Tesis sobre el tema "Marine ecosystems"
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Varkey, Divya Alice. "Marine ecosystem restoration with a focus on coral reef ecosystems". Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/30117.
Texto completoFolkersen, Maja. "Ecosystem Valuation of Vulnerable Marine Ecosystems in the South Pacific Islands". Thesis, Griffith University, 2018. http://hdl.handle.net/10072/385544.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Dept Account,Finance & Econ
Griffith Business School
Full Text
Boyd, Philip W. "Carbon fluxes in marine microbial ecosystems". Thesis, Queen's University Belfast, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334553.
Texto completoNEPOTE, ETTORE. "Multiple stressors affect coastal marine ecosystems". Doctoral thesis, Università Politecnica delle Marche, 2022. http://hdl.handle.net/11566/295443.
Texto completoMultiple stressors affect coastal marine ecosystems, whose effects are often largely unknown. This represents a crucial point, since the knowledge about the impacts caused by human activities are essential to apply adequate monitoring plans and mitigation strategy. Consequently, in this thesis four different human pressures were selected and investigated, in order to increase the available information. The first impact source selected is represented by desalination plants, for which the impact on macrobenthic assemblage was investigated. The results suggest that they do not cause alterations superimposed to the natural spatial variability of the macrofauna assemblage. This has been related to the small sizes of the plants. Similar results were obtained for the second stressor investigated (i.e., beach nourishment and beach re-profiling), which did not alter the spatial-temporal trend of the macro-meiofauna assemblage. Again, the lack of a significant impact was associated to the small size of the interventions. The third case study investigated the long term (40 years) changes (in m2) of seagrass meadow extension in the North Adriatic Sea. The results indicated that the two declines recorded were mainly correlated with two different drivers: urbanization and positive thermal anomalies respectively, which affected not only the meadow extension but also the species composition. Finally, the last pressure analyzed is the fishing with hydraulic dredging, which is extremely intensive in the Adriatic Sea. Specifically, here the effects of the decrease of fishing effort (of about 50%) imposed by the SARS-CoV-2 sanitary emergency was studied. From the results, it is evident a significant increase of bivalves, making the entire macrofauna assemblage significantly different from that present before the 2020. Overall, from these case studies, it is clear as a crucial role is played by the “size” of the human pressure. In addition, it is clear that in different ecosystems, when there is a noticeably decrease of human pressures, an appreciable partial recovery is possible.
Barausse, Alberto. "The integrated functioning of marine ecosystems". Doctoral thesis, Università degli studi di Padova, 2011. http://hdl.handle.net/11577/3421989.
Texto completoUn approccio ecosistemico alla gestione degli ecosistemi marini è l’obiettivo della recente Politica Marittima Integrata per l’Unione Europea, nota come Blue Book (2007), seguita a breve dalla nuova Direttiva Quadro sulla Strategia per l’Ambiente Marino (2008/56/EC). Vi si riconosce che, per esercitare una gestione efficace e sostenibile, si devono considerare i processi che si svolgono all’interno dei sistemi ecologici, sociali ed economici, e le interazioni fra tali sistemi. Tuttavia, una conoscenza quantitativa di tali processi e delle interazioni fra gli ecosistemi marini e i sistemi socio-economici è spesso scarsa, se non del tutto mancante. Lo scopo di questa tesi è comprendere meglio come le pressioni agenti su ecosistemi marini a larga scala portino a cambiamenti di stato. Ci si è concentrati su pressioni multiple, e sia su popolazioni che ecosistemi, ovvero sul funzionamento integrato degli ecosistemi marini. Sono state considerate sia pressioni di origine antropica come pesca ed apporti di nutrienti, che naturali come la variabilità climatica ed ambientale, basandosi principalmente sul caso di studio dell’Adriatico Settentrionale. L’Adriatico Settentrionale è un bacino del Mar Mediterraneo caratterizzato da abbondanza di dati utilizzabili a scopo scientifico, ed è un ecosistema eutrofico, intensamente sfruttato dalla pesca, fortemente influenzato dal clima, ed è sottoposto a pressioni antropiche da lungo tempo. Si sono utilizzate in maniera complementare differenti metodiche, fra cui modelli concettuali, l’analisi di reti ecologiche (Ecological Network Analysis) applicata ad un modello statico di rete trofica, l’analisi di serie temporali, modelli di popolazione, rassegna di dati storici, e meta-analisi di regolarità macro-ecologiche. I casi di studio includono specie di importanza commerciale come pesce azzurro o granchi, e predatori famosi come squali e razze. La principale conclusione di questo lavoro, basata sullo studio del funzionamento degli ecosistemi marini da molti punti di vista diversi, è che un approccio ecosistemico è realmente necessario nella gestione degli ecosistemi marini. Il motivo è che il funzionamento degli ecosistemi può essere ed è effettivamente influenzato da fattori multipli interagenti fra di loro, che includono (senza essere limitati ad esse) le pressioni esterne, e che agiscono sia dal basso (cioè dai livelli gerarchici inferiori) verso l’alto, che dall’alto (cioè dai livelli gerarchici superiori) verso il basso, ed a partire dall’interno (ovvero, dalle gerarchie intermedie) del sistema.
Gin, Karina Y. H. (Karina Yew Hoong). "Microbal size spectra from diverse marine ecosystems". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40155.
Texto completoTribot, Anne-Sophie. "Esthétique et biodiversité des écosystèmes sous-marins". Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT131/document.
Texto completoThe aesthetic value of landscapes and species is a central element for the conservation of biodiversity, since it involves the emotional and emotional dimensions of our relationship to nature. However, the links between biodiversity and aesthetic perception remains poorly studied and recognized within the ecosystem services framework.Following a first critical review, that described the conceptual and methodological bases of landscape aesthetics, three studies on underwater systems at different scales have been computed in order to better understand the link between the different facets of biodiversity and aesthetic perception.The results revealed that the link between biodiversity and aesthetic preferences is dependent on the scale of perception: at a multi-specific scale, biodiversity and species composition have a positive effect on aesthetic preferences, while preferences at a specific scale are disconnected to the ecological functioning of ecosystems.These results confirm the importance of aesthetic value in our perception of biodiversity, which could have major consequences in the way we protect our environment. The aesthetic experience based on the understanding of ecological functioning is proposed and described in order to promote an aesthetic perception relevant to ecological processes. Education to biodiversity based on engaged aesthetic is also proposed, in order to reconnect ecological needs and aesthetic preferences
Johnson, Theresa R. "Capturing Feedback in Complex Marine Ecosystems: Two Models". Fogler Library, University of Maine, 2001. http://www.library.umaine.edu/theses/pdf/JohnsonTR2001.pdf.
Texto completoBrotz, Lucas. "Changing jellyfish populations : trends in large marine ecosystems". Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/38193.
Texto completoZOBRIST, KURT DANIEL. "COASTAL HARMONY: BETWEEN MARINE ECOSYSTEMS AND COASTAL DEVELOPMENT". University of Cincinnati / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1082747560.
Texto completoZobrist, Kurt D. "Coastal harmony between marine ecosystems and coastal development /". Cincinnati, Ohio : University of Cincinnati, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=ucin1082747560.
Texto completoDENARO, Giovanni. "Stochastic models for phytoplankton dynamics in marine ecosystems". Doctoral thesis, Università degli Studi di Palermo, 2014. http://hdl.handle.net/10447/91323.
Texto completoau, keulen@murdoch edu y Michael van Keulen. "Water Flow in Seagrass Ecosystems". Murdoch University, 1998. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20040518.91242.
Texto completoLockerbie, Emma Margaret. "A decision tree framework for assessing status of exploited marine ecosystems under changing environmental conditions". Doctoral thesis, University of Cape Town, 2018. http://hdl.handle.net/11427/27996.
Texto completoHenderson, Christopher. "Seascape Context and Marine Reserves in Seagrass Ecosystems: Managing Harvested Fish Communities". Thesis, Griffith University, 2017. http://hdl.handle.net/10072/365948.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Griffith School of Environment
Science, Environment, Engineering and Technology
Full Text
Lucea, Sureda Anna. "Elemental Stoichometry in Nutrient Pools in Oligotrophic Marine Ecosystems". Doctoral thesis, Universitat Politècnica de Catalunya, 2004. http://hdl.handle.net/10803/6387.
Texto completoLa estequiometria dels nutrients a l'oceà s'ha examinat al Mar Mediterrani i a l'Oceà Atlàntic subtropical, mentre que la zona costenera del Mar Mediterrani ha servit per estudiar aquestes relacions sota l'influència d'aports terrestres.
En el segon capítol de la tesi es descriuen patrons meridionals del fluxe de nitrogen i fósfor vers la capa biogènica de l'Oceà Atlàntic Central. La raó promig entre el fluxe difusiu del nitrogen inorgànic dissolt (DIN) i del fósfor (DIP) es mostra similar a la raó de Redfield al llarg de l'Oceà Atlàntic Central, però tendeix a valors per sota dels establerts per Redfield a la part sud del trajecte i superiors a la raó de Redfield al centre del gir sudtropical. La raó N:P del fluxe difusiu i la raó N:P dels nutrients dissolts inorgànics en la capa biogènica es troben fortament correlacionats, mentre que no existeix cap correlació amb els valors de la raó N:P de les aigües intermitges. Els resultats trobats en aquest capítol de la tesi indiquen que la recirculació vertical de nutrients a la capa biogènica de l'oceà Atlàntic Central és capaç d'operar amb raons estequimètriques que difereixen de Redfield i per tant els components biogènics i biolítics s'adapten a les variacions locals de la raó de Redfield. La hipòtesis que existeixen raons estequiomètriques previsibles en la reserva oceànica de material dissolt orgànic que es troben en equilibri amb la reserva del material particulat orgànic i dissolt inorgànic, es corrobora en el tercer capítol d'aquesta tesi. La majoria del carboni orgànic present en aigües oligotrofiques del Mediterrani estratificat es troba en forma d'orgànic dissolt, mentre que el POC (carboni orgànic particulat) representa un percentatge menor. El nitrogen i fósfor orgànic dissolt que comprenen el 50-80% del "pool" total de P i N a la capa biogènica, decreix en percentarge a la capa biolítica. S'ha comprovat una distribució uniforme del nitrogen disolt total (TDN). L'increment en el percentatge de N inorgànic disolt i el decreixement en percentatge de N orgànic dissolt amb la fondària, és un indicador clar de l'equilibri dinàmic que existeix entre les reaccions bioquímiques entre les reserves oceàniques. Mitjançant un sistema de balanços, s'estableix un intercanvi de nutrients (exportació-importació) entre els pools dissolt orgànic i dissolt inorgànic en el sistema. S'ha comprovat que el fluxe de nitrogen orgànic dissolt (DON) excedeix al fluxe difusiu de nitrogen inorgànic i per tant els aports atmosfèrics i terrestres són importants en aquesta regió.
En el quart capítol de la tesi es descriu el lligam existent entre el component pelàgic i els component del bentos d'una àrea litoral del Mar Mediterrani, és a dir un compartiment anabolic que produeix matèria orgànica i un de catabolic que actúa com agent oxidant de la reserva de matèria orgànica del sistema. El compartiment pelàgic es mostra heterotrofic. Al mateix temps, existeix una contribució important de material terrestre als sediments. Per contra, el compartiment bentònic és autotrofic on el dèficit en la producció grossa es compensa amb l'excés de producció neta del sistema. Mitjançant la quantificació simultànea dels fluxes anuals de sedimentació per al C, N, P i Si així com dels fluxes sediment-aigua de les espècies orgàniques i inorgàniques dissoltes, s'ha establert un sistema de balanços de matèria del sistema. El compartiment bentonic es configura com a sumider o exportador de matèria orgànica, degut als aports terrestres de carboni en el sistema.
Els patrons de distribució de nutrients derivats dels resultats dels capítols anteriors es comproven mitjançant un experiment d'addició de nutrients. En el capítol cinquè d'aquesta tesi s'estudien els canvis en la distribució de nutrients en les diferents reserves nutricionals d'un sistema quan es troba sotmès a aports controlats de nutrients. S'ha comprovat que, mentre el tamany relatiu de la reserva de nutrients inorgànics dissolts no varia amb l'increment de nutrients en el medi. Hi ha una tendència a l'increment del tamany relatiu de la reserva del material particulat, paral.lela a un decreixement simultani de la reserva de material dissolt orgànic. Aquest experiment contribueix a verificar el paper del DOM (matèria dissolta orgànica) com a principal reserva nutricional en sistemes oliogotròfics.
The stoichiometric ratios are powerful tools to model basic biogeochemical patterns of the sea when the fluxes of a single element are known. It is, therefore essential to understand the full implications of variable stoichiometries to predict the effect of the living components of the ocean on biogeochemical processes. Here, the stoichiometry between C, N, P and Si in different chemical pools (particulate and dissolved organic and dissolved inorganic matter) were examined in contrasting oceanic and littoral ecosystems, and the changes in nutrient partitioning in response to nutrient inputs was tested through experimental research.
In the Central Atlantic Ocean, the average ratio between dissolved inorganic nitrogen and phosphorus in the estimated vertical diffusive fluxes was similar to the Redfield ratio, but tended to be above the Redfield ratio at the center of the South subtropical gyre. The N:P supply ratio and the N:P ratio of dissolved inorganic nutrients in the biogenic layer were strongly correlated, but were not positively correlated to that in the intermediate waters. The vertical nutrient conveyor belt of nutrients in the upper waters operates relatively independently of the underlying waters in the Central Atlantic, so that both the biogenic and the biolythic components should be able to adapt to local variation about the Redfield ratio.
In the stratified NW Mediterranean Sea, the stoichiometry between dissolved inorganic, organic and particulate organic matter pools indicated an excess nitrogen relative to phosphorus, particularly in the biolythic layer, as well as a general silicate deficiency relative to both N and P. Most (> 80 %) of the organic carbon was present as dissolved organic carbon, with POC representing a minor percent of total organic C throughout the water column. The increasing C/N ratio of DOM with depth indicates that N is recycled faster than C in the DOM. There exists a dynamic equilibrium between the biological transformations between these pools with depth, with a dominance of DON production in surface waters and remineralization in the underlying layers, from which dissolved inorganic nitrogen is re-supplied to the biogenic layer.
Alocthonous N inputs must be important in the region since the downward DON flux exceeded the diffusive DIN supply.
The coupling between anabolic and catabolic compartments of a littoral area in the NW Mediterranean Sea are characterized. The pelagic compartment was heterotrophic, supported by significant allochthonous inputs of land material, whereas the benthic compartment was autotrophic, with the excess net benthic community production balancing the deficit in pelagic community production, leading to a system in metabolic equilibrium. Sedimentary inputs of phosphorus and silicon were compensated by sediment release of phosphate and silicate, whereas nitrogen was lost or accumulated in the sediment compartment. Carbon inputs to the benthic compartment also exceeded requirements, due to the allocthonous subsidies to the system, so that the benthic compartment stored or exported organic carbon.
Experimental nutrient additions lead to a parabolic change in C/N and C/P ratios in the dissolved organic matter with increasing nutrient inputs. The relative size of the dissolved inorganic nutrient pools did not vary, but there was a tendency towards an increase in the relative size of the particulate pool at the expense of a decrease in the relative importance of DOM as a reservoir of N, P and C, with increasing nutrient inputs.
The relative importance of different nitrogen pools was examined in relation to the total nutrient stoichiometry of the oligotrophic system. The ratio of dissolved inorganic nutrients reported in the research presented is indicative of a general deficiency in nitrogen compared to the global ratios reported in literature. The dissolved organic matter was highly depleted in P relative to N and C at all locations investigated and the resulting POC:PON ratio (11.7) of this study in the particulate pool deviates greatly from the literature values which approximates Redfield value (5.5-6). The shift of the dominance of DON towards PON at TOC/TN values higher than 20 on the oligothrophic areas of the study, gives evidence of increasing carbon export fluxes in a system dominated by particulate pool and points to the effect of the biota on the gradient-driven export to sinking carbon fluxes in the ocean.
Strand, Sarah Elise. "Stable Isotope Biogeochemistry of South Florida Coastal Marine Ecosystems". FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1737.
Texto completoMarshall, Laura. "Statistical developments for understanding anthropogenic impacts on marine ecosystems". Thesis, University of St Andrews, 2012. http://hdl.handle.net/10023/3172.
Texto completoKwiatkowski, Lester. "Modelling environmental impacts on marine ecosystems and coral reefs". Thesis, University of Exeter, 2013. http://hdl.handle.net/10871/14931.
Texto completoSanmartí, Boixeda Neus. "Biological interactions and resilience of seagrass ecosystems". Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/672259.
Texto completoEl nostre món està sotmès a un ampli ventall de forces que tendeixen a provocar canvis. En aquest context, entendre com la biosfera resisteix, absorbeix o és alterada per aquestes forces resulta una qüestió candent, especialment per l'ecologia. Al respecte, dos conceptes ecològics esdevenen essencials: la resiliència i les interaccions biològiques. La resiliència és la capacitat de persistència o recuperació que tenen els ecosistemes sotmesos a estrès o pertorbacions. Les interaccions entre espècies (efectes de l'existència d'una espècie sobre la fitness d'una altra) contribueixen al manteniment de les funcions ecosistèmiques i, en un cert sentit, constitueixen l'arquitectura de la biodiversitat. A més, la resiliència dels ecosistemes depèn , en gran part, d’aquestes interaccions. Aquesta tesi és un intent d’aprofundir en els aspectes esmentats a través d'una sèrie de casos d’estudi en ecosistemes d’angiospermes marines. Concretament, el que fem és estudiar com els ecosistemes d’angiospermes marines responen a les forces causants de canvis, com aquestes respostes vénen mitjançades per canvis en la interacció entre espècies, i provar d'esbrinar els mecanismes que permeten la coexistència d’espècies que es troben vinculades per interaccions positives i negatives. La nostra aproximació es basa tant en observacions com en experiments en el camp. El Capítol 1 mostra com un increment de matèria orgànica en el sediment debilita el mutualisme entre el bivalve Loripes lucinalis i l’angiosperma marina Cymodocea nodosa. El mecanisme implicat que es proposa per explicar-ho està relacionat amb la plasticitat morfològica de la planta. Així, un increment en la matèria orgànica del sediment (i, probablement, l’anòxia que se'n segueix), fa que la planta modifiqui la morfologia de les seves arrels, que esdevenen molt menys ramificades i fan disminuir per tant la disponibilitat d'hàbitat per als bivalves. Una debilitació del mutualisme pot, potencialment, disminuir la resiliència d’aquests ecosistemes a l’eutrofització i, per tant, comprometre la seva persistència. El Capítol 2 descriu una cascada de facilitació en la qual l’angiosperma marina C. nodosa afavoreix l’abundància del gran bivalve Pinna nobilis, que ajuda a incrementar l'abundància de la garota Paracentrotus lividus, que al seu torn consumeix l’angiosperma. Suggerim que la persistència d’aquest sistema de tres espècies, aparentment inestable (tres interaccions concatenades circularment, dues de positives i una de negativa) es basa en què la interacció negativa (l’efecte de les garotes sobre l’angiosperma) té un abast molt limitat, probablement degut tant al seu comportament alimentari com a les defenses de la planta enfront de l'herbivorisme. Els Capítols 3 i 4 mostren que les espècies de creixement ràpid, com ara C. nodosa, són altament resilients a l'estrès o a les pertorbacions quan aquestes afecten només les parts aèries de les plantes (defoliació parcial o total), recuperant-se ràpidament (dues setmanes) després d'una pertorbació puntual en el temps. C. nodosa mostra diversos mecanismes de tolerància a la defoliació, com ara el creixement compensatori, la reassignació de recursos interns i l’increment en la taxa de formació de nous mòduls. Tanmateix, quan les pertorbacions provoquen la pèrdua de les parts subterrànies (rizomes i arrels), la recuperació és molt més lenta, i triga fins a dos anys. A més, aquesta recuperació depèn de les característiques de la pertorbació com ara la mida de l'àrea afectada i l’època de l'any en què es produeix. En general, aquesta tesi ha contribuït a comprendre millor les respostes dels ecosistemes als canvis. Hem pogut documentar alguns processos que permeten la coexistència entre espècies, així com mecanismes de resiliència específics que esdevenen ecosistèmics quan es manifesten en espècies fundadores d'hàbitat. També hem demostrat com els canvis, més enllà d'afectar espècies individuals més o menys emblemàtiques, poden provocar alteracions de formes més subtils, com ara erosionant la seva resiliència mitjançant la modificació d’interaccions biològiques. Els avenços en totes aquestes direccions complementàries i interrelacionades són crucials per a gestionar i preservar els ecosistemes i evitar el seu possible col·lapse.
Yau, Hok-wai Horace. "The derivation of sediment quality guidelines for protecting marine ecosystems /". View the Table of Contents & Abstract, 2005. http://sunzi.lib.hku.hk/hkuto/record/B34739464.
Texto completoChronopoulou, Panagiota-Myrsini. "Impact of crude oil on bacterial communities in marine ecosystems". Thesis, University of Essex, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531559.
Texto completoSagerman, Josefin. "Marine seaweed invasions : Impacts and biotic resistance in native ecosystems". Doctoral thesis, Stockholms universitet, Institutionen för ekologi, miljö och botanik, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-116788.
Texto completoAt the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: Manuscript.
Alien-native trophic interactions: consequences for invasion success and ecosystem effects of invasions
Yau, Hok-wai Horace y 丘學緯. "The derivation of sediment quality guidelines for protecting marine ecosystems". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B45013317.
Texto completoQuental-Mendes, Rui. "Modelling marine ecosystems : a viral solution to the DOC enigma". Thesis, University of Southampton, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307149.
Texto completoValbuena-Gonzalo, Carlos. "The Importance of Trait Mediated Indirect Interactions in Marine Ecosystems". Thesis, Umeå universitet, Institutionen för ekologi, miljö och geovetenskap, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-163445.
Texto completoFricke, Lorena [Verfasser]. "The Economics of Regime Shifts in Marine Ecosystems / Lorena Fricke". Kiel : Universitätsbibliothek Kiel, 2016. http://d-nb.info/1096220830/34.
Texto completoOPRANDI, ALICE. "CONSERVATION STATUS AND TRAJECTORIES OF CHANGE IN MARINE COASTAL ECOSYSTEMS". Doctoral thesis, Università degli studi di Genova, 2020. http://hdl.handle.net/11567/1006699.
Texto completoBarbato, M. "POLLUTED MARINE ECOSYSTEMS: RESERVOIR OF MICROBIAL RESOURCES FOR HYDROCARBON BIOREMEDIATION". Doctoral thesis, Università degli Studi di Milano, 2014. http://hdl.handle.net/2434/247225.
Texto completoCropp, Roger Allan y R. Cropp@griffith edu au. "A Biogeochemical Modelling Analysis of the Potential For Marine Ecosystems to Regulate Climate By the Production of Dimethylsulphide". Griffith University. Australian School of Environmental Studies, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030703.101310.
Texto completoCropp, Roger Allan. "A Biogeochemical Modelling Analysis of the Potential For Marine Ecosystems to Regulate Climate By the Production of Dimethylsulphide". Thesis, Griffith University, 2003. http://hdl.handle.net/10072/367734.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Australian School of Environmental Studies
Full Text
Edwin, S. "Mangrove ecosystem biodiversity: A case study". Thesis, Central Marine Fisheries Research Institute, 2002. http://eprints.cmfri.org.in/11057/1/Edwin%20S..pdf.
Texto completoValls, Mir Maria. "Trophic Ecology in Marine Ecosystems from the Balearic Sea (Western Mediterraniean)". Doctoral thesis, Universitat de les Illes Balears, 2017. http://hdl.handle.net/10803/461496.
Texto completoHutchinson, David John. "Institutional fit in tropical ecosystems : a test using marine protected areas". Thesis, University of East Anglia, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.405692.
Texto completoWallace, S. Scott. "Fisheries impacts on marine ecosystems and biological diversity : the role for marine protected areas in British Columbia". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ46442.pdf.
Texto completoElisa, Bergami. "Polystyrene nanopaticles and their impact on marine ecosystems: accumulation, disposal and toxicity in Mediterranean and Antarctic marine species". Doctoral thesis, Università di Siena, 2018. http://hdl.handle.net/11365/1055530.
Texto completoBosch, Orea Cristina. "Evaluation of biotoxins in marine ecosystems by new analytical and biological strategies". Doctoral thesis, Universitat de Barcelona, 2021. http://hdl.handle.net/10803/670662.
Texto completoLa tesis doctoral presenta el desarrollo de diversas metodologías analíticas para el análisis de biotoxinas marinas en agua de mar. Las técnicas utilizadas son la cromatografía líquida de alta eficacia acoplada a la espectrometría de masas de alta resolución. El objetivo de estos métodos de análisis es su utilización en el estudio de las biotoxinas marinas en el medio marino, así como su aplicación para la temprana detección de estos compuestos cuando están a bajas concentraciones, con el fin de anticiparse a la posible formación de eventos de floraciones algares nocivas donde la concentración de las biotoxinas podría ser muy elevada y provocar impactos negativos en el ecosistema y en las actividades de maricultura. El desarrollo analítico se ha realizado evaluando la precisión, exactitud, selectividad y sensibilidad de los métodos. Dado que las propiedades físico-químicas de los diferentes grupos de biotoxinas son muy diversas, se han tenido de desarrollar tres metodologías diferentes. La primera etapa para todas consiste en un tratamiento de muestra ya que es esencial eliminar posibles interferencias en la muestra para su posterior análisis mediante las dichas técnicas instrumentales, por lo que las biotoxinas fueron extraídas del agua de mar y concentradas. Primeramente, se filtra el agua de mar y se separa la porción de materia en suspensión y la parte del filtrado para ser tratadas y analizadas por separado. La extracción de las biotoxinas de la porción de materia en suspensión se realiza con metanol y se asiste con ultrasonidos. La fracción del filtrado se somete a una extracción en fase sólida en diferentes condiciones dependiendo del grupo de toxinas. El análisis de los extractos, se realiza mediante cromatografía liquida de alta eficacia acoplada a espectrometría de masas de alta resolución mediante la ionización por electroespray. La separación de los compuestos más polares, se realizó mediante cromatografía líquida de interacción hidrofílica mientras que para los más apolares fue de tipo fase inversa. La adquisición utilizada en la espectrometría de masas fue mediante la combinación de un barrido completo en alta resolución y la fragmentación de los iones precursores, tipo tándem de masas, para cada una de las toxinas a resolución más baja. Una vez validadas, las tres metodologías se emplearon en el estudio de biotoxinas en el mar Mediterráneo, concretamente en el litoral catalán y murciano. Las biotoxinas más apolares se investigaron a lo largo de la costa catalana, mediante muestras recolectadas en playas públicas y puestos deportivos en diferentes localidades. El 88 % de esas muestras había una de las toxinas más frecuentemente hallada en el mar Mediterráneo, el ácido okadaico, el cual estaba en rangos de concentración de entre 2 ng/L y 9,5 µg/L. Por otro lado, el ácido domoico, se estudió en la zona de la desembocadura del rio Ebro, que consta de una zona de humedales y dos bahías donde se llevan a cabo actividades de maricultura. Su presencia destacó en las bahías especialmente en las muestras colectadas en verano, aunque la concentración más alta llegó a los 69,5 ng/L. Finalmente, las biotoxinas más polares se analizaron en aguas de la laguna salada del Mar Menor, en Murcia. Sin embargo, no se detectó la presencia de ninguna. Por otro lado, una de los métodos se utilizó para la validación de un inmunoensayo previamente desarrollado, capaz de detectar y cuantificar cinco grupos de contaminantes en agua de mar, siendo uno de ellos una biotoxina, el ácido domoico. Al immunoensayo se le añadió una etapa de tratamiento de muestra en que se pudieron concentrar los diferentes compuestos y conseguir así una detectabilidad a concentraciones muy bajas, del rango de los ng/L. Para concluir, se podría decir que los métodos desarrollados proporcionan mucha sensibilidad y selectividad en el análisis de biotoxinas marinas en agua de mar y que además, gracias a la alta resolución de las técnicas instrumentales, se podría estudiar la caracterización de compuestos nuevos.
Stoner, Elizabeth W. "Human-driven Benthic Jellyfish Blooms: Causes and Consequences for Coastal Marine Ecosystems". FIU Digital Commons, 2014. http://digitalcommons.fiu.edu/etd/1516.
Texto completoHicks, Natalie Ruth. "Impact of environmental change on primary production in model marine coastal ecosystems". Thesis, University of St Andrews, 2011. http://hdl.handle.net/10023/3143.
Texto completoWillaert, Tom. "Valuation of marine and coastal ecosystems: The role of ecological-economic modeling". Master's thesis, NSBE - UNL, 2014. http://hdl.handle.net/10362/11539.
Texto completoThe main objective of this work project is to highlight the progress made in the field of ecological-economic modeling of marine and coastal ecosystems, in particular, by stressing the need to incorporate more realistic biology as well as the spatial dimension in integrated models for sustainable coastal management. The discussion undertaken is based on a recent application of an integrated ecological-economic model that is spatially explicit by Altman et al. (2012), and should provide guidance to the GOI’s research project to the Peniche-Nazaré study site in the Portuguese coast.
Stoffle, Richard W. y David Halmo. "Satellite Monitoring of Coastal Marine Ecosystems: A Case from the Dominican Republic". University of Arizona, 1991. http://hdl.handle.net/10150/272833.
Texto completoJacob, Céline. "Approche géographique de la compensation écologique en milieu marin : analyse de l’émergence d’un système de gouvernance environnementale". Thesis, Montpellier 3, 2017. http://www.theses.fr/2017MON30001/document.
Texto completoMy research topic is multidisciplinary combining geography, ecology and economics and addressing the efficiency of current marine offset practice. Building on a state of the art of current practice, I am working on a more prospective approach (compared to current research on mitigation targeting terrestrial ecosystems). By offset, I am referring to legal mitigation that consists in avoiding – reducing – offsetting adverse impacts of development projects such as dredging, port infrastructure, oil exploration, marine aggregate extraction, beach nourishment, etc. on marine and coastal ecosystems. Based on a review of around fifty French marine Environmental Impact Assessments (EIAs), I analyzed the assessment of impacts, the use of offset sizing methods (robust method to assess ecological losses due to development projects and ecological gains created by offset measures) and the kind of measures proposed. Within these EIAs, sizing methods were seldom used and the very few measures suggested to offset residual impacts could be questioned in terms of equivalency and appropriateness. These measures were either ecological engineering techniques (such as seagrass or coral restoration), management measures (used to reduce pressure on the impacted ecosystems through the funding of management measures in Marine Protected Areas for example) or even knowledge acquisition. Thus, I am also looking at the efficiency of ecological engineering techniques on marine and coastal ecosystems. My research mainly focuses on the offset of authorized impacts but could also deals with some aspects of the offset of accidental damages
Engelhard, Sarah Laure. "Marine Spatial Connectivity in Theory and Conservation". Thesis, Griffith University, 2017. http://hdl.handle.net/10072/365470.
Texto completoThesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Grifffith School of Environment
Science, Environment, Engineering and Technology
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Moffitt, Sarah Evelyn. "Marine ecosystems and climate change| Ecological and oceanographic lessons from the recent deglaciation". Thesis, University of California, Davis, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3646353.
Texto completoEvidence from modern oceanography, climate simulations of future conditions, and paleoceanographic archives motivates the need to reconstruct Oxygen Minimum Zone (OMZ) changes during past events of abrupt climate warming and carbon system perturbation. This dissertation focuses on the loss of oxygen in the Eastern Pacific Ocean through the most recent deglaciation event, in order to understand the spatial magnitude of oceanic deoxygenation and to quantify disturbance and recovery dynamics in seafloor biodiversity. New evidence from a shallow post-glacial sediment core (MV0811-15JC) from Santa Barbara Basin, California, USA, demonstrates the remarkable shallowness of OMZ influence to within ~300 meters from the ocean surface during the recent deglaciation. This site confirms that paleoceanographic reconstructions of hypoxia from Santa Barbara Basin are a product of regional expansions and contractions of the OMZ. Microfossil archives of seafloor metazoans (Echinodermata, Arthropoda and Mollusca; >5,350 individuals) from site MV0811-15JC demonstrate the extreme sensitivity of seafloor metazoan communities to abrupt (<100 year) deoxygenation of the Eastern Pacific, and expand known timescales of biological recovery by one order of magnitude, from <100 years to >1,000 years. Molluscan communities provide a complex interpretive window with which to understand environmental change through the deglaciation. Chemosynthetic and symbiotic molluscs numerically dominate the faunal record, yet these extremophiles do not strongly co-occur, indicating the development of heterogeneous extreme environments as a result of hydrographic regimes and the development of sulfur oxidizing bacterial mats. These analyses reveal that previous deoxygenation events dwarf modern scales of ecological disturbance, and illustrate the role that climate and oceanographic change have in driving long-term successional oscillations in ocean ecosystems. More broadly, the global inventory of deglacial and post-glacial sediment records exhibits remarkable synchrony in reconstructing subsurface hypoxia, and reveals that OMZs across the entire Eastern Pacific margin expanded and intensified concurrently. Most strikingly, these results uncover the capacity for large contiguous swaths of the ocean interior to rapidly lose dissolved oxygen, resulting in the expansion of OMZ ecosystems and the compression of surface ocean oxygenated ecosystems. Climate-forced changes to ocean systems introduce a scale of environmental disturbance that only has analogue in the rapid warming events of past climates. These critical analogues serve to illustrate the scale and ecological consequences of climate-forced deoxygenation.
Camus, Lionel Andre Yves. "Biomarkers relevant to oil and gas industrial activities in low temperature marine ecosystems". Thesis, University of Plymouth, 2001. http://hdl.handle.net/10026.1/1080.
Texto completoArimitsu, Mayumi. "The influence of glaciers on coastal marine ecosystems in the Gulf of Alaska". Thesis, University of Alaska Fairbanks, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10146002.
Texto completoGlacier runoff (i.e., meltwater and rainwater discharged at the glacier terminus) provides about half of the freshwater discharge into coastal margins of the Gulf of Alaska, where contemporary glacier melting rates are among the highest in the world. Roughly 410 billion metric tons of glacier runoff enter the Gulf of Alaska each year. With freshwater discharge volumes of that magnitude, I hypothesized that glacier runoff has both direct and indirect effects on the receiving coastal marine ecosystems that support rich food webs, abundant and diverse marine communities, commercial fisheries and tourism industries. To examine the influence of glacier runoff on coastal marine ecosystems, I focused on three questions: 1) How does the marine food web respond to physical and biological gradients induced by glacier runoff? 2) What is the contribution of riverine organic matter (OM) and ancient carbon resources in glacier runoff to marine food webs from plankton to seabirds? and 3) How does the influence of glaciers on coastal marine ecosystems differ at small to large spatial and temporal scales? I measured physical, chemical and biological indices within four fjord systems along the eastern Gulf of Alaska coast. In chapter one I used geostatistics as well as parametric and non-parametric models to demonstrate a strong influence of glacier runoff on ocean conditions and coastal food webs across all the fjord systems. In chapter two I used isotopes (δ 2H, δ13C, δ15N, and δ 14C) to trace riverine OM and ancient carbon resources into the marine food web. This work included the development of a novel multi-trophic level 3-isotope Bayesian mixing model to estimate the proportion of allochthonous resources in animal tissues. Mean estimates from 14 species groups spanning copepods to seabirds ranged from 12–45 % riverine OM source assimilation in coastal fjords, but ancient carbon use by marine food webs was low. In the third chapter I synthesized information on the scale-dependent influence of glaciers on lower-trophic level productivity, predator-prey interactions and ways that humans may be affected by anticipated changes in glacier coverage. This contemporary understanding of glacier influence on coastal ecosystems aligns with paleoenvironmental evidence suggesting that over geological time scales glaciers have and will continue to shape marine ecosystems in the Gulf of Alaska.
Palladino, Giorgia <1994>. "Impact of anthropogenic stressors on the microbial communities in marine holobionts and ecosystems". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2022. http://amsdottorato.unibo.it/10270/4/PhD_thesis_Giorgia_Palladino.pdf.
Texto completoGunasekara, Sandya Nishanthi. "Governance of the bay of Bengal large marine ecosystem through ecosystem-based fisheries management". Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/213832/1/Sandya%20Nishanthi_Gunasekara_Thesis.pdf.
Texto completoJodice, Patrick G. R. "Behavioral ecology of marbled murrelets (Brachyramphus marmoratus) in forest and marine ecosystems of Oregon". Connect to this title online, 1998. http://fresc.usgs.gov/products/thesis/jodice/thesis.html.
Texto completoAmadio, Carolina <1985>. "Numerical modelling of the benthic-pelagic coupling in coastal marine ecosystems at contrasting sites". Doctoral thesis, Università Ca' Foscari Venezia, 2019. http://hdl.handle.net/10579/17862.
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