Dissertations / Theses: 'Aquatic ecology'

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Leung, Roberto [UNESP]. "Distribuição de macrófitas aquáticas em relação a variáveis ambientais em ecossistemas lóticos da Bacia do rio Itanhaém." Universidade Estadual Paulista (UNESP), 2005. http://hdl.handle.net/11449/100647.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O objetivo deste trabalho foi estudar a distribuição das macrófitas aquáticas em rios da planície costeira da bacia do rio Itanhaém. A abordagem adotada foi uma combinação de estudos observacionais e experimentais. No primeiro capítulo, estudou-se a distribuição das macrófitas aquáticas em relação a variáveis ambientais da água e do sedimento em 97 km de rios em duas estações do ano (verão e inverno). A salinidade foi a principal variável ambiental responsável pela separação das macróf5tas aquáticas em duas comunidades distintas, a do estuário e a dos rios. As principais espécies que ocorreram no estuário foram Spartina alterniflora. Crinum procerum e Scirpus califhrnicus, sendo que a primeira ocorreu em trechos de maior salinidade, a segunda em trechos com salinidade intermediária e a última em trechos de menor salinidade. As espécies de água doce mais freqüentes foram Egeria densa, Eichhornia azurea, Eichhornia crassipes. Pistia stratiotes, e Salvínia molesta. Egeria densa tendeu a ocorrer em trechos com maior transparência. menor nitrogênio total e maior fração areia no sedimento. Eichhornia azurea tendeu a ocorrer em locais com alta transparência e baixas concentrações de nitrogénio total. Finja siratiotes tendeu a ocorrer em trechos de rios com maiores concentrações de nitrogênio total na água. A freqüência de ocorrência das principais espécies não diferiu entre o verão e o inverno, provavelmente devido a ausência de uma estação seca. No segundo capítulo, se estudou a ocorrência das macrófitas aquáticas em função da vegetação ciliar e da morfologia de canal em três trcchos distintos de rios. No estuário do rio ltanhaém. a ocorrência de macrófitas aquáticas emergentes foi correlacionada com o sombreamento das árvores de mangue e a declividadc da área litorânea... .
The aim of this research was to study the distribution of aquatic macrophytes in coastal piam rivers of ltanhaém basin. lhe research approach was based on observational and experimental studies. In the first chapter, the distribution of aquatic macrophyte was correlated to water and sediment environmental variables in 97 km of rivers and in two periods (summer and winter). Salinity was the most important environmental variable to separate the aquatie rnacrophytes in two distinct communities: estuarine and freshwater communities. The main species found in the estuary were Spartina alterniflora, Crinum procerum and Scirpus califohiicus. lhe first species was found in water with higher salinity, the second in water with intermediate salinity and the Iatter in less saline water. lhe most frequent &eshwater species were Egeria densa, Eichhornia azurea, Eichhornia crassipes, Pistia strarioles and Sal Wnia molesta. Egeria densa tended to be present in river sections with high water transparence. low total nitrogen, and high sand fraction in sediment. Eichhornia azurea tended to occur in sections with high water transparence and low total nitrogen. Pistia stratiotes tendecl to occur in river sections with high total nitrogen. lhe &equency of occurrence aquatic macrophyrtes did not significantly differed hetween sunimer and winter. due probably to the absence of a dry season. In the second chapter, we investigated the influence of riparian vegetation and stream channel morphology on aquatie rnacrophyte distribution in three streams with dstinguished landscape. In the estuary of ltanhaëm River, the occurrence of emergent rnacrophytes was correlated with mangrove shading and slope of littoral region. In Preto River... (Complete abstract, click electronic address below).

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Bruce, Louise Christina. "A study of the interaction between the physical and ecological processes of three aquatic ecosystems /." Connect to this title, 2005. http://theses.library.uwa.edu.au/adt-WU2007.0178.

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Silva, Carolina Vieira da [UNESP]. "Macroinvertebrados associados à macrófitas aquáticas flutuantes: distribuição, estrutura da comunidade e abordagem experimental." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/140219.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação do Instituto de Biociências (FUNDIBIO)
CAPES: 11152/13-6 BEX

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Christman, Van D. "Ecology of benthic macroinvertebrates in experimental ponds." Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-07282008-134927/.

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Blukacz, Edyta Agnes. "Error propagation in ecology, an aquatic example." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ58714.pdf.

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Hunt, Dana E. Ph D. Massachusetts Institute of Technology. "Aquatic microenvironments in bacterial ecology and diversity." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/43047.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2008.
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Includes bibliographical references.
Molecular surveys have revealed tremendous bacterial diversity in the world's oceans; yet how do these diverse bacteria with the same essential nutrient requirements co-exist in the same environment? This study examines the role of aquatic microenvironments in generating bacterial diversity: closely related organisms may co-exist in the same environment without competing for resources by a combination of habitat, metabolic, and behavioral differentiation. This hypothesis has been approached from several angles: (i) Within the bacterial family Vibrionaceae is there evidence for microenvironmental specialization or functional differentiation? (ii) Is there small scale clustering of bacteria around phytoplankton in the coastal ocean? Microdiverse clusters (< 1% 16S rRNA gene divergence) of Vibrionaceae were found to be differentially distributed between zooplankton-enriched, particulate, and planktonic water column microenvironments. However microhabitat preferences may not correspond to metabolic capabilities; chitin metabolism was observed to be a near ubiquitous metabolic characteristic of the Vibrionaceae, yet does not appear to be linked to colonization of chitinous zooplankton or particles. Finally, the microscale patchiness of bacterial cells was examined over an annual cycle, revealing seasonal variation and a positive correlation with eukaryotic cell number, suggesting that bacteria may cluster in the nutrient-rich microzones around algae in the environment. This study seeks to answer several fundamental questions about marine bacterial populations: how do closely related species co-exist in the same environment, do bacteria adapt to distinct microscale environments and how important are these microenvironments to bacterial productivity.
by Dana E. Hunt..
Ph.D.

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Lønborg, Christian. "Bioavailability of dissolved organic matter in coastal waters." Thesis, Available from the University of Aberdeen Library and Historic Collections Digital Resources, 2009. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?application=DIGITOOL-3&owner=resourcediscovery&custom_att_2=simple_viewer&pid=59094.

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Holland, Angela. "BRIDGING AQUATIC AND TERRESTRIAL ECOSYSTEMS: ECOLOGY OF SEMI-AQUATIC MAMMALS IN SOUTHERN ILLINOIS." OpenSIUC, 2016. https://opensiuc.lib.siu.edu/dissertations/1269.

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Mammals in freshwater aquatic systems play important roles as ecosystem engineers, trophic transfer agents, and apex predators, thus acting as indicators of freshwater ecosystem function. Watersheds inhabited by semi-aquatic mammals have increased links between adjacent terrestrial and aquatic ecosystems compared to watersheds where they are not present. Semi-aquatic mammals not only exert top-down influences on streams, but are affected by bottom-up forces from the riparian system itself. The goal of this study was to identify variables that correlate with the presence of beaver (Castor canadensis), muskrat (Ondatra zibethicus), mink (Neovison vison), and river otter (Lontra canadensis), including their interactions, resulting in a better understanding of the areas where these semi-aquatic mammals occur and their effects on the riparian system. The objectives of this study were (1) to identify variables related to the probability of detection, initial occupancy, colonization, and extinction of the 4 semi-aquatic mammals in southern Illinois; and (2) to test if the reintroduction of river otter has changed stream food webs. To address my first objective, I sampled 120 bridge sites in 2 periods (winter: Jan-Feb; and spring: Mar-Apr) during 2012–2014 in 11 major watersheds in the southern third of Illinois (44,526 km2) to estimate multi-season occupancy. Each survey unit was a 400-m stream segment visited twice by 2 observers for a total of 4 observations per site per period. Observers recorded all mammal signs found, including sign species and type. Sites were Intensive Basin Survey Sites sampled by Illinois Department of Natural Resources (IDNR) and Illinois Environmental Protection Agency (IEPA), allowing data collected by the state to be available for explanatory variables for mammal occupancy. Data collected by the Illinois Natural History Survey (INHS) also were available for a subset of sites. I collected local- and landscape-scale habitat and weather variables for each site. I developed hypotheses regarding occupancy of sites based on land-cover, human disturbance, and stream attributes for each species. I developed additional hypotheses regarding prey availability and water quality for river otter and mink. Sites used in each analysis were dependent on data available to address the hypotheses of interest. Beaver and muskrat were present at ≥100 of 103 sites for ≥1 observation. Naïve occupancy was high (≥82%) every year for both species. Detection probabilities for beaver and muskrat were best predicted by survey period. Beaver detection remained fairly constant across survey periods except for a decrease in winter 2014, whereas muskrat detection was generally lower during winter and higher during spring. Beaver were more likely to occupy larger streams than smaller streams during the initial survey period. Sites that lacked a dominant land-cover had a lower probability of beaver colonization than sites dominated by agriculture or woody vegetation at the landscape scale. In addition, the probability that a site would be colonized by beaver during the study increased with availability of water within 1 km of the surveyed segment, increased stream density, sites at larger streams, and river otter presence during the previous period. The probability of site extinction decreased as stream size, stream density within 1 km, and water availability within 500 m of the survey segment increased. Occupancy of muskrat during the initial survey period was negatively predicted by % forest in the 1-km riparian area, channel incision, and amount mercury in the sediment. Colonization by muskrats was lower during the long spring to winter intervals than the short winter to spring intervals, and was positively related to the amount of organic carbon in the sediment. The probability of site extinction by muskrat increased with increasing % forest within the riparian area around the stream segment, decreasing 1-km stream density, and when land-cover within 1 km of sites was dominated by agriculture or woody vegetation. Multi-season occupancy of river otter and mink were assessed in 2 separate analyses that used either land-cover and management variables or prey availability and riparian community composition, respectively. In the first analysis, river otter and mink were present at ≥84 of 103 sites. Naïve occupancy was higher every year for mink (≥88.3%) than for river otter (≥55.3%). Detection of river otter and mink in the first analysis increased as substrate availability increased. Occupancy of river otter during the initial survey period was predicted by large stream size, low % developed area within 250 m of the surveyed segment, and proximity to nearest river otter reintroduction point. Probability of colonization by river otter varied by survey period and was higher at sites with larger streams, higher stream density, lower % developed area, and within a known river otter population area. Site extinction by river otter in the first analysis varied by survey period and was linked to increased organic carbon in the sediment, and decreased road density within 1 km of the surveyed segment. River otter harvest was not found to affect site colonization or extinction. Mink occupancy during the initial period was negatively associated with water availability within 100 m of the survey segment. Site colonization by mink varied by month and increased with increasing developed area within 100 m of the surveyed segment, increasing channel incision, and decreasing rainfall. Probability of site extinction for mink increased as stream size and developed area within 500 m of the surveyed segment increased, and when woody vegetation was the dominant land-cover type within 1 km of the surveyed segment. The second analysis of multi-season occupancy of river otter and mink used 77 sites, 81.8% of which had ≥1 river otter detection in the study and 98.7% of which had ≥1 mink detection. Naïve occupancy differed between years but gradually increased for river otter and remained high (≥93.5%) for mink. Increasing substrate availability increased the probability of river otter detection, whereas mink detection varied by survey period. Occupancy during the initial survey period was higher in sites closer to the reintroduction points for river otter. Probability of colonization of river otter was positively associated with macroinvertebrate IBI and fish species richness, sites with high fish species richness of fish families preferred by river otter also had reduced otter extinction probability. No tested variables predicted initial occupancy for mink, but mink were more likely to colonize sites with increased fish richness and when muskrat were present during the previous period. Mink had decreased probability of extinction in sites with increasing mussel community index. My results indicate that semi-aquatic mammals in Illinois were affected by a riparian habitat, water availability, and stream community variables at both the landscape and local scale. I found high occupancy of mink, beaver, and muskrat across the entire landscape of southern Illinois, and my results suggest that the geographic range of river otter continues to expand. Relationships of occupancy of these semi-aquatic mammals to measurements of urban areas and human disturbance were not consistent across all species. Mink and river otter occupancy were both predicted by aspects of prey availability, indicating the importance of predator-prey relationships in occupancy dynamics of riparian predators. Hypotheses regarding predator pressure and changes in environmental variables were used to test the effects of river otter reintroduction on stream communities. For this objective, I used structural equation models. I compared fish and macroinvertebrate communities from before (1982-1995) and after (2005-2013) reintroduction of river otter, which occurred in 1994–1996. Fish and macroinvertebrate community data for 35 sites located throughout 6 major watersheds in southern Illinois (25,550 km2) were obtained from state agencies. Changes in stream communities were evaluated using 4 metrics (species richness, species dominance, skewness in size distribution of prey, and proportion of individuals in the size class preferred by river otter). Neither the inclusion of river otter site use nor change in stream quality, measured by change in % forest, improved models over the simple model which only included fish and macroinvertebrate communities. Overall, I found no evidence that river otter presence or change in forest cover affected stream fish and macroinvertebrate communities.

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She, Nian. "Chaos in aquatic systems /." Thesis, Connect to this title online; UW restricted, 1995. http://hdl.handle.net/1773/6370.

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Church, Kathleen. "Agonistic interactions between invasive aquatic species." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=86980.

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Species invasions threaten the integrity of biotic communities, as invaders may outcompete and replace resident species. For many aquatic invaders, species replacements are driven by aggression. I explored this phenomenon through a quantitative synthesis and laboratory experiments. A quantitative synthesis of published studies on aggression in aquatic invaders found that body size and prior residency generally mediate the outcome of aggressive encounters, but there is no consistent tradeoff between intra- and interspecific aggression. As the majority of studies on agonistic interactions focus on phylogenetically related species, I investigated such interactions between two unrelated invasive species that occupy a similar niche: the round goby (Neogobius melanostomus) and the spinycheek crayfish (Orconectes limosus), both benthic omnivores that compete for shelter. Laboratory experiments revealed that round gobies were more aggressive than crayfish, regardless of prior residency. Heightened aggression may be a selective advantage for an animal to invade a habitat occupied by another territorial species.
Les invasions d'espèces posent une menace à l'intégrité des communautés biologiques, puisque les espèces envahissantes peuvent gagner la compétition contre les espèces résidentes et en conséquence les supplanter. Le remplacement par des espèces envahissantes est souvent dû à leur comportement agressif. J'ai étudié ce phénomène en employant des méthodes de méta analyse et des expériences en laboratoire. Une méta analyse sur les actes d'agression chez les espèces envahissantes a démontré que la taille du corps et le statut de résidence antérieure affectent généralement le résultat des affrontements, mais il n'y a pas de compromis entre les actes d'agression intra et interspécifique. Puisque la plupart des études sur les interactions agonistes se concentrent sur des espèces apparentées taxonomiquement, j'ai examiné une telle interaction entre deux espèces envahissantes éloignées taxonomiquement qui occupent une niche semblable : le gobie à taches noires (Neogobius melanostomus) et l'écrevisse américaine (Orconectes limosus), deux omnivores qui se font compétition pour leur refuge. Les expériences en laboratoire ont démontré que les gobies à taches noires étaient plus agressifs que les écrevisses, indépendamment du statut de résidence antérieure. Le comportement agressif accru peut être un avantage sélectif qui permet à un animal d'envahir un habitat occupé par une autre espèce territoriale.

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Butler, C. "Pesticide induced stresses in aquatic bacteria." Thesis, Cardiff University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374732.

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Hanford, Jayne Kathryn. "Aquatic Biodiversity and Mosquito Ecology in Urban Wetlands." Thesis, University of Sydney, 2020. https://hdl.handle.net/2123/23225.

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Global wetland loss means urban wetlands are an increasingly valuable conservation resource. Concerns around mosquito-borne diseases will restrict how we manage these wetlands for conservation, yet the impacts of common wetland management practices on aquatic biodiversity and mosquitoes are often untested, and our understanding of interactions between biodiversity, mosquitoes and wetland and landscape traits is severely limited. I used a combination of observational and landscape scale manipulative field experiments and laboratory experiments to characterise relationships between aquatic biodiversity, mosquitoes, wetland traits, surrounding human population density, invasive species and wetland management regimes. I found that aquatic biodiversity and abundance of mosquito species of pest and public health importance respond to wetland design traits and human population density, though biodiversity and mosquitoes are not necessarily responding to each other. Wetland management regimes and the presence of invasive species can significantly affect aquatic biodiversity and mosquito abundance, as well as mosquito behaviour. Direct and indirect relationships between mosquitoes and other aquatic biota appear to influence subsequent community recovery following such disturbances. Relationships altered due to wetland management regimes and the presence of invasive species in turn have the potential to shape mosquito risks associated with freshwater urban wetlands and influence the value of these wetlands to urban biodiversity. To maximise the ecological benefits of the growing number of freshwater urban wetlands without creating perverse impacts on public health and wellbeing associated with mosquito exposure requires not only improved integration between the traditionally separate fields of wetland ecology and medical entomology, but also consideration of species-specific responses and design traits to pre-emptively minimise potential risks.

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Vander, Zanden M. Jake. "Trophic position in aquatic food webs." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ55390.pdf.

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Bush, Simon R. "A political ecology of living aquatic resources in Lao PDR." Thesis, The University of Sydney, 2004. http://hdl.handle.net/2123/975.

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This thesis uses a political ecology framework to critically analyse how development and environmental orthodoxies influence the use, management and development of living aquatic resources in an information poor developing country context. The research focuses specifically on Lao PDR, the only landlocked country of the Mekong River Basin, to question how knowledge over living aquatic resources is framed by a range of stakeholders. Specific attention is given to how aquaculture has gained ascendancy over capture fisheries in the rhetoric of resources users as well as government and nongovernment organisations. The empirical research focuses on the role of broad scale economic, social and environmental influences over resource use, the practical and perceived importance of both aquaculture and capture fisheries in rural Lao livelihoods and finally, how living aquatic resources are represented within the dominant development agendas of conservation, poverty alleviation and rural development. Field work was conducted in Savannakhet province in Southern Lao PDR over 18 months from 2001 to 2002. The thesis has a strong empirical research base divided into activities carried out over multiple scales ranging from household to the Mekong River Basin. The thesis begins by establishing the historical context of resource use as well as the major orthodoxies on which development is based. Attention then turns to the extensive empirical research conducted over three districts of Savannakhet province. The results of the empirical research report two macro scale studies at the district level. The first is a survey of fish ponds across three districts focusing on the spatial distribution of investment and resource use. The second is a survey of fish trade focusing on the differential trade between culture and capture fish species. The results of both studies highlight the disjuncture between complex patterns of aquaculture and capture fishery use and the major assumptions made about the use of these two resources by policy makers and management. Analysis then moves to the local level focusing on the role and importance of aquaculture and capture fisheries to the livelihoods of rural Lao communities. The results show the instrumental and hermeneutic importance of fish and other aquatic resources in the livelihoods of households and the community. In particular it is shown that capture fisheries are more important to rural livelihoods in terms of income and nutrition, while aquaculture is perceived as a more important activity in the development of community and household economies. ii The final section then compares the empirical findings of the thesis with the policy and planning agendas of government and non-government organisations. The analysis focuses on the role of ideas and agency creating a highly politicised policy environment concluding that aquaculture based policy is more compatible with both government and non government agendas of poverty alleviation and rural development than capture fisheries. Furthermore, capture fisheries are marginalised within conservation as a resource that cannot contribute to the improvement of livelihoods or alleviate poverty. The thesis concludes that living aquatic resources provide an imperative source of food and income to rural communities through diverse and complex human-environment interactions. In contrast government and non-government organisations operating at regional, national and local scales of policy and planning simplify these relationships drawing on wider orthodoxies of aquaculture and capture fisheries development. These simplifications do not reflect the problems and needs of the predominantly rural population. Furthermore, in the absence of a strong empirical base of information, living aquatic resources management and development has become highly politicised. Instead of responding to the realities of resource users, policy and planning reflect the interests and beliefs of development organisations, government and non-government. The thesis provides an important, grounded account of the importance of living aquatic resources to rural livelihoods in Lao PDR and how these resources are understood and translated into national development and management agendas. In doing so the thesis contributes to an understanding of how complex human-environmental systems are perceived and represented in development policy and wider knowledge systems. The thesis also makes an important theoretical contribution to the growing body of literature on critical political ecology by arguing for the revitalisation of ecology as an integrated approach within political ecology and more widely within the study of humanenvironment interaction.

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Bush, Simon R. "A political ecology of living aquatic resources in Lao PDR." University of Sydney, 2004. http://hdl.handle.net/2123/975.

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Doctor of Philosophy(PhD)
This thesis uses a political ecology framework to critically analyse how development and environmental orthodoxies influence the use, management and development of living aquatic resources in an information poor developing country context. The research focuses specifically on Lao PDR, the only landlocked country of the Mekong River Basin, to question how knowledge over living aquatic resources is framed by a range of stakeholders. Specific attention is given to how aquaculture has gained ascendancy over capture fisheries in the rhetoric of resources users as well as government and nongovernment organisations. The empirical research focuses on the role of broad scale economic, social and environmental influences over resource use, the practical and perceived importance of both aquaculture and capture fisheries in rural Lao livelihoods and finally, how living aquatic resources are represented within the dominant development agendas of conservation, poverty alleviation and rural development. Field work was conducted in Savannakhet province in Southern Lao PDR over 18 months from 2001 to 2002. The thesis has a strong empirical research base divided into activities carried out over multiple scales ranging from household to the Mekong River Basin. The thesis begins by establishing the historical context of resource use as well as the major orthodoxies on which development is based. Attention then turns to the extensive empirical research conducted over three districts of Savannakhet province. The results of the empirical research report two macro scale studies at the district level. The first is a survey of fish ponds across three districts focusing on the spatial distribution of investment and resource use. The second is a survey of fish trade focusing on the differential trade between culture and capture fish species. The results of both studies highlight the disjuncture between complex patterns of aquaculture and capture fishery use and the major assumptions made about the use of these two resources by policy makers and management. Analysis then moves to the local level focusing on the role and importance of aquaculture and capture fisheries to the livelihoods of rural Lao communities. The results show the instrumental and hermeneutic importance of fish and other aquatic resources in the livelihoods of households and the community. In particular it is shown that capture fisheries are more important to rural livelihoods in terms of income and nutrition, while aquaculture is perceived as a more important activity in the development of community and household economies. ii The final section then compares the empirical findings of the thesis with the policy and planning agendas of government and non-government organisations. The analysis focuses on the role of ideas and agency creating a highly politicised policy environment concluding that aquaculture based policy is more compatible with both government and non government agendas of poverty alleviation and rural development than capture fisheries. Furthermore, capture fisheries are marginalised within conservation as a resource that cannot contribute to the improvement of livelihoods or alleviate poverty. The thesis concludes that living aquatic resources provide an imperative source of food and income to rural communities through diverse and complex human-environment interactions. In contrast government and non-government organisations operating at regional, national and local scales of policy and planning simplify these relationships drawing on wider orthodoxies of aquaculture and capture fisheries development. These simplifications do not reflect the problems and needs of the predominantly rural population. Furthermore, in the absence of a strong empirical base of information, living aquatic resources management and development has become highly politicised. Instead of responding to the realities of resource users, policy and planning reflect the interests and beliefs of development organisations, government and non-government. The thesis provides an important, grounded account of the importance of living aquatic resources to rural livelihoods in Lao PDR and how these resources are understood and translated into national development and management agendas. In doing so the thesis contributes to an understanding of how complex human-environmental systems are perceived and represented in development policy and wider knowledge systems. The thesis also makes an important theoretical contribution to the growing body of literature on critical political ecology by arguing for the revitalisation of ecology as an integrated approach within political ecology and more widely within the study of humanenvironment interaction.

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Leung, Roberto. "Distribuição de macrófitas aquáticas em relação a variáveis ambientais em ecossistemas lóticos da Bacia do rio Itanhaém /." Rio Claro : [s.n.], 2005. http://hdl.handle.net/11449/100647.

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Orientador: Antonio Fernando Monteiro Camargo
Banca: Massanori Takaki
Banca: Raoul Henry
Banca: Denise de Campos Bicudo
Banca: Marcelo L.M. Pompêo
Resumo: O objetivo deste trabalho foi estudar a distribuição das macrófitas aquáticas em rios da planície costeira da bacia do rio Itanhaém. A abordagem adotada foi uma combinação de estudos observacionais e experimentais. No primeiro capítulo, estudou-se a distribuição das macrófitas aquáticas em relação a variáveis ambientais da água e do sedimento em 97 km de rios em duas estações do ano (verão e inverno). A salinidade foi a principal variável ambiental responsável pela separação das macróf5tas aquáticas em duas comunidades distintas, a do estuário e a dos rios. As principais espécies que ocorreram no estuário foram Spartina alterniflora. Crinum procerum e Scirpus califhrnicus, sendo que a primeira ocorreu em trechos de maior salinidade, a segunda em trechos com salinidade intermediária e a última em trechos de menor salinidade. As espécies de água doce mais freqüentes foram Egeria densa, Eichhornia azurea, Eichhornia crassipes. Pistia stratiotes, e Salvínia molesta. Egeria densa tendeu a ocorrer em trechos com maior transparência. menor nitrogênio total e maior fração areia no sedimento. Eichhornia azurea tendeu a ocorrer em locais com alta transparência e baixas concentrações de nitrogénio total. Finja siratiotes tendeu a ocorrer em trechos de rios com maiores concentrações de nitrogênio total na água. A freqüência de ocorrência das principais espécies não diferiu entre o verão e o inverno, provavelmente devido a ausência de uma estação seca. No segundo capítulo, se estudou a ocorrência das macrófitas aquáticas em função da vegetação ciliar e da morfologia de canal em três trcchos distintos de rios. No estuário do rio ltanhaém. a ocorrência de macrófitas aquáticas emergentes foi correlacionada com o sombreamento das árvores de mangue e a declividadc da área litorânea... (Resumo completo, clicar acesso eletrônico abaixo).
Abstract: The aim of this research was to study the distribution of aquatic macrophytes in coastal piam rivers of ltanhaém basin. lhe research approach was based on observational and experimental studies. In the first chapter, the distribution of aquatic macrophyte was correlated to water and sediment environmental variables in 97 km of rivers and in two periods (summer and winter). Salinity was the most important environmental variable to separate the aquatie rnacrophytes in two distinct communities: estuarine and freshwater communities. The main species found in the estuary were Spartina alterniflora, Crinum procerum and Scirpus califohiicus. lhe first species was found in water with higher salinity, the second in water with intermediate salinity and the Iatter in less saline water. lhe most frequent &eshwater species were Egeria densa, Eichhornia azurea, Eichhornia crassipes, Pistia strarioles and Sal Wnia molesta. Egeria densa tended to be present in river sections with high water transparence. low total nitrogen, and high sand fraction in sediment. Eichhornia azurea tended to occur in sections with high water transparence and low total nitrogen. Pistia stratiotes tendecl to occur in river sections with high total nitrogen. lhe &equency of occurrence aquatic macrophyrtes did not significantly differed hetween sunimer and winter. due probably to the absence of a dry season. In the second chapter, we investigated the influence of riparian vegetation and stream channel morphology on aquatie rnacrophyte distribution in three streams with dstinguished landscape. In the estuary of ltanhaëm River, the occurrence of emergent rnacrophytes was correlated with mangrove shading and slope of littoral region. In Preto River... (Complete abstract, click electronic address below).
Doutor

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17

Ward, Jessica MacKay. "Community-level effects of nonindigenous aquatic ecosystem engineers." Thesis, McGill University, 2010. http://digitool.Library.McGill.CA:8881/R/?func=dbin-jump-full&object_id=92244.

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18

Painter, Duncan John. "Fen ditch excavation patterns : effects on aquatic communities." Thesis, University of Cambridge, 1996. https://www.repository.cam.ac.uk/handle/1810/283706.

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19

Villastrigo, Carbajo Adrián. "Macroevolutionary patterns of habitat transitions in aquatic Coleoptera." Doctoral thesis, Universitat de Barcelona, 2019. http://hdl.handle.net/10803/668249.

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Understanding the evolutionary processes underlying extant biodiversity may help us to comprehend why species richness is not equally distributed between clades. One of the main causes to explain the disparity of species richness is the development of key innovations in particular clades, increasing or decreasing their capabilities to occupy new environments, to exploit novel resources or to cope with competition. The present thesis focuses on explaining the macroevolutionary consequences of two of the most common habitat transitions in aquatic environments: between environments with different degree of salinity, and between running and standing waters. Among inhabitants of aquatic environments aquatic Coleoptera are one of the most diverse, with representatives living in all kind of environments, including both running and standing waters and, not infrequently, saline environments. The most speciose aquatic Coleoptera families living in aquatic habitats are Hydrophilidae, Dytiscidae and Hydraenidae, but only the evolution of the ecological transitions of the former have been previously studied under a phylogenetic perspective. In this thesis, we assessed the evolutionary patterns of selected tribes belonging to the other two families. Despite aquatic Coleoptera being a relatively well-studied fauna, we needed to address several systematic modifications that revealed the true evolutionary history of the studied groups, describing a genus and three subgenera of Hygrotini, plus other modifications of both Hygrotini and Ochthebiini taxonomy (Chapters 1 and 3), setting the basis of this thesis. Transitions between environments with different degree of saline waters was addressed for Hygrotini (Dytiscidae family, Chapter 2) and Ochthebiini (Hydraenidae family, Chapter 5). We detected multiple origins of tolerance to saline waters, with a gradual acquisition in almost all cases and only direct transitions to hypersaline waters in fairly isolated clades, mostly associated with coastal rockpools. Moreover, tolerance to hypersaline waters was found to be irreversible, but it did not follow an evolutionary dead-end pattern as lineages exhibiting this trait still maintain their diversification capabilities (as seen in Cobalius subgenus, Chapter 5). Additionally, our results seem to link the origin of lineages exhibiting tolerance to saline waters to periods of global aridification, in accordance with previous studies in Hydrophilidae. Transitions between running and standing waters were studied in Hydroporini (Dytiscidae family, Chapter 6). We unveiled that species living in lotic and lentic habitats display similar diversification patterns, but the habitat preference is affecting the body size of the species, with reduced body sizes in specialized environments (i.e. smaller species in running waters). Finally, the field sampling in saline habitats led to the discovery of a new species for science, described as Ochthebius (Micragasma) minoicus (Chapter 4).
Estudiar los procesos evolutivos que ocasionan la biodiversidad actual puede ayudarnos a comprender mejor como la riqueza de especies está distribuida de forma desigual en diferentes clados. Una de las causas principales para explicar este fenómeno es el desarrollo de innovaciones clave que modifican las capacidades de las especies para sobrevivir en nuevos ambientes, acceder a nuevos recursos, o para lidiar la competencia con otras especies. Esta tesis se focaliza en explicar las consecuencias macroevolutivas de dos de las transiciones de hábitat más comunes en ecosistemas acuáticos: aquellas entre ecosistemas con diferente nivel de salinidad, y aquellas entre ecosistemas de aguas corrientes y aguas estancas. Entre los habitantes de ambientes acuáticos, los escarabajos son uno de los grupos más diversos, con especies capaces de vivir en todo tipo de ambientes, incluyendo aguas corrientes y estancas, y en ocasiones, ambientes salinos. Las familias más diversas de escarabajos acuáticos son Hydrophilidae, Dytiscidae e Hydraenidae, aunque solo la primera ha sido estudiada desde una perspectiva evolutiva. En esta tesis, evaluamos los patrones evolutivos de varias tribus pertenecientes a las otras 2 familias. A pesar de que los escarabajos acuáticos son un grupo bien estudiado en general, ha sido necesario realizar modificaciones en la clasificación de algunos grupos para reflejar su verdadera historia evolutiva, describiendo un nuevo género y tres subgéneros para la tribu Hygrotini. Adicionalmente, se han realizado pequeñas modificaciones tanto en Hygrotini como en Ochthebiini, siendo la base sobre la que se han desarrollado los posteriores estudios filogenéticos de esta tesis. Las transiciones entre ambientes con diferente nivel de salinidad han sido estudiadas para Hygrotini (familia Dytiscidae, Capítulo 2) y Ochthebiini (familia Hydraenidae, Capítulo 5). Se han detectado múltiples orígenes de la tolerancia a la salinidad, adquiriéndose esta característica de forma gradual en la mayoría de los casos. Los casos en los que se han descubierto transiciones directas de ambientes de agua dulce hacia ambientes hipersalinos, son clados aislados en la filogenia y asociados con ambientes de charcas costeros. Además, la tolerancia de aguas hipersalinas ha demostrado ser una característica irreversible, aunque no por ello se trata de un dead-end evolutivo (callejón sin salida), ya que las especies que viven en estos ambientes conservan su capacidad de diversificación, llegando incluso a ser superior a la de otras especies (por ejemplo, el subgénero Cobalius, Capítulo 5). A si mismo, nuestros resultados relacionan el origen de linajes tolerantes a la salinidad con periodos de aridificación a escala global, un patrón que confirma el encontrado en la familia Hydrophilidae. En cuanto a las transiciones entre aguas corrientes y estancas estudiada en Hydroporini (familia Dytiscidae, Capítulo 6), hemos encontrado patrones similares en las especies que viven en ambos ambientes, aunque los análisis sugieren la posibilidad de una mayor tasa de diversificación en ambientes de aguas estancadas. Nuestros resultados han destacado una correlación entre la preferencia del hábitat de las especies con su tamaño corporal, de manera que las especies que se encuentran en ambientes más especializados (en aguas corrientes) son aquellas con menor tamaño. Adicionalmente, se ha demostrado que la transición entre ambientes no es per se un factor que afecta al tamaño corporal de las tesis. Finalmente, gracias a los numerosos trabajos de campo realizados enfocados en los ambientes salinos, se ha podido describir la especie Ochthebius (Micragasma) minoicus (Capítulo 4).

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20

Blanco, Camila Gastaldi [UNESP]. "Macrofauna associada aos bancos de mexilhão Perna perna: padrões naturais, pressão de predação e o efeito da pesca." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/111043.

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Os bancos de mexilhões são conhecidos engenheiros de ecossistema que agregam uma diversificada fauna associada. A exploração antrópica dos mexilhões pode alterar a estrutura e distribuição desses bancos e consequentemente influenciar a composição da fauna associada. Para testar a influencia da pesca sobre os mexilhões e sua fauna associada utilizamos da técnica do quadrado (15X15 cm, n=8) raspando bancos com mexilhões em um de três estágios de desenvolvimento (recrutas, juvenis, adultos). A fauna associada foi separada dos mexilhões, identificada e quantificada (abundancia, biomassa, riqueza e diversidade). Os mexilhões foram mensurados em relação à tamanho, peso, e volume (total e intersticial). Amostras de mexilhões obtidas diretamente de pescadores das mesmas praias de estudo foram analisadas quantos aos mesmos parâmetros, para posterior comparação por análises estatísticas descritivas (ANOVA) e multivariadas exploratórias (nMDS e PERMANOVA). Observou-se a presença de bancos diferenciados, com mexilhões de um mesmo tamanho e com valores de fauna correspondente. Sendo, a presença dos pescadores pode influenciar a distribuição e composição dos bancos de mexilhões, afetando no seu recrutamento e consequentemente pode afetar a fauna associada a esses bancos

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21

Migliorini, Gustavo Henrique [UNESP]. "Efeitos da diversidade funcional de detritos sobre a estrutura de comunidades e o funcionamento de ecossistemas de fitotelmatas." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/122140.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Entender os efeitos da biodiversidade sobre as comunidades e processos ecossistêmicos é fundamental diante das crescentes taxas de extinções e alterações nos ecossistemas naturais. A diversidade pode influenciar o consumo de recursos que regem processos ecossistêmicos através de dois mecanismos principais: (i) propriedades complementares de espécies incluindo partição de nicho e facilitação e (ii) fortes efeitos de espécies dominantes sobre a função de interesse (efeito de seleção). Detritos de matéria orgânica (e.g. folhas mortas) representam a base da produção primária em muitos ecossistemas. Os atributos funcionais dos detritos podem alterar o ambiente e influenciar a composição e a estruturação da comunidade associada, bem como o funcionamento ecossistêmico. Assim, investigamos se a diversidade de detritos afeta a colonização, a sobrevivência de insetos detritívoros e o processamento de detritos em fitotelmatas da bromélia Quesnelia arvensis. Manipulamos a diversidade de detritos em bromélias e avaliamos o impacto da identidade e atributos funcionais desses detritos sobre a comunidade de invertebrados aquáticos (colonização e sobrevivência) e em um processo ecossistêmico chave, a decomposição. A composição de colonizadores foi afetada pela diversidade de detritos. Esses resultados indicam que a disponibilidade de fontes diversas de recursos variados fornecem mais oportunidades aos detritívoros aquáticos e terrestres para aperfeiçoar a aquisição de nutrientes e se estabelecer no sistema. Os maiores níveis de sobrevivência dos Chironomidae foram detectados em duas monoculturas (espécies individuais dos detritos) e na policultura (mistura das espécies de detritos); ainda, a sobrevivência na policultura foi maior que a média das monoculturas. Estes resultados indicam haver, na policultura, um efeito de seleção positiva para Chironomidae. Outros detritívoros (Scirtidae e Trichoptera) ...
Understanding the biodiversity effects on community and ecosystem processes is crucial in the face of growing extinction rates and shifts in natural ecosystems. Diversity can influence the consumption of resources governing ecosystem processes through two main mechanisms: (i) complementary properties of species, including niche partitioning and facilitation and (ii) strong dominant species effects on the function of interest (selection effect). Detritus of organic matter (e.g. dead leaves) are the base of primary production in many ecosystems. Detritus functional traits may alter the environment and influence the composition and structure of the associated community, as well as ecosystem functioning. Thus, we investigated if detritus diversity affects the 20 colonization and survival of detritivorous aquatic insects and the detritus processing in phytotelmata of tank bromeliads (Quesnelia arvensis). We manipulated the leaf litter diversity in bromeliads and evaluated the effects on the aquatic invertebrate community (colonization and survival) and a key ecosystem process, decomposition. The higher values of Chironomidae survival were detected for the polyculture (mixed leaf species) and two monocultures (single leaf species); also, the effect of polyculture is greater than the mean of the monocultures. These results indicate a positive selection effect for Chironomidae. Other detritivores (Scirtidae and Trichoptera) were not affected by detritus diversity. Contrary to prediction, decomposition rate was not affected by leaf detritus diversity. This can be explained by the fact that two of three detritivores were not affected in the survival. These two (Scirtidae and Trichoptera) must have, by complementarity, occupied the Chironomidae niche for the detritus consumption. The composition of aquatic and terrestrial colonizing arthropods was affected by detritus diversity. These results indicate that the availability of different resources ...
FAPESP: 2012/20249-0

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22

Piccoli, Gustavo Cauê de Oliveira [UNESP]. "Um predador generalista na fronteira entre ecossistemas: interações tróficas e os processos ecossitêmicos bromelícolas." Universidade Estadual Paulista (UNESP), 2015. http://hdl.handle.net/11449/138495.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A predação é uma interação entre espécies com forte impacto na estrutura e dinâmica dos ecossistemas, não só em ambientes aquáticos e terrestres, mas também de forma conectiva em ecótonos onde a fronteira entre eles é tênue. O microcosmo natural misto contido em bromélias tanque, ou seja, formado por componentes terrestres e aquáticos, é um sistema favorável para estudos sobre os efeitos interecossistêmicos da predação e seus reflexos sobre os processos ecossistêmicos bromelícolas. Nesta Tese busquei por meio de observações e experimentos em campo elucidar questões comportamentais e ecológicas de um predador terrestre, a aranha Corinna demersa (Corinnidae) e sua relação com os organismos aquáticos e processos ecossistêmicos contido nos fitotelmatas de bromélias tanque em uma área de Mata Atlântica no litoral sudeste brasileiro. No primeiro capítulo, reconheci a interação exclusiva deste predador com bromélias tanque, habitat o qual ele utiliza durante todo seu ciclo de vida com comportamentos adaptados a este ambiente. No segundo capítulo, identifiquei os efeitos diretos e indiretos deste predador terrestre em uma comunidade aquática simplificada e comparei a intensidade da cascata trófica causada por ele, pelo predador aquático e por ambos. Os principais resultados foram os efeitos letais diferenciados do predador terrestre e aquático entre os grupos de detritívoros e a interação antagonística entre eles refletida na sobrevivência total das presas aquáticas. Reconheci a influência da qualidade dos detritos sobre a intensidade das cascatas tróficas desencadeadas pelos predadores sobre a fragmentação de detritos. A cascata ocasionada pelo predador aquático pode ser mais intensa que a ocasionada pelo predador terrestre em determinado tipo de detrito, porém também é amortecida ou intensificada pelo efeito interativo dos predadores sobre os detritívoros. No último capítulo, testei o efeito...
Predation is a kind of ecological interaction that strongly influences the structure and dynamic of not only terrestrial and aquatic ecosystems, but also in a connective way in the ecotones where the borders lines are thin. Tank bromeliads provide a naturally mixed microcosm, composed by both terrestrial and aquatic elements, being suitable for the study of across-ecosystems predation effects, and the consequences in the bromeliad ecosystem effects. In our study we aimed to elucidated behavioral and ecological issues of the terrestrial predator, the spider Corinna demersa (Corinnidae), and its relationship with aquatic organisms and the ecosystem processes present in the tank bromeliads of the Atlantic Rainforest in the southeastern coast of Brazil. In the first chapter we identify the exclusive interaction between this predator and tank bromeliads, being the habitat where the spider spends its whole life, showing particular behaviors adapted to this environment. In the second chapter the direct and indirect effects of this predator in an aquatic and simplified community were identified, being the intensity of the trophic cascade compared when initiated by the terrestrial predator, by the aquatic and both. The main results point out the distinct lethal effects between terrestrial and aquatic predators and their antagonistic interaction, which results in the total survivor of aquatic preys. We documented the influence of the quality of detritus on the intensity of trophic cascades triggered by predators over the fragmentation rate of detritus. A cascade generated by the aquatic predator may be more intense than that generated by the terrestrial predator in a specific type of detritus, although it could be either diminished or enhanced due to the interactive effect of predators over detritivorous. In the last part, we verified the effect of the food availability by the presence of a terrestrial prey, on the interaction between C. demersa ...

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23

Hudson, Traci D. "Developing methods for the rapid molecular assessment of aquatic microbial communities." Huntington, WV : [Marshall University Libraries], 2003. http://www.marshall.edu/etd/descript.asp?ref=446.

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Thesis (M.S.)--Marshall University, 2003.
Title from document title page. Includes abstract. Document formatted into pages; contains ix, 111 including illustrations. Includes bibliographical references (p. 49-71).

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24

Mizner, Jack H. "The secondary production dynamics of simulium taxodium and simulium lakei (diptera: simuliidae) in the Ogeechee River, Georgia." Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/25222.

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25

Lowcock, Diane. "The survival of Aeromonas hydrophila in aquatic systems." Thesis, University of Liverpool, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385300.

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26

Lu, Xinxin. "Microbially Mediated Transformation of Dissolved Nitrogen in Aquatic Environments." Kent State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=kent1429540424.

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27

Bruce, Louise Christina. "A study of the interaction between the physical and ecological processes of three aquatic ecosystems." University of Western Australia. Centre for Water Research, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0178.

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Due to the complex nature of aquatic food webs, the interaction between abiotic and biotic factors that govern ecosystem dynamics is often elusive. Recent advancements in both the collection of reliable field data and the development of ecological models have enabled researchers to gain insights into these more complex interactions. In this study the relationship between physical and ecological processes has been explored by applying a process based coupled physical and ecological model (DYRESM-CAEDYM) to the data sets of three aquatic ecosystems. In the first, the role of zooplankton in the nutrient cycles of Lake Kinneret, Israel was quantified. The model was parameterized and calibrated using an extensive field data set. It was found that the excretion of dissolved nutrients by zooplankton accounted for up to 58% of phytoplankton demand and that this value varied seasonally in response to patterns of stratification and mixing. In the second ecosystem, Mono Lake, USA, results from model simulations were studied to determine the significance of the transport of nutrient rich hypolimnetic water via the benthic boundary layer (BBL) on lake productivity. Model results indicated that although on average the impact of BBL transport on Mono Lake ecology was not large, significant nutrient fluxes were simulated during periods when BBL transport was most active. The timing of these fluxes in the context of seasonal changes were found to be critical to specific aspects of food web dynamics. In the final application, the ecological gradients of the primary salt ponds of Shark Bay, Australia were studied with specific focus on the role of zooplankton as a determinant of ecosystem dynamics. Model results indicated that zooplankton grazing was responsible for reduced water column particulate organic matter and increased light available for the development of microbial mats. However, no direct 8 link between zooplankton grazing and observed changes in planktonic algal species composition or nutrient limitation across the salinity gradient of the ponds was found. Results from this study demonstrate the potential of a lake ecosystem model to extract useful process information to complement field data collection and address questions related to the relationship between physical and ecological processes in aquatic ecosystems.

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Nachtrieb, Julie Graham. "The impact of invertebrates to four aquatic macrophytes: Potamogeton nodosus, P. illinoensis, Vallisneria americana and Nymphaea mexicana." Thesis, University of North Texas, 2008. https://digital.library.unt.edu/ark:/67531/metadc9058/.

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This research investigated the impact of invertebrates to four species of native aquatic macrophytes: V. americana, P. nodosus, P. illinoensis, and N. mexicana. Two treatments were utilized on each plant species, an insecticide treatment to remove most invertebrates and a non-treated control. Ten herbivore taxa were collected during the duration of the study including; Synclita, Paraponyx, Donacia, Rhopalosiphum, and Hydrellia. Macrophyte biomass differences between treatments were not measured for V. americana or N. mexicana. The biomasses of P. nodosus and P. illinoensis in non-treated areas were reduced by 40% and 63% respectively. This indicated that herbivory, once thought to be insignificant to aquatic macrophytes, can cause substantial reductions in biomass.

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Pletcher, Leeanna. "The Ecology of Fear: Oviposition and Colonization in Aquatic Systems." VCU Scholars Compass, 2008. http://scholarscompass.vcu.edu/etd/1587.

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Amphibians and aquatic invertebrates have complex life histories that link aquatic and terrestrial food webs. It has been suggested that amphibian reproduction is an important source of carbon to some aquatic systems. This process of energy flow may be shaped by shifts in habitat selection in response to predators. We hypothesized that predators decrease colonization and oviposition of prey, reducing active inputs. Thus predation risk is expected to shift the relative amounts of active and passive subsidies. We manipulated the presence of fish predators in aquatic mesocosms. Results suggest hylid treefrog eggs and hydrophilid beetles were less abundant in predator treatments. This difference in oviposition and colonization translated into small reductions in calories and ash free dry mass of active inputs. However, passive allochthonous inputs were more than double active amounts and variable, therefore relative amounts of active and passive inputs did not differ across the levels of predation risk.

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Silva, Carolina Vieira da. "Macroinvertebrados associados à macrófitas aquáticas flutuantes : distribuição, estrutura da comunidade e abordagem experimental /." Botucatu, 2015. http://hdl.handle.net/11449/140219.

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Orientador: Raoul Henry
Banca: Virgínia Sanches Uieda
Banca: José Francisco Gonçalves Júnior
Banca: Irineu Bianchini Júnior
Banca: Janet Higuti
Resumo: Não disponível
Abstract: Not available
Doutor

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Montemarano, Justin Joseph. "Biotic controls of decomposition dynamics in aquatic systems." Thesis, Kent State University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3618862.

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While environmental controllers of decomposition have been extensively studied, organic matter quality and biotic controllers of decomposition, such as detritivore preference and manipulation of detritus, are largely understudied. In the studies described in this dissertation, a range of biotic controllers of detrital dynamics in aquatic ecosystems are presented. Crayfish, as model shredders, produce a diverse pool of fine particulate organic matter (FPOM) through fragmentation of coarse particulate organic matter (CPOM) and fecal production in the laboratory. Crayfish process maple leaves at a greater rate than oak leaves, and produced a greater amount of FPOM from maple compared to oak. Crayfish-generated FPOM had lower C:N ratios and increased bacterial abundances compared to original CPOM. Further, hydropsychid caddisfly and simuliid blackfly larvae confer greater growth efficiency when reared on crayfish-generated FPOM compared to mechanically ground FPOM in the laboratory, indicating that crayfish increase bioavailability of FPOM. No differences in growth or metamorphosis of simuliid larvae were observed when larvae were lab-reared on crayfish-generated FPOM from CPOM of different tree species (i.e., sugar maple, sycamore, or white oak) or different stream conditioning times (i.e. , 30 or 150 d). This suggests that crayfish processing reduces organic matter origin effects on bioavailability. Changes in macrophyte abundance in a tropical wetland due to competition and ecosystem management can affect litter availability and litter quality. In two field-based, replacement series experiments with floating-mat macrophytes (Eichhornia crassipes and Neptunia oleracea), no interspecific competition was detected. However, E. crassipes dominated experimental enclosure biomass through attrition. Decomposition rates were faster for E. crassipes litter compared to N. oleracea litter within enclosures, but no differences in decomposition rates were detected by floating-mat species composition. Both synergistic and antagonistic diversity effects were observed on decomposition dynamics in an experiment varying litter richness from one to five species. Additionally, cattail (Typha domingensis ) eradication efforts lead to changes in the decomposition landscape within the wetland, as E. crassipes colonizes managed areas, and decomposition rates were slower for litter of T. domingensis compared to E. crassipes. The compounding effects of litter species, detritivore interactions, and anthropogenic impacts on organic matter dynamics illustrate that it is critical to consider ecosystem function in ecosystem management.

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Milligan, Heather. "Aquatic and terrestrial foraging by a subarctic herbivore: the beaver." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32290.

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Freshwater and terrestrial ecosystems are tightly linked by food web interactions. Naturally occurring carbon and nitrogen stable isotopes provide a tool to quantify nutrient flows across ecological boundaries, however their application to freshwater-terrestrial systems has been limited. This thesis evaluated whether stable isotope analysis can be effective in differentiating freshwater and terrestrial vascular plants at the base of subarctic food webs and found freshwater plants to be consistently enriched in their isotopic signatures relative to terrestrial plants. Stable isotope approaches were then used to investigate spatial and temporal variability in the diet of a population of subarctic beavers (Castor canadensis). Freshwater macrophytes contributed more to the diets of beavers than previously reported. During the winter, beavers from pond habitats consumed more aquatic vegetation than beavers from stream habitats which relied more heavily on food hoards of terrestrial vegetation. Aquatic foraging may enable beavers to persist at the northern periphery of their range by reducing foraging pressure on the subarctic terrestrial ecosystem where their preferred tree species are scarce.
Les écosystèmes d'eau douce et terrestres sont liés par les interactions trophiques. Les isotopes stables naturels de carbone et d'azote offrent une méthode pour quantifier les transferts de nutriments entre les frontières écologiques, mais leurs applications aux systèmes d'eau douce-terrestres sont encore limitées. Cette thèse évalue l'efficacité des isotopes stables pour distinguer les plantes vasculaires d'eau douces et terrestres qui forment la base des chaînes alimentaires subarctiques. Nous avons trouvé qu'en général les plantes aquatiques avaient des signatures isotopiques enrichies par rapport aux plantes terrestres. Nous avons ensuite employé les techniques d'isotopes stables pour évaluer la variabilité spatiale et temporale dans le régime alimentaire d'une population de castors (Castor canadensis) subarctiques. Les macrophytes aquatiques semblent avoir une place plus importante dans le régime alimentaire des castors en comparaison avec la littérature disponible. Durant l'hiver, les castors qui habitaient les lacs ont consommé plus de végétation aquatique par rapport aux castors qui habitaient dans les rivières, ceux-ci comptant plutôt sur les provisions de végétation terrestre. L'accumulation de provisions constituées de plantes aquatiques peut permettre aux castors de persister à la limite de leurs aires de distribution où les arbres préférés des castors sont rares. Ainsi, ce phénomène pourrait réduire la pression des herbivores sur ces écosystèmes terrestres à faible productivité.

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Jonsson, Sandra. "Trait and density mediated indirect effects in a three trophic level aquatic system with Asellus aquaticus and Aeshna." Thesis, Umeå University, Ecology and Environmental Science, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-22294.

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Rocha, Tiago de Carvalho Franca [UNESP]. "Mapeamento da sensibilidade ambiental do litoral de Ubatuba-SP a vazamentos de petróleo." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/92795.

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Aproximadamente 10% da poluição global nos oceanos são oriundos de derramamento de óleo e derivados originados do transporte marítimo. Como medida de precaução aos impactos gerados e com o objetivo de minimizar os danos, governos e empresas vêm estruturando a preparação e o planejamento para resposta a estes incidentes. As cartas de sensibilidade a vazamento de óleo (cartas SAO) constituem um dos principais instrumentos de gerenciamento e balizamento das ações de combate e limpeza dos ambientes costeiros atingidos por óleo. Constituem uma ampla fonte de informação sobre a zona costeira, principalmente referente à faixa litorânea, apresentando informações geográficas relativas aos aspectos socioeconômico, biológico-ecológicos e geomorfológicos. O presente estudo apresenta como objetivo geral a elaboração de cartas SAO da porção continental do litoral do município de Ubatuba, São Paulo, apresentando um amplo diagnóstico das características ambientais da área. A metodologia adotada foi baseada nas Especificações e Normas Técnicas para Elaboração das Cartas de Sensibilidade Ambiental a Derramamentos de Óleo, e seus Anexos, desenvolvida pelo Ministério do Meio Ambiente (MMA, 2004). As cartas SAO apresentadas possuem caráter operacional, na escala de 1:30.000 e tático 1:80.000, o que possibilita uma elevada escala de detalhes. O município de Ubatuba representa a região mais preservada e conservada de todo o litoral norte paulista, abrigando, em aproximadamente 200 quilômetros de linha de costa, ecossistemas com alto índice de sensibilidade ao óleo. È representado por seis pequenas baías, com 76 segmentos de praias, 118 de litoral rochoso, 8 barras de rio e 4 estruturas artificiais, além de fragmentos de manguezal, planícies de maré, laguna e lagoas. Muitos destes ecossistemas se encontram em área protegida por unidades de conservação, com difícil...
Approximately 10 % of the global pollution in the oceans is originated from oil and spills derivates that come from the sea transportation. Like measure of precaution to the produced impacts and with the objective to minimize the damages, governments and enterprises are structuring the preparation and the projection as an answer to these incidents. The sensitivity to leak of oil letters (“cartas SAO”) constitute one of the most important management and marking instruments of combat and cleaning of the coastal environments reached by oil actions. They constitute an important source of information about the coastal zone, specially referring to the shoreline, presenting geographical information related to the socioeconomic, biologicalecological and geomorphologic aspects. The present study presents as a general objective the preparation of “cartas SAO” from the continental portion of the Ubatuba county coast, in Sao Paulo, presenting a rich diagnosis of the environmental characteristics of the area. The adopted methodology was based on the Specifications and Technical Standards for Preparation of the Environmental Sensitivity to Spilling of Oil Letters, and its annexes, developed by the “Ministério do Meio Ambiente”, Brazil (MMA, 2004). The “cartas SAO” presented have operational character, in the scale of 1:30.000 and tactic 1:800.000, which makes an elevated scale of details possible. The Ubatuba County represents the most preserved region of the whole São Paulo northern coast, sheltering, in approximately 200 kilometers coast line, ecosystems with high rate of oil sensitivity. It’s represented by six small bays, with 76 beaches segments, 118 of rocky coast, 8 estuaries and 4 artificial structures, besides mangrove fragments, tide plains, lagoon and ponds. A great deal of these ecosystems is in protected by conservation unities area, with difficult access, and others are... (Complete abstract click electronic access below)

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Câmara, Flôr de Maria Mendes [UNESP]. "Avaliação da qualidade da água do rio Poti na cidade de Teresina, Piauí." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/104342.

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Convenio Ifpi
O rio Poti tem suas nascentes no estado do Ceará, possui uma extensão de 550Km e chega ao estado do Piauí pelo município de Castelo do Piauí, desembocando no rio Parnaíba na capital, Teresina, onde desempenha papel de grande importância para a população, principalmente pelo fornecimento de pescados, de mineração (areia) para a construção civil, utilização para a agricultura de subsistência (vazante) e lazer (balneabilidade). Atualmente, é possível observar que este manancial está sofrendo grandes impactos de diversas naturezas, principalmente pela ação antrópica, o que tem modificado as suas características ambientais. Este trabalho tem como objetivo avaliar a qualidade da água do rio nos períodos de cheia e estiagem nas zonas urbana e rural do município de Teresina, por meio de analises de parâmetros físico-químicos e biológicos, do mapeamento das atividades potencialmente poluidoras, da verificação das relações entre as características climáticas e os indicadores da qualidade da água, visando a sua classificação de acordo com a legislação do Conama e sua adequabilidade para os diversos usos. Os parâmetros analisados foram: pH, condutividade elétrica, oxigênio dissolvido, turbidez, sólidos totais, nitrito, nitrato, fósforo, temperatura da água, transparência da água, clorofila e coliformes fecais (termotolerantes), totais e fitoplâncton. A pesquisa foi feita em 52 km de rio, em pontos de coleta localizados nas margens e na superfície. Os resultados obtidos demonstraram que, em geral, não houve diferenças significativas espaço-temporais dos parâmetros físico-químicos e biológicos analisados, e que somente os parâmetros turbidez, nitrito e fósforo estão em desacordo com a legislação do CONAMA nº 357/05 na maioria dos...
Poti River have their sources on Ceará state, has a extension of 550km and arrives at Piauí state in the city of Castelo do Piauí, flowing in Parnaíba river in the capital, Teresina, where it plays a very important role for the population, principally by supply of fish, mining (sand) for the construction, use for subsistence agriculture (ebb) and recreational (bathing). Today, it is observed that this source is suffering large impacts of various types, especially by anthropic action, which has modified your environmental characteristics. This study aims to evaluate the quality of the river water during periods of flood and drought in the urban and rural zones of the city of Teresina, through analysis of physical parameters biological and chemical of the mapping of potentially polluting activities, verification of relationship between climate characteristics and indicators of water quality in order to classify them according to the legislation of Brazil National Conuncil of Environment (Conama) and their suitability for various uses. The parameters analyzed were pH, electrical conductivity, dissolved oxygen, turbidity, total solids, nitrite, nitrate, phosphorus, water temperature, water transparency, chlorophyll and fecal coliforms (thermotolerant) total coliforms and phytoplankton. The survey was conducted in 52 km of river, in collection points located on the margins and on the surface. The results demonstrated that, in general, no significant differences were of space-time physical, chemical and biological parameters analysis, and that only the parameters turbidity, nitrate and phosphorus are in disagreement with the Conama Resolution No. 357/2005 on most of the points studied. Individuals have been identified to genus level distributed in the Divisions Cyanophyta, Euglenophyta, Bacillariophyta and Chlorophyta. These genres were present at... (Complete abstract click electronic access below)

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Wachholz, Flávio [UNESP]. "Influência da bacia hidrográfica e características espaço-temporais de variáveis limnológicas sobre reservatórios no Rio Jacuí - RS." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/104345.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
A construção de barragem é uma intervenção antrópica na rede de drenagem que altera o fluxo natural da água. O presente trabalho caracterizou e analisou a estruturação limnológica e espectral na escala espaço-temporal nos reservatórios das Usinas Hidrelétricas (UHE) Passo Real e Dona Francisca do rio Jacuí – RS, e a relação com as bacias hidrográficas que os compõem no Alto Jacuí. A hipótese foi a de que ocorrem diferenças nas propriedades ópticas da água na escala espaço-temporal de reservatórios em função das próprias características e de suas bacias hidrográficas. Os procedimentos metodológicos foram: 1) adquirir dados limnológicos (transparência Secchi, temperatura, total de sólidos em suspensão - TSS, carbono orgânico dissolvido e clorofila a) e de espectrorradiometria de campo (dados hiperespectrais) do período de fevereiro de 2009 a março de 2010; 2) construção de um banco de dados com os elementos da bacia hidrográfica (geossistema e sistema socioeconômico) e as variáveis limnológicas na perspectiva espaço-temporal; 3) identificação das fragilidades da bacia hidrográfica e as características dos reservatórios que interferem na qualidade da água; 4) relacionar os dados espectrais com os dados limnológicos para verificar o potencial destes no monitoramento dos reservatórios. Os resultados mostraram que a bacia hidrográfica do reservatório Passo Real, com relevo colinoso, apresenta dominância de uso do solo com agricultura, com destaque para as culturas da soja no verão e trigo no inverno. O reservatório Dona Francisca, na base da série em cascata de reservatórios, recebe o tributário Jacuizinho, cuja bacia hidrográfica é de relevo de morros, os principais usos da terra são florestas e campos. A temperatura da água para ambos os reservatórios é inferior a 20ºC nos meses de inverno...
The building of a dam is an anthropic intervention in the drainage system that changes the natural water flow. This work has characterized and analyzed the limnological and spectral structure on a spatial and temporal scale of the freshwater reservoirs Hidropower Plants (HPP) Passo Real and Dona Francisca of the river Jacuí – RS and, the relationship with the hydrographic basins that make up on the Alto Jacuí. The relationship with the hydrographic basins that make they up on the Alto Jacuí. The hypothesis was that the optical proprieties varies on the spatial and temporal scale as a function of the own reservoir proprieties as well of the hydrographic basins. The methodological procedures were: 1) limnological data acquisition (Secchi transparency, temperature, total of suspended solids - TSS, dissolved organic carbon and chlorophyll a) and field spectroradiometry (hyperspectral data) of the period from February 2009 to March 2010; 2) data base elaboration with the hydrographic basin elements (geosystem and social-economic system) and the limnological variables at the spatial and temporal perspective; 3) identification of the fragility areas of the hydrographic basin and the reservoir characteristics that affect the water quality; 4) relation analysis between the spectral and the limnological data to verify the potential of these to reservoir monitoring. The results showed that Passo Real reservoir hydrographic basin, with a hilly relief, has land use predominance of agriculture, especially for crops such as soybean in the summer and wheat at the winter season. The Dona Francisca reservoir, which is in the basis of the sequence of reservoirs, receives the tributary named Jacuizinho, has a relief characterized by hills and land use with predominance of forest and open fields. In both reservoirs the water temperature is... (Complete abstract click electronic access below)

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Watson, Troy Norton. "The structuring of aquatic macroinvertebrate communities within cave streams." Thesis, University of Canterbury. Biological Sciences, 2010. http://hdl.handle.net/10092/6513.

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The unusual environmental conditions within caves provided unique opportunities for developing an understanding of ecosystem processes. However, relatively few studies have been conducted on the ecology of New Zealand cave systems. The primary aim of this research was to investigate changes in aquatic invertebrate communities along a longitudinal gradient from the surface into caves and investigate the fundamental drivers of cave communities. This study was carried out in three streams (two in pasture catchments and one in a forested catchment) flowing into caves in the Waitomo region, North Island, New Zealand. In order to address these aims I carried out a longitudinal survey of 12 sites in each stream, an experimental manipulation of food, and an isotopic study of a single stream. The longitudinal survey of the three cave streams revealed light intensity as well as algal and CPOM biomass all decreased significantly from outside the caves into caves. In contrast, water temperature, dissolved oxygen, stream width, depth, and velocity did not vary significantly with distance into caves. Benthic aquatic macroinvertebrate communities within the caves were a depauperate subset of surface communities, appearing to be structured by gradients in resources and colonisation through drift. However, some invertebrate taxa (primarily predators) were rarely found within caves, further suggesting that resource gradients were structuring cave communities. Surprisingly, the densities of some collector-browsers (primarily mayflies) increased within cave streams relative to surface densities. This may be due to a decrease in competition and predation, flexible feeding strategies, and high drift propensity. However, the benthic densities of most taxa within the caves appeared to be related to drift densities. Although surface forest and pastoral stream communities differed in community composition and density 32 meters within the caves invertebrate community diversity and density became similar, although specific taxa within communities varied. This convergence was attributed to similar environmental gradients within the caves. The resource addition experiment (adding leaf packs) indicated that cave streams were resource limited; the addition of leaves produced communities of similar richness and density across the environmental gradient. The isotopic survey suggested cave stream invertebrate communities were reliant upon similar basal resources to surface streams. However, within the cave epilithon appeared to be increasingly important while filamentous algae were absent. Cave aquatic invertebrates were also found to support terrestrial predators (spiders, harvestmen, and glow-worms), presumably increasing the abundance and diversity of terrestrial cave communities. In conclusion, aquatic cave communities were reliant upon surface derived resources and consequently strongly linked to surface land-use and managerial practices.

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Sottolano, Dane Anthony. "Substrate particle size preference of the caddisfly Macrostemum zebratum (Hagen) (Trichoptera: Hydropsychidae) in small stream riffle." Instructions for remote access. Click here to access this electronic resource. Access available to Kutztown University faculty, staff, and students only, 1990. http://www.kutztown.edu/library/services/remote_access.asp.

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Nachtrieb, Julie G. Kennedy James H. "The impact of invertebrates to four aquatic macrophytes Potamogeton nodosus, P. illinoensis, Vallisneria americana and Nymphaea mexicana /." [Denton, Tex.] : University of North Texas, 2008. http://digital.library.unt.edu/permalink/meta-dc-9058.

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Kautza, Adam Robert. "Consequences of landscape change on riverine food webs and aquatic-terrestrial linkages." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1408719548.

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Yanoviak, Stephen P. "Community ecology of water-filled tree holes in Panama /." Full-text version available from OU Domain via ProQuest Digital Dissertations, 1999.

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Perry, William B. "Ecology and energetics of an aquatic detritivore, Pteronarcys proteus (Plecoptera: Pteronarcyidae)." Diss., Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/76473.

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Life history, food habits, energetics, and production by nymphs of Pteronarcys proteus were measured. The life cycle lasted four years in an Appalachian mountain stream in southwestern Virginia. Adults emerged late May to early June, and eggs deposited did not hatch until the following spring. Nymphs grew at least 3 years with 12 male instars and 13 female instars. The nymphal diet was primarily leaf detritus, with a small percentage of moss and animal matter. Total crude lipid content of nymphs varied from 6% to 29% of dry insect weight and was dependent on age, season, and developmental state. Lipid content of nymphs in the two youngest cohorts generally declined during late summer, but increased after leaf-fall in November. A similar pattern was observed in the oldest cohort, but a significant decline in the spring prior to emergence of adults was also observed. The data indicate that P. proteus relied on lipid stores during periods of low food availability and for reproductive maturation. The energetic parameters of growth (G), respiration (R), ingestion (I), and egestion (E) for nymphs in each of the three cohorts were measured in the laboratory. Growth rates ranged from 0.031 to 0.0037 mg/mg/day, with small nymphs growing fastest. Ingestion ranged from 5 to 40% of dry body weight per day. Respiration ranged from 330 to 980 µl O₂/g/hr. Mean AD was 13.5%, mean gross growth efficiency was 5.2%, and mean net growth efficiency was 38.7%. Total assimilation by a population was estimated at 119 kcal m⁻², accounted for primarily by the two oldest cohorts. Annual energetics of the nymphal population were: I= 906, G= 41, R= 78, and E= 828 kcal m⁻². Annual production was 0.438 g m⁻², 3.158 g m⁻², and 4.182 g m⁻², with the youngest cohort contributing the smallest. Mean cohort densities ranged from 23.8 to 9.3 nymphs m⁻², and mean standing stock biomass ranged from 0.143 to 1.790 gm⁻². Mean relative growth rates (RGR) in the stream were greatest for smallest nymphs and ranged from 0.939 to 0.182 percent increase per day. The data indicate that growth rates of small nymphs were influenced by temperature and larger nymphs by food supply. It was estimated that P. proteus consumed 41-61% of the litterfall in the study stream.
Ph. D.

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Perusse, Martin. "Metal cycling in terrestrial and aquatic ecosystems." Thesis, McGill University, 1990. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=59848.

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The present study examines the cycling of elements in the biosphere. The first chapter proposes a theoretical framework for this cycling based on both metal/ligand theory and mass balance studies. Empirical modelling serves as an alternative and complement to mass balance studies in predicting the export of elements from watersheds. Watershed output (export per unit area per unit of time) is predicted using atmospheric deposition rates, an element bonding strength index, the watershed area and a forest classification (deciduous vs coniferous). Finally the last chapter examines, in a speculative fashion, the partitioning of elements between the atmosphere and hydrosphere as a function of element behaviour and discusses the ecological consequences of human activity on this partitioning.

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Rine, Kristin M. "Trophic pathways supporting juvenile chinook and coho salmon in the glacial Susitna River, Alaska| Patterns of freshwater, terrestrial, and marine resource use across a seasonally dynamic habitat mosaic." Thesis, University of Alaska Fairbanks, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1605432.

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In large, seasonally dynamic and spatially complex watersheds, the availability and relative importance of various food resources for stream fishes can be expected to vary substantially. While numerous studies have attempted to uncover the trophic linkages that support stream salmonids, much of these efforts have occurred at small scales that disregard variability of food resources inherent in lotic systems. This study aimed to determine large-scale patterns in the contributions of freshwater, terrestrial, and marine-derived food resources to juvenile Chinook and Coho salmon (Oncorhynchus tshawytscha and O. kisutch) in the large, glacially influenced Susitna River, Alaska. I quantified diet patterns both spatially, across different macrohabitat types positioned along a 169-km segment of the river corridor, and temporally, from June to October, using stable isotope and stomach content analyses. To further resolve energy pathways from basal carbon sources to juvenile salmon, I determined the relative roles of terrestrial organic matter and freshwater periphyton food sources to aquatic benthic invertebrate diets. The latter analysis showed that invertebrate consumers were more reliant on freshwater periphyton than on terrestrial organic matter. Bayesian stable isotope mixing models indicated that juvenile salmon in the middle Susitna River were, in turn, largely supported by freshwater invertebrate prey regardless of spatial and temporal context. The relative contribution of marine-derived prey (salmon eggs) to juvenile salmon diets was greatest in the fall within tributary mouth and off-channel macrohabitats during both years of the study. Terrestrial invertebrate prey contributions were generally greatest during mid-summer within all macrohabitat types sampled, however this pattern varied across years. No upstream to downstream diet pattern was apparent from the data. These results underscore the importance of freshwater energy pathways for sustaining juvenile Chinook and Coho salmon in the Susitna River and provide further spatial and temporal context for the importance of pulsed marine and terrestrial prey subsidies. As Pacific salmon stocks continue to decline, management and mitigation efforts should operate on knowledge gained from studies that encompass the large-scale spatial and temporal variability inherent in riverine landscapes.

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Cunillera-Montcusí, David. "Resilience of aquatic metacommunities: implications for disturbance recovery." Doctoral thesis, Universitat de Girona, 2020. http://hdl.handle.net/10803/669784.

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During the last years, there has been an increase in the number and intensity of disturbances, and their consequences related with global change, which have corroborated the already forecasted scenarios. One example are wildfires, which are expected to increase both in intensity and extension in the near future. However, although the extensive research carried out to understand wildfire impacts, there is still a lack of knowledge regarding its consequences on freshwater temporary ponds. These temporary habitats constitute small biodiversity reservoirs, holding singular and iconic fauna. Nowadays, these habitats are endangered mostly due to habitat loss. Consequently, to cope with the future climatic scenario, which predicts an increase in wildfire disturbances as well as greater habitat loss, it becomes mandatory to better comprehend and study wildfire impacts on these small biodiversity jewels.Throghout this thesis I study the Jonquera wildfire consequences on the Albera temporary ponds
Durant els últims anys, l’increment de pertorbacions lligades al context de canvi global està corroborant cada dia els pronòstics més negatius. En aquesta mateixa línia, i en relació a les pertorbacions d’abast regional com els incendis, les prediccions no fan res més que pronosticar-ne un augment, tant en la intensitat com en l’extensió. Tanmateix, tot i la gran quantitat de recerca sobre els impactes dels incendis se sap poc en relació al seu impacte sobre els estanys temporanis d’aigua dolça. Aquests, constitueixen un reservori de biodiversitat únic i molt valuós en les regions com la Mediterrània i actualment es troben greument amenaçats a causa de la seva desaparició. En conseqüència, davant de les futures perspectives climàtiques d’increment dels incendis i d’una major pèrdua d’habitat, esdevé cabdal conèixer quins són els impactes dels incendis sobre els estanys temporanis mediterranis. En aquesta tesi s'aprofundeix en els afectes de l'incendi de la Jonquera sobre els estanys temporanis de l'Albera

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Kimble, Matthew Sidney. "Variation of aquatic and terrestrial riparian biodiversity in response to watershed condition /." Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/5527.

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Costa, Daiana Marques [UNESP]. "Estabelecimento de um índice de sensibilidade ambiental ao óleo em ambientes fluviais, com o suporte da ferramenta MORPH." Universidade Estadual Paulista (UNESP), 2013. http://hdl.handle.net/11449/92737.

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A presente pesquisa propõe um sistema de classificação que visa determinar a sensibilidade ambiental ao óleo dos diversos ambientes fluviais. Esse sistema de classificação se baseou nos principais sistemas existentes utilizados na atualidade pela National Oceanic and Atmospheric Administration (NOAA), para os principais sistemas fluviais e Grandes Lagos norte americanos e pela Petrobras, para os rios amazônicos. Essa proposição se deve em razão da recorrência cada vez maior de acidentes envolvendo derramamento de óleo em áreas continentais, com consequentes danos ambientais aos cursos fluviais e por não haver um sistema de classificação abrangente, que atenda aos mais diversos tipos de ambientes encontrados em cursos fluviais, pois grande parte dos estudos de sensibilidade estão voltados aos ambientes costeiros. Com isso, para uma melhor avaliação das bibliografias existentes sobre estes sistemas, foi utilizada uma ferramenta de análise denominada MORPH (Modelo Orientado a Representação do Pensamento Humano). Esta ferramenta auxiliou na comparação de muitas variáveis interdependentes, o que possibilitou a identificação dos parâmetros físicos fundamentais utilizados para determinar os principais ambientes que compõem o sistema de classificação. Como resultados foram obtidos os parâmetros físicos fundamentais que devem ser observados para avaliar a sensibilidade ambiental ao óleo, como: tipo e natureza do substrato (substrato rochoso, substratos inconsolidados, estruturas artificiais, substratos vegetados), ação do hidrodinamismo, declividade das feições marginais, fácies dos sistemas deposicionais fluviais e presença de vegetação. Com base nesses parâmetros e nos sistemas de classificação existentes, oito ambientes fluviais foram selecionados para compor um sistema denominado Índice de Sensibilidade Fluvial (ISF). Este sistema propõe que os seguintes ambientes sejam considerados: margens rochosas...
The present study proposes a classification system that aims to determine the environmental sensitivity to oil in various water way settings. This classification system is based on the main existing systems used today by the National Oceanic and Atmospheric Administration (NOAA), for the most important North American rivers and Great Lakes, and by Petrobras, for the Amazon rivers. This proposal came about because of ever increasing reoccurrences of oil spills in areas on the continent, with consequent environmental damage to water ways, and because there is no broad classification system that meets the needs of the different types of environments found in water ways, seeing that a good part of the sensitivity studies are directed towards coastal settings. Therefore, so as to have a better assessment of existing bibliographies on these systems, an analysis tool was used, which is called Human Thinking Representation Oriented Model (MORPH). This tool simplified the comparison of many interdependent variables, which made it possible to identify the fundamental physical parameters used to determine the main environments that make up the classification system. As a result, the fundamental physical parameters that should be observed to evaluate environment sensitivity to oil, like for instance: type and nature of the substrate (rock substrate, unconsolidated substrates, artificial structures, vegetated substrates), hydrodynamic effect, river sloping features, system depositional surfaces, and vegetation presence. Based on these parameters and on existing classification systems, eight river environments were selected to make up one system, which was named the Fluvial Sensitivity Index (FSI). This system proposes that the following environments be considered: rocky shores, artificial structures, beaches, muddy substrate banks, point-bars, natural dikes, vegetated shores and flood plains associated with vegetation. The FSI classified each...

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Paterson, Jaclyn. "Response of an introduced aquatic predator, the Nile perch, to environmental change." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=32531.

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Fishing is a potent ecological force that can impact the density and distribution of fish stocks as well as fitness-related traits. In this thesis I examined eco-phenotypic change in the introduced Nile perch of Lake Nabugabo (East Africa) in response to decades of intense fishing pressure. I quantified temporal (12 years) and spatial variation (wetland vs. exposed habitats) in the a) size, b) catch per unit effort, c) diet, and d) gill morphology of Nile perch, by comparing field data collected in 2007 to earlier studies (1995, 2000 for distribution and diet and 1996 for gill morphology). Nile perch are now less abundant and smaller, and a larger proportion of the population is found near wetlands than in 1995. Relative to open waters, Nile perch near wetlands consume a higher proportion of cichlids, shift to piscivory at a smaller size, and have larger gills. Sustainability of the Nile perch fishery will demand adaptive management that accounts for rapid eco-phenotypic change in the stocks.
La pêche est une force écologique puissante qui peut avoir des impacts non seulement sur la densité et la distribution des stocks de poissons mais également sur les traits reliés à la valeur adaptative. Dans cette thèse, j'ai examiné un changement éco-phénotypique en réponse à plusieurs décennies de pêche intensive chez la Perche du Nil, une espèce introduite, dans le lac Nabugabo (Afrique de l'est). J'ai quantifié la variation temporelle (sur 12 ans) et spatiale (milieux humides vs. habitats exposés) de: a) la taille de la Perche du Nil, b) des prises par unité d'effort, c) de la diète, et d) des branchies en comparant les données de terrain récoltées en 2007 avec des données d'études antérieures (1995, 2000 et 1996 pour les branchies). La Perche du Nil est maintenant moins abondante et de taille inférieure comparé à la population échantillonnée en 1995. En 2007, une plus grande proportion de la population se retrouve près des milieux humides comparé à la population en 1995. La Perche du Nil retrouvée près des milieux humides consomme une plus grande proportion de cichlidés, a modifié son régime alimentaire en devenant piscivore à de petite tailles et a développé des branchies plus larges comparé aux Perches retrouvées en milieu pélagique. Pour perpétuer une exploitation durable des stocks de Perche du Nil, les gestionnaires des pêcheries devront s'adapter et tenir compte de ce rapide changement éco-phénotypique dans la population.

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Twitchen, Ian Douglas. "The physiological bases of resistance to low pH amongst aquatic insect larvae." Thesis, Lancaster University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.305951.

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Gilleland, Sarah. "Investigating Late Woodland-Period aquatic catchments through freshwater mussel assemblage composition." Thesis, Mississippi State University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10141579.

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During the Late Woodland Period in the American Southeast, the amount of space that any individual group could exploit began to shrink, due to the presence of other groups on the landscape. Resource expansion occurred to augment food supplies, resulting in increased exploitation of mussel beds. Because mussels can be extremely sensitive to the characteristics of the waterways they live in, the specific habitat requirements of these animals can be used to reconstruct the environments they were recovered from. In this thesis I use freshwater mussel assemblages to reconstruct hypothetical aquatic catchments and map them onto modern rivers in the Yazoo River Basin and the Tombigbee River Basin. These are used to test ethnographic models of exploited space. I also use detrended correspondence analysis to test if sites exist in mathematical space like they do in physical space along the Yazoo River basin, as observed in the Tombigbee River basin.

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Dissertations / Theses on the topic 'Aquatic ecology'

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