years; (ii) the areas occupied by lakes and reservoirs in BH-JM were increased by 703% in 4 decades, the largest area represented by the public supply reservoir, from which it was estimated that a sediment load of 1,5 thousand tons-1 ; (iii) the geometric growth of the distribution network was of 3.1% p.a., reflecting the linear increase in the number of hydrometric water connections; (iv) the average of drinking water losses in the distribution systems was around 34% over almost two decades, representing losses of about 17.6 million m3 year-1 or R$ 38.3 million year- 1 ; (v) increasingly frequent use of the interbasin water transfer from Atibaia river, a measure that may result in many unfolding and future conflicts over the use of water in the region; (vi) adverse changes in the physical-chemical quality of BH-JM water due to interbasin water transfer, such as the increase in the concentration of metallic ions, turbidity, chloride, among others; (vii) an ample environmental legislative framework related to BH-JM was identified, but with low legal effectiveness in their applications. In view of the results, 49 management guidelines were proposed. Therefore, the methodological approach used demonstrated to be adequate and replicable for other river basins, once that: the Delphi method developed allowed to set up criteria of indicators selection considering the research questions analyzed; the indicators discussion allowed a better understanding of the dynamics involved in each indicator; the indicators structuring in a causal model allowed the information systematization and, thus, it is contributed to the establishment the management guidelines.
Capes-DS
Бояр, Андрій Олексійович, and Andrii O. Boiar. "Територіальна організація еколого-економічного комплексу Волинської області." Diss., Волинський державний університет імені Лесі Українки, 2003. http://evnuir.vnu.edu.ua/handle/123456789/13674.
Full textA deep geographical research of the problems of optimization of society ecological-economic parameters within the terms of transition to the sustainable development is carried out in the dissertation. The particular scientific analysis of the factors of the Volyn Region ecological-economic complex formation is given as well as the territorial and constructive peculiarities of the economy influence over the environment are considered. The levers of the economic regulation of the ecological-economic processes adequate for the Region at present are generalized. Both the economic losses from the environment pollution by the economy subjects of the Volyn Region and the indexes of the ecological tension of the administrative districts geoecosystems are calculated. Four ecological-economic zones within the territory of the Region are marked out. The most actual perspective directions of the ecological-economic conversion of the economy are proposed.
Jeanneau, Laurent. "Approche moléculaire quantitative appliquée à l'étude du transfert de micropolluants organiques à la confluence entre la Fensch et la Moselle (France)." Phd thesis, Institut National Polytechnique de Lorraine - INPL, 2007. http://tel.archives-ouvertes.fr/tel-00221452.
Full textLaço, José Maria Serpa. "Rivers as routes for the spread of antibiotic resistance: role of anthropogenic pressures and risks to Human health." Master's thesis, 2020. http://hdl.handle.net/10316/92611.
Full textA resistência a antibióticos é um problema crescente a nível mundial associado ao uso abusivo de antibióticos tanto em humanos como animais. Enterobacteriaceae resistentes a cefalosporinas de 3ª geração geram grande preocupação, dado que são fármacos de primeira linha utilizados para tratar infeções causadas por estes agentes infeciosos. A resistência a este tipo de antibióticos é mediada por beta-lactamases de espectro alargado (ESBLs), sendo as CTX-M as mais prevalentes a nível mundial. O rio Lis é um rio com elevados níveis de poluição localizado na região centro de Portugal, sujeito a diversas pressões antropogénicas incluindo descargas ilegais de resíduos provenientes de suiniculturas. Este estudo tem como objetivos: 1) determinar a prevalência de Enterobacteriaceae resistentes a cefotaxima ao longo do rio Lis em dois anos; 2) determinar a afiliação filogenética, clonalidade e perfis de suscetibilidade a antibióticos de bactérias portadoras do gene blaCTX-M isoladas deste rio; e 3) caracterizar a diversidade de genes blaCTX-M, o seu contexto genómico e associação a elementos genéticos móveis. O rio Lis apresentou qualidade da água muito baixa nos 15 locais amostrados, tanto em 2018 como em 2019. Dados recolhidos em 2018 revelaram a presença de bactérias resistentes a cefotaxima em todos os locais, geralmente mais abundantes em locais com menor qualidade da água. Em 2019 foi observada a mesma tendência, mas não foi detetada qualquer bactéria resistente a cefotaxima em três dos locais amostrados. Dos 147 isolados resistentes à cefotaxima distribuídos por 9 géneros, em 68 (46%), pertencentes a 4 géneros, foi detetado o gene blaCTX-M. A tipagem molecular mostrou a presença de isolados provavelmente clonais em diferentes locais e nos dois anos, sugerindo persistência das estirpes no rio e provavelmente fontes de poluição contínuas. Os isolados clonais recolhidos no mesmo local e no mesmo ano foram excluídos da restante análise. Os restantes 54 isolados pertenciam aos géneros Escherichia (n = 32), Klebsiella (n = 18), Enterobacter (n = 3) e Citrobacter (n = 1). Destes isolados, 79,6% mostraram perfis de multirresistência, com 2 isolados a revelarem baixa suscetibilidade ao imipenemo, um antibiótico utilizado em último recurso. Sete variantes diferentes de blaCTX-M foram encontradas, nomeadamente blaCTX-M-1, blaCTX-M-3, blaCTX-M-15, blaCTX-M-32, blaCTX-M-55, blaCTX-M-14, blaCTX-M-27 e blaCTX-M-65, sendo a blaCTX-M-15 a mais prevalente (52,5% dos isolados), tal como descrito mundialmente. A variante blaCTX-M-65 foi detetada pela primeira vez em Portugal. A ISEcp1 foi detetada na região a montante do gene para todas as variantes, e IS903 ou orf477 estavam presentes na região a jusante do gene. Os resultados deste estudo reforçam os graves problemas de poluição no rio Lis. Em locais com mais baixa qualidade da água foram registados os níveis mais elevados de resistência e prevalência do gene blaCTX-M, sugerindo este gene como um marcador de poluição. O número elevado de variantes de blaCTX-M detetadas em Enterobacteriaceae, em contextos frequentemente descritos em isolados clínicos, sugere que a água do rio Lis representa um risco considerável para a saúde humana. Este risco deve ser avaliado em detalhe dado que a água deste rio é utilizada frequentemente para irrigação, pesca e atividades de lazer.
Antibiotic resistance is a growing worldwide problem derived from overuse of antibiotics in both humans and animals. Enterobacteriaceae resistant to 3rd generation cephalosporins are a great concern, as these are first-line drugs to treat infections caused by these common pathogens. Resistance to these antibiotics is mainly mediated by extended spectrum beta-lactamases (ESBLs), being CTX-M the most prevalent worldwide. The Lis river is a heavily polluted river in central Portugal, affected by several anthropogenic pressures including illegal waste discharges from piggeries. This study aims are: 1) to determine the prevalence of cefotaxime-resistant Enterobacteriaceae along the Lis river, in two years; 2) to determine the phylogenetic affiliation, clonality and antibiotic susceptibility profiles of blaCTX-M carriers isolated in Lis river; and 3) to characterize the diversity of blaCTX-M genes, their genomic context and association to mobile genetic elements. The Lis river presented a very low water quality in the 15 sampling sites, both in 2018 and 2019. Data from the 2018 campaign revealed the occurrence of cefotaxime-resistant bacteria in all sites, generally with higher rates in sites with lower water quality. In 2019 the same trend was observed but cefotaxime-resistant bacteria were not detected in three sites. From 147 cefotaxime-resistant isolates included in 9 genera, 68 (46%) carried the blaCTX-M gene and affiliated with 4 genera. Molecular typing revealed the presence of potentially clonal isolates in different sites and in the two years, suggesting survival of the strains in the river and probably continuous pollution inputs from the same sources. Clonal isolates collected in the same site and at the same time were excluded from further analysis. The remaining fifty-four isolates affiliated with Escherichia (n = 32), Klebsiella (n = 18), Enterobacter (n = 3) and Citrobacter (n = 1). From these, 79.6% showed a multiresistance profile with 2 isolates with reduced susceptibility to imipenem, a last-resort antibiotic. Seven different variants of blaCTX-M were found, namely blaCTX-M-1, blaCTX-M-3, blaCTX-M-15, blaCTX-M-32, blaCTX-M-55, blaCTX-M-14, blaCTX-M-27 and blaCTX-M-65, with blaCTX-M-15 being the most prevalent (52.5% of the isolates), as reported worldwide. blaCTX-M-65 was detected for the first time in Portugal. ISEcp1 was detected upstream the gene for all variants, and IS903 or orf477 were present in the downstream region. Results from this study reinforce the serious pollution problems in the Lis river. Sites with lower water quality also showed the highest resistance rates and the highest prevalence of the blaCTX-M gene, suggesting this gene as a pollution marker. The high number of blaCTX-M variants detected in Enterobacteriaceae, in contexts frequently reported in clinical isolates, suggest that the Lis river water may present relevant human health risks, which must be further assessed since this water is frequently used for irrigation, fishing and leisure activities.
Teixeira, Marco José Neto. "Biomonitoring of Ferreira and Sousa rivers using diatoms: comparison between morphological and molecular approaches." Master's thesis, 2021. http://hdl.handle.net/10773/30712.
Full textDois rios do norte de Portugal, os rios Sousa e Ferreira, com um passado recente de diferentes tipos de poluição e que percorrem zonas com elevado grau de alteração e densa população, foram analisados ecologicamente com base em dados biológicos (comunidades de diatomáceas), físico-químicos e hidromorfológicos. As diatomáceas são excelentes indicadores ecológicos da qualidade da água. Elas são amplamente distribuídas, apresentam alta diversidade de espécies e respondem rapidamente às pressões antropogénicas. A Diretiva Quadro da Água (DQA) fornece a base legal para a utilização deste bioindicador para avaliação da qualidade da água, através do cálculo de índices autoecológicos. Portugal adotou oficialmente a utilização do Indice de Polluosensibilité Spécifique (IPS), que após determinado, é convertido em Rácio de Qualidade Ecológica (RQE). Para o IPS, é necessária uma identificação morfológica e contagem das espécies de diatomáceas usando o microscópio. Esta abordagem requer alto conhecimento taxonómico e várias horas de análise. DNA metabarcoding combinado com técnicas de sequenciamento de alto rendimento (HTS), oferece uma alternativa promissora às metodologias clássicas, reduzindo tempo e custos. O objetivo deste estudo foi verificar que tipo de pressões afetam os rios e ribeiras no município de Paredes, desenvolver planos de melhoramento dos locais em estudo, comparar os valores de EQR obtidos para ambas as metodologias e verificar a eficácia e fiabilidade do DNA metabarcoding na avaliação biológica destes cursos de água, usando diatomáceas. Diatomáceas foram amostradas seguindo os padrões da DQA em dois rios e suas ribeiras (21 amostras) do município de Paredes, no outono de 2019. Todas as amostras foram submetidas paralelamente aos métodos moleculares e morfológicos. A metodologia molecular começou com a extração de eDNA, seguida pelo sequenciamento de DNA (Illumina MiSeq) usando o barcode de DNA rbcL de 312 bp. No software Mothur, as sequências obtidas foram analisadas produzindo Unidades Taxonómicas Operacionais (OTUs) atribuídas à biblioteca de referência R-Syst :: diatom. Inventários de comunidades de diatomáceas revelaram que apenas 24,2% das espécies eram comuns entre as metodologias, o que é explicado pela falta de espécies na biblioteca de referência. Em relação aos valores de RQE, os resultados indicaram uma boa correlação entre os métodos. A análise de PCO revelou um gradiente de classificação de qualidade em ambas as metodologias, apoiando a hipótese de que o DNA metabarcoding pode ser uma boa opção para avaliação da qualidade ecológica. No entanto, há trabalho a ser feito para que essa nova metodologia possa ser integrada na DQA. Dados biológicos, físico-químicos e hidromorfológicos evidenciaram impactos negativos nos cursos de água em áreas urbanizadas e agrícolas, exigindo a implementação de medidas e a consciencialização da população para os perigos envolvidos.
Mestrado em Ecologia Aplicada
Garcês, Andreia Manuela Vieira. "The impact of anthropogenic pressures on the mortality of wild animals in northern Portugal: a contribute to wild fauna preservation." Doctoral thesis, 2020. http://hdl.handle.net/10348/10352.
Full textNas últimas décadas, a população humana cresceu exponencialmente e quase três quartos da terra sem gelo são agora dominados por biomas antropogénicos. A presença e A atividade humana provocaram alterações nos ecossistemas, levando à sua destruição ou fragmentação. Estas mudanças têm enormes consequências negativas para as populações selvagens, direta e indiretamente, que em um estadio final podem levar à completa extinção de populações selvagens. Neste estudo, pretendemos obter uma visão geral sobre as consequências das ameaças induzidas pelo homem às populações de vertebrados selvagens (aves, mamíferos, répteis, anfíbios) no norte de Portugal, com base em dados recolhidos num Centro de Reabilitação de Animais Selvagens. O método de Partial Least Squares-Path Modelling (PLSPM) foi utilizado para determinar o impacto das pressões antropogénicas nessas populações. De 2008 a 2017, um total de 6058 aves selvagens nativas, 359 mamíferos selvagens, 66 répteis e 12 anfíbios foram admitidos no Centro de Recuperação de Animais Selvagens do Parque Biológico de Gaia (Portugal), mortos ou que morreram após a sua admissão. As regiões do norte de Portugal mais afetadas pelas pressões antropogénicas e onde foram recolhidos mais animais mortos pelas autoridades ou público foram Vila Nova de Gaia e Porto. A principal causa de internamento ocorreu devido a ferimentos, em todas as classes estudadas. A primavera e o verão foram as estações do ano em que mais animais foram admitidos. A principal causa de mortalidade foi traumatismo (principalmente traumatismo de origem desconhecida). Os resultados do PLS-PM identificaram como pressões mais significativas o número de pequenas e médias empresas nos municípios, tanto em mortes de origem traumática como não traumática. Embora o padrão de pesos seja semelhante, independentemente da causa geral da morte, as causas traumáticas parecem desempenhar um papel mais proeminente, dado os pesos maiores nas causas específicas relevantes (número de empresas). Os altos coeficientes de determinação (R2>0,8) revelam que a variação da mortalidade de aves selvagens é explicada em grande parte pela variação das pressões, o que indica uma relação de causa-efeito entre as variáveis independentes (pressões) e dependentes (mortalidade). O estudo da necropsia e as lesões observadas confirmaram os dados anteriores. No exame post mortem, os principais sistemas afetados foram os sistemas músculo-esquelético e tegumentar. As principais lesões observadas foram relacionadas a traumatismo e a maioria delas teve origem humana. A generalidade das lesões nas aves e morcegos esta relacionada ao impacto com infraestruturas, lesões causadas por armadilhas ou predação de animais domésticos (cão e gato). Em mamíferos estava particularmente relacionado com a colisão com veículos. Numa que realizámos num total de 170 animais selvagens (126 mamíferos e 44 aves) admitidos no Laboratório de Histologia e Anatomia Patológica da Universidade de Trás-os-Montes e Alto Douro de 2009-2019, vítimas de atropelamento, as lesões mais comumente observada foram: hemorragias, fraturas, hematomas e traumatismo craniano. O uso de um sofisticado método estatístico PLS-PM e sua incorporação em um Sistema de Informações Geográficas (SIG) revelou-se uma ferramenta importante para analisar o impacto na fauna silvestre de fatores ambientais e humanos. Os resultados obtidos indicam que há um impacto negativo substancial da atividade humana na mortalidade de animais selvagens. Os dados apresentados constituem uma ferramenta valiosa para promover a conservação da vida selvagem no norte de Portugal. Podem ainda fornecer uma visão da saúde dos ecossistemas, para ajudar a educar as pessoas a valorizarem a biodiversidade existente nessas áreas e encontrar novas estratégias para ajudar a recuperar e proteger muitas dessas espécies. No futuro, estudos mais abrangentes devem ser aprimorados em outras regiões do território nacional, compreendendo diferentes populações, a fim de identificar as principais pressões antropogénicas em diferentes áreas de estudo. É necessário, ao mesmo tempo, a integração de outras áreas do conhecimento, como genética populacional, patologia, ecologia são apenas alguns dos exemplos.
In the last decades the human population has grown exponentially and nearly three quarters of the land without ice is now dominated by anthropogenic biomes. Its presence and activity have led to altered ecosystems, leading to their destruction or fragmentation. These changes have enormous negative consequences on the wild populations, both directly and indirectly, that in a final stage can lead to the extinction of entire wild populations. In this study we aim to obtain a general view over the consequences of human-induced threats to the wild vertebrates (birds, mammals, reptiles, amphibians) populations in the Northern of Portugal, based on data collected from a Wildlife Rehabilitation Centre. The method of Partial Least Squares-Path Modelling (PLS-PM) was used to determine the impact of anthropogenic pressures in those populations. From 2008 to 2017 a total 6058 native wild birds, 359 wild mammals, 66 reptiles and 12 amphibians were admitted to the Wildlife Rehabilitation Centre of Parque Biológico of Gaia (Portugal), death or that died after admitted. Vila Nova de Gaia and Porto were the regions on Northern Portugal more affected by anthropogenic pressures and where more death animals were collected. The main cause of admission was due injured animals, in all the classes studied. Spring and summer were the seasons when more animals were admitted. The main cause of mortality was due to trauma (mostly trauma of unknow origin). The PLS-PM results identified as most significant pressures, the number of small and medium companies in the municipalities, both in traumatic and non-traumatic deaths. Although the pattern of weights is similar regardless of the general cause of death, traumatic causes seem to play a more prominent role given the larger weights in the relevant specific causes (number of companies). The high coefficients of determination (R2 > 0,8) reveal that the variance of wild bird mortality is largely explained by the variance of the pressures, which indicates a cause-effect relationship between the independent (pressures) and dependent (mortality) variables. The study of the necropsy and observed lesions confirmed the previous data. In the post-mortem exam the main system affected was the musculoskeletal and integument systems. The main lesions observed were related to trauma and most of them we could related to human origin. The majority of the lesions in the birds and bats were related to the impact with infrastructures, predation by domestic pets’(dog and cat) or entrapment. In mammals it was particularly related to collision with vehicles. In 170 wild animals (126 mammals and 44 birds) admitted to the University of Trásos-Montes and Alto Douro University Laboratory of Histology and Pathology, 2009-2019, victims of being run over, the most commonly observed injuries were: hemorrhages, fractures, bruises and head trauma. The use of a sophisticated statistical method PLS-PM and its incorporation into a Geographic Information System (GIS) revealed to be an important tool for analysing wildlife impacts of environmental and human factors. The results obtained indicate that there is a substantial negative impact of human activity on wild bird mortality. The data presented constitute a valuable tool to promote wildlife conservation in Northern Portugal. It may provide an insight in the health of ecosystems, in order to help educating people to value the biodiversity existent in these areas and find new strategies to help to recover and protect many of this species. In the future, more comprehensive studies should be enhanced within other regions of the national territory comprising different populations in order to identify the main anthropogenic pressures in different study areas. It is necessary at the same the integration of other knowledge areas such as population genetics, diseases, ecology and others.
Araújo, Susana Manso. "Emergence and dissemination of antibiotic resistance in the environment: origin of resistance genes and role of human activities." Doctoral thesis, 2021. http://hdl.handle.net/10773/32778.
Full textA resistência a antibióticos é uma preocupação crescente no que diz respeito à saúde pessoal e comunitária, à discrepância social no acesso à saúde e ao futuro do mundo natural. Este trabalho teve como objetivos compreender a origem dos determinantes genéticos da resistência a antibióticos (RA) em bactérias ambientais, bem como explorar o impacto da pressão antropogénica na evolução e dispersão da RA. O papel do género Shewanella como origem e reservatório de genes de RA foi avaliado através da análise de uma coleção de isolados ambientais e de genomas deste género, depositados em bases de dados públicas. A presença e o contexto genético do gene que codifica para a carbapenemase OXA-48 e a presença de genes qnrA foram avaliados. Estes genes foram detetados em várias espécies de Shewanella, nalguns casos pela primeira vez, sendo específicos para algumas destas espécies. Além disso, várias variantes novas foram identificadas neste trabalho. Sequências de inserção associadas à transferência de genes foram identificadas, fundamentando a sua contribuição na dispersão destes genes para outros grupos filogenéticos. O impacto da ação humana na disseminação da RA em compartimentos aquáticos foi abordado através da análise de vegetais consumidos crus e da água subterrânea utilizada para irrigação. Foram encontradas estirpes multirresistentes e com características de virulência, comuns aos dois ambientes, sugerindo a água de irrigação como origem da contaminação detetada em vegetais. A análise do genoma de algumas destas estirpes revelou determinantes de virulência, elementos genéticos móveis e genes de resistência, sugerindo um risco potencial para a saúde humana. Além disso, a diversidade e abundância de bactérias resistentes a carbapenemos foram avaliadas numa estação de tratamento de águas residuais, ao longo do processo que inclui um passo de desinfeção com radiação ultravioleta. O tratamento reduziu significativamente o número de bactérias, totais e resistentes a carbapenemos. Em águas não tratadas, foram detetadas estirpes de Enterobacteriaceae com o gene blaGES-5 -associado a integrões-, raramente encontrado no contexto clínico em Portugal. No efluente final foram encontradas bactérias intrinsecamente resistentes aos carbapenemos, nomeadamente Stenotrophomonas. Os resultados obtidos revelam evidência adicional no que diz respeito ao papel das bactérias ambientais como progenitores dos genes de RA, tal como o papel do homem na disseminação da RA nos compartimentos aquáticos. Este conhecimento é crucial para definir estratégias de mitigação deste problema, tanto no meio ambiente como na clínica.
Programa Doutoral em Biologia e Ecologia das Alterações Globais
Voerman, Sofietje Emma. "The spread of the native macroalga Caulerpa filiformis." Thesis, 2017. http://hdl.handle.net/10453/116915.
Full textMarine coastal systems are threatened by a wide range of anthropogenic pressures. Of particular concern are increased sediment and nutrient runoff. Moreover, hotspots of anthropogenic pressures are also where invasive species tend to be. The spread of invaders can directly translate to a loss of biodiversity and associated ecosystem services. There is a growing awareness that the spread of native species can have similar large impacts on biodiversity and ecosystem function to their famous non-native counterpart. Yet the how, when and why a native species transitions to a ‘native-invader’ (sensu Simberloff and Rejmánek 2010) are poorly known. This is especially true in the marine environment. In New South Wales (NSW), eastern Australia, a native green macroalga from the notorious Caulerpa genus, C. filiformis, has spread both inside and outside its native range. This study investigated the mechanisms that may have promoted the success of C. filiformis. The main aims were to increase our understanding on why this species has become so abundant, the habitat associations of the alga across large and local spatial scales, and the potential impacts on the seaweed community. In Chapter 2, large scale surveys showed that adult population abundance was related to sedimentation at multiple spatial scales, such as Reef Beach Index (RBI), reef width and the presence of a sediment veneer on top of the rocky reef (r+s habitat). In contrast, a low association with turf habitat was found, which is opposite to the observations for several other Caulerpa invaders. A model was proposed where the adult association with r+s represents an end stage of succession after outcompeting turfing alga. Moreover, it was shown that the seaweed community showed reduced morpho-functional richness in presence of C. filiformis. To test the proposed model, habitat association of the recruitment stage was investigated in Chapter 3. Surveys at several locations throughout the alga’s distribution showed that C. filiformis’ recruit abundance was found to be high on turfing algae habitat and not on r+s habitat. This positive association of the recruitment stage was observed for coralline forms of turfing alga, but not for filamentous forms. Those results support the model hypothesized. Additionally, the mechanisms behind this positive association were further explored in this chapter. A laboratory experiment revealed that the high association of C. filiformis’ recruits with coralline alga was explained by the increased attachment performance of C. filiformis fragments on this substrate. Namely, the increased structural complexity of coralline alga aided in rapid and strong attachment of fragments. Finally, mechanisms that may benefit post-recruitment processes of C. filiformis, and in particular the role of turf habitat, were investigated. With the use of long term field observations in Chapter 5, it was shown that established Caulerpa appears a poor competitor, and possibly requires further disturbance to spread. For example, a laboratory experiment showed that C. filiformis is highly tolerant to large sedimentation rates, aided by rapid morphological plasticity (Chapter 4). This may benefit the alga indirectly if sediment more negatively affects competitors. Moreover, increased sediment-nutrient availability was shown to promote growth rates, benefitting the alga’s competitive strength (Chapter 5). Overall, my thesis indicates that disturbance to native macrophytes indirectly promotes recruitment success by promoting turf habitat and that its continued spread is reliant on further disturbance to native communities – a model that has been demonstrated to invasive marine algae but not previously for a rapidly spreading native alga.
Lizcano, Javier. "Red Sea Acropora hemprichii Bacterial Population Dynamics under Adverse Anthropogenic Conditions." Thesis, 2012. http://hdl.handle.net/10754/244871.
Full textSoofi, Mahmood. "Effects of anthropogenic pressure on large mammal species in the Hyrcanian forest, Iran." Doctoral thesis, 2017. http://hdl.handle.net/11858/00-1735-0000-002E-E332-C.
Full textTeixeira, Zara Fani Gonçalves. "Resilience to land use induced impacts." Doctoral thesis, 2016. http://hdl.handle.net/10316/29520.
Full textA Directiva-Quadro da Água reforça o papel dos usos do solo na avaliação da qualidade da água, mas a utilização de dados de ocupação do solo, no que respeita a águas de superfície, restringe-se à estimativa dos padrões de uso do solo para a identificação de pressões provenientes de fontes de poluição difusas. O principal objetivo deste estudo é identificar especificidades da ocupação dos usos do solo na avaliação das mudanças de estado (Capítulo I), pressões (Capítulo I e II) e forças motrizes (Capítulo III e IV) da qualidade das águas de superfície. Para o efeito, usamos dados da bacia hidrográfica do Rio Mondego, uma bacia costeira localizada em Portugal, onde as mudanças socioeconómicas têm sido observadas desde a década de 1990 e que resultaram na perda de representatividade do setor agrícola e ganho do setor da construção. Apesar das mudanças, a agricultura mantém-se como uma fonte de pressão sobre as águas de superfície que, associada a modificações hidromorfológicas, causaram um declínio da qualidade ecológica do estuário do Mondego. Em 1998, a implementação de medidas de mitigação permitiu a recuperação do sistema, mas a monitorização identificou elevadas concentrações de nutrientes que pediam uma avaliação da sua proveniência. Por esta razão, a bacia do Rio Mondego, emerge como um caso de estudo com as condições necessárias para identificar aplicações mais amplas de dados de ocupação do solo no âmbito da identificação de forças motrizes e pressões sobre a qualidade da água. O Capítulo I estabelece a linha de base para este trabalho através da aplicação de indicadores de nutrientes e de substâncias-consumidoras-de-oxigénio para analisar a evolução das concentrações de amónia, nitrato e fosfato no estuário do Mondego entre os períodos 2003-2007 e 2012-2013 (ANOVA no software R); para analisar as diferenças entre as concentrações médias anuais de nutrientes nos rios tributários em 2012-2013 e as concentrações médias anuais encontradas em rios europeus em três períodos diferentes (1992, 2000, 2012); e para avaliar as diferenças na variabilidade das concentrações de nutrientes no estuário e nos tributários em 2012-2013 (ANOVA em software R). Adicionalmente, o Capítulo I avalia a dependência das concentrações de nutrientes estuarinas das entradas de água doce provenientes dos tributários, em dois períodos distintos. Procurou-se a relação linear entre as concentrações de nutrientes e a salinidade, a precipitação e a temperatura (regressão linear no software R). Os resultados revelam diferenças entre os intervalos de tempo e mostram uma dependência das concentrações de nutrientes das entradas de água doce proveniente dos rios, o que indica pressão de cargas de nutrientes sobre o estuário. No Capítulo II a pressão exercida pela descarga de nutrientes nos rios da bacia hidrográfica é avaliada utilizando dados de ocupação do solo. Analisa-se a adequação de métricas de paisagem para descrever a variabilidade espacial de nitratos em toda a bacia do rio Mondego usando dados sazonais de 2001 e 2006 (modelo linear misto - software R). Os resultados revelam que os padrões de ocupação do solo são descritores fracos da variabilidade espacial de nitratos na bacia do rio Mondego. No Capítulo III caracterizam-se as forças motrizes da qualidade da água usando como proxy os processos de mudança da paisagem. Os mapas CORINE de 1990, 2000 e 2006 são utilizados para analisar as mudanças entre oito categorias de ocupação, através de uma análise alargada de matrizes de transição. A magnitude da mudança e a consistência das transições revelam que as forças motrizes mais relevantes incluem categorias com baixa percentagem de ocupação, mas elevado efeito potencial nos processos hidrológicos. No Capítulo IV, reconhecendo que a precisão dos mapas pode influenciar a nossa percepção acerca das forças motrizes que atuam no sistema, aplica-se uma Análise de Intensidade para avaliar a adequação dos mapas CORINE como indicadores de mudanças de ocupação. Transições inconsistentes indicam erros de classificação que se poderiam propagar para outras aplicações que utilizam mapas de mudança de ocupação do solo. Analisando os resultados concluímos que ainda há espaço para o desenvolvimento de indicadores, nomeadamente indicadores de eficácia-de-políticas; que os dados de ocupação do solo como indicadores de pressão podem revelar o efeito, a longo prazo, da implementação de políticas; que a magnitude e a consistência dos processos de mudança de ocupação do solo revelam informações adicionais relativamente à avaliação das forças motrizes de transições de ocupação e que os mapas CORINE, apesar de serem dados de elevada qualidade, têm limitações de precisão facilmente identificadas através de uma Análise de Intensidade. Em relação à concentração de nutrientes, o nosso estudo sugere que são necessárias medidas de mitigação para reduzir as entradas de concentrações de fosfato para o estuário, de preferência por meio de políticas a nível europeu. The European Water Framework Directive enhances the role of land use in determining water quality of all waters, but the use of land cover data, regarding surface waters, is restricted to the estimation of land use patterns for the identification of pressures on surface waters from diffuse source pollution. The main goal of this study is to uncover specificities of land cover in the assessment of state changes (Chapter I), pressures (Chapt er I and II) and drivers (Chapter III and IV) of water quality of surface waters. For this purpose, we use data from the Mondego river basin, a coastal watershed in Portugal , where socio - economic changes observed since the 1990 s resulted in the loss of rep resentativeness from the agricultural sector and gain from the construction sector. Despite the observed changes, agriculture remained a source of pressure on surface waters which, associated with hydro - morphological modifications, caused a decline of the ecological quality of the Mondego estuary. In 1998, the implementation of mitigation measures enabled the recovery of the system but routine monitoring identified high concentrations of nutrients deserving further assessment to understand its sources. For this reason, the Mondego river basin, as a case study, provided conditions to reveal wider applications of land cover data within the assessment of drivers and pressures of water quality. Chapter I establishes the baseline for our research applying indicat ors of nutrients and oxygen - consuming - substances to analyze progress in the concentrations of ammonia, nitrate and phosphate in the Mondego estuary from a former period (2003 - 2007) to a recent period (2012 - 2 2013) (ANOVA in R software); to analyze difference s between the annual mean concentrations of nutrients in the tributary rivers in 2012 - 2013 and the average annual mean concentrations found in European rivers in three different periods (1992, 2000, 2012); and to evaluate differences in the variability of nutrient concentrations between the estuary and the tributaries in 2012 - 2013 (ANOVA in R software). Additionally, Chapter I evaluates the dependency of estuarine nutrient concentration s on riverine freshwater inputs in two different periods. A linear relat ionship between the nutrient concentrations and salinity, precipitation and temperature was sought (linear regression in R software). Altogether the results indicate differences between time intervals and are able to establish a dependency of nutrient conc entrations on riverine freshwater inputs, indicating pressure from nutrient loadings on the estuary. In Chapter II pressure from nutrient flushing on the river basin is evaluated using land cover data as an indicator. The suitability of landscape metrics t o describe the spatial variability of nitrate across the Mondego river basin is assessed using seasonal data from the years 2001 and 2006 (linear mixed model - R software). The results reveal that land cover patterns are weak descriptors of nitrate spatial variability in the Mondego river basin. In Chapter III driving forces of water quality are characterized using processes of landscape change as proxy. CORINE Land cover maps at 1990, 2000 and 2006 are used to analyze changes among eight categories throug h an extended analysis of transition matrices. The magnitude of change and consistency of transitions reveal that the most relevant driving forces from land transitions include categories with low percentage of occupation but high potential effect on hydro logical processes. In Chapter IV, acknowledging that the accuracy of maps may influence our perception of the main driving forces acting in the system, the Intensity Analysis approach is applied to evaluate the suitability of the CORINE land cover maps as indicators of land change. Inconsistent transitions reveal the misclassification errors that could propagate to other land cover change applications, as in the assessment of hydrological processes. Through the analysis of the results we conclude that there is still space for the development of indicators, namely policy effectiveness indicators; land cover data as indicator of pressure may reveal the effect of policies’ implementation in the long - term; the magnitude and con sistency of the processes of land change reveal additional information regarding the assessment of driving Abstract 3 forces from land transitions and that CORINE maps, though being high quality datasets, have accuracy limitations that are easily accessed through Int ensity Analysis. Regarding nutrient concentrations, our study suggests that mitigation measures, preferably through policies at the European level, are needed to reduce the inputs of phosphate concentrations into the estuary.
The European Water Framework Directive enhances the role of land use in determining water quality of all waters, but the use of land cover data, regarding surface waters, is restricted to the estimation of land use patterns for the identification of pressures on surface waters from diffuse source pollution. The main goal of this study is to uncover specificities of land cover in the assessment of state changes (Chapter I), pressures (Chapter I and II) and drivers (Chapter III and IV) of water quality of surface waters. For this purpose, we use data from the Mondego river basin, a coastal watershed in Portugal, where socio-economic changes observed since the 1990s resulted in the loss of representativeness from the agricultural sector and gain from the construction sector. Despite the observed changes, agriculture remained a source of pressure on surface waters which, associated with hydro-morphological modifications, caused a decline of the ecological quality of the Mondego estuary. In 1998, the implementation of mitigation measures enabled the recovery of the system but routine monitoring identified high concentrations of nutrients deserving further assessment to understand its sources. For this reason, the Mondego river basin, as a case study, provided conditions to reveal wider applications of land cover data within the assessment of drivers and pressures of water quality. Chapter I establishes the baseline for our research applying indicators of nutrients and oxygenconsuming-substances to analyze progress in the concentrations of ammonia, nitrate and phosphate in the Mondego estuary from a former period (2003-2007) to a recent period (2012) - 2013) (ANOVA in R software); to analyze differences between the annual mean concentrations of nutrients in the tributary rivers in 2012-2013 and the average annual mean concentrations found in European rivers in three different periods (1992, 2000, 2012); and to evaluate differences in the variability of nutrient concentrations between the estuary and the tributaries in 2012-2013 (ANOVA in R software). Additionally, Chapter I evaluates the dependency of estuarine nutrient concentrations on riverine freshwater inputs in two different periods. A linear relationship between the nutrient concentrations and salinity, precipitation and temperature was sought (linear regression in R software). Altogether the results indicate differences between time intervals and are able to establish a dependency of nutrient concentrations on riverine freshwater inputs, indicating pressure from nutrient loadings on the estuary. In Chapter II pressure from nutrient flushing on the river basin is evaluated using land cover data as an indicator. The suitability of landscape metrics to describe the spatial variability of nitrate across the Mondego river basin is assessed using seasonal data from the years 2001 and 2006 (linear mixed model - R software). The results reveal that land cover patterns are weak descriptors of nitrate spatial variability in the Mondego river basin. In Chapter III driving forces of water quality are characterized using processes of landscape change as proxy. CORINE Land cover maps at 1990, 2000 and 2006 are used to analyze changes among eight categories through an extended analysis of transition matrices. The magnitude of change and consistency of transitions reveal that the most relevant driving forces from land transitions include categories with low percentage of occupation but high potential effect on hydrological processes. In Chapter IV, acknowledging that the accuracy of maps may influence our perception of the main driving forces acting in the system, the Intensity Analysis approach is applied to evaluate the suitability of the CORINE land cover maps as indicators of land change. Inconsistent transitions reveal the misclassification errors that could propagate to other land cover change applications, as in the assessment of hydrological processes. Through the analysis of the results we conclude that there is still space for the development of indicators, namely policy effectiveness indicators; land cover data as indicator of pressure may reveal the effect of policies’ implementation in the long-term; the magnitude and consistency of the processes of land change reveal additional information regarding the assessment of driving forces from land transitions and that CORINE maps, though being high quality datasets, have accuracy limitations that are easily accessed through Intensity Analysis. Regarding nutrient concentrations, our study suggests that mitigation measures, preferably through policies at the European level, are needed to reduce the inputs of phosphate concentrations into the estuary.
Proulx, Bruno. "Utilisation de l’habitat et pressions anthropiques sur une population de rorquals à bosse (Megaptera novaeangliae) de Guadeloupe par suivi terrestre." Thèse, 2014. http://hdl.handle.net/1866/11887.
Full textThe Agoa sanctuary, a marine protected area (MPO) covering the exclusive economic zone (EEZ) in the French Caribbean, was created in 2010 to protect marine mammals and their habitats. It is known that the Caribbean islands are used from December to May by humpback whales (Megaptera novaeangliae) as a reproductive area. However, sparse information exists on the abundance, the behaviour, the distribution and the anthropogenic pressures on this species in the Caribbean and even less in the sanctuary. This thesis focuses on increasing scientific knowledge about this species’ use of a part of the Agoa Sanctuary and their interactions with human users of the MPO. Such knowledge may inform stakeholders’ (institutional and individual) decision-making towards implementation of appropriate conservation measures. A land-based survey of more than 300 hours, in 2012 and 2013, was carried out to determine the habitat use of, and anthropogenic pressures on, a population of humpback whales frequenting the surrounding water of the Pointe-des-Châteaux peninsula in Guadeloupe. This is the first land-based survey of this species in the French West Indies and one of the first in the Caribbean. The study area of approximately 264 square kilometres is one of the most visited areas by this species in the Guadeloupe archipelago. Using a theodolite, 107 trajectories (i.e. groups of whales) were recorded, representing 137.8 hours and 699 surfacings. Results show that the abundance was higher in March and April with a peak in the first week of April. The high proportion of calves in this population, mainly in March, suggest that the study zone is a nursing area. Overall movement patterns are not random and may possibly be dictated by the bathymetry. Furthermore, trajectories seem to converge close to the Pointe-des-Châteaux. The average movement is slow and oriented in the same direction as the dominant current to the west of the Pointe-des-Châteaux (i.e. ENE), except for mother and calf groups that swim faster in the opposite direction (i.e. WNW). Even if the anthropogenic pressure may be consided as moderate, a high proportion of surfacing is located in some of the main maritime traffic corridors. In addition, the shuttle corridor between Saint-Francois and Désirade island has the greatest relative risk of fatal collision. A reduced speed for the shuttle corridor would lower significantly the collision risk. These findings may lead to more extensive studies to better understand the ecology of this fascinating species.