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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

Variações na estrutura das assembléias de peixes ao longo de um amplo gradiente estuarino-límnico do complexo Lagunar Patos-Mirim

Moura, Priscila Martins de January 2011 (has links)
Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2011. / Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-12-16T03:31:29Z No. of bitstreams: 1 Priscila Martins de Moura.pdf: 499869 bytes, checksum: 89e9bd15d4cf51cf14c19da5f5c8c309 (MD5) / Approved for entry into archive by Sabrina Andrade (sabrinabeatriz@ibest.com.br) on 2013-12-18T17:58:11Z (GMT) No. of bitstreams: 1 Priscila Martins de Moura.pdf: 499869 bytes, checksum: 89e9bd15d4cf51cf14c19da5f5c8c309 (MD5) / Made available in DSpace on 2013-12-18T17:58:11Z (GMT). No. of bitstreams: 1 Priscila Martins de Moura.pdf: 499869 bytes, checksum: 89e9bd15d4cf51cf14c19da5f5c8c309 (MD5) Previous issue date: 2011 / A presente dissertação é composta de um capítulo (em Português) sintetizando os principais resultados obtidos, os quais são apresentados na forma de um manuscrito (em inglês) no apêndice. O principal objetivo foi analisar o padrão de distribuição das assembléias de peixes e a influência de algumas variáveis ambientais na abundância relativa das espécies dominantes ao longo de um amplo eixo espacial (~300 km), englobando o estuário da Lagoa dos Patos, canal São Gonçalo e Lagoa Mirim. No total, sete locais foram amostrados mensalmente entre 03/2004 e 02/2005 com uma rede de arrasto em zonas rasas (< 2 m). Foram capturadas 63 espécies e 45.929 indivíduos. As análises de escalonamento multidimensional (MDS) evidenciaram a presença de dois grupos principais espacialmente distintos: um formado pelas amostras do estuário e outro formado pelo Canal São Gonçalo e Lagoa Mirim. Os peixes foram agrupados em guildas ecológicas e, através da análise de composição e abundância relativa, verificou-se uma marcada substituição dessas guildas entre a zona estuarina (estuário e norte do canal) e zona límnica (sul do canal e Lagoa Mirim). Essa substituição foi mais pronunciada em termos de abundância do que em termos de frequência de ocorrência, sendo que a segregação entre as guildas foi intensificada pela presença de uma barragem-eclusa, posicionada na porção mediana do gradiente. Variáveis físico-químicas (e.g., salinidade e transparência da água) e outras relacionadas às características estruturais dos habitats (e.g., declividade e percentual de silte e argila no sedimento) foram os principais fatores, dentre os investigados, que melhor explicaram a variabilidade na abundância e distribuição da ictiofauna ao longo do gradiente. / This dissertation is comprised of a chapter (in Portuguese) summarizing our main findings, which are shown in a manuscript (in English) in the annex. Our main goal was to analyze the distribution pattern of fish assemblages and the influence of some environmental variables on the relative abundance of dominant species along a broad spatial axes (~300 km), including the Patos Lagoon estuary, São Gonçalo channel and Mirim Lake. A total of seven sites were sampled monthly between 03/2004 and 02/2005 with a beach seine in shallow areas (<2 m). A total of 63 fish species and 45.929 individuals were caught. The multidimensional scaling (MDS) analyses revealed two main groups spatially distinct: one formed by the estuarine samples and other by freshwater samples from the channel and the Mirim. Fish species were grouped into ecological guilds and the analyses of their composition and relative abundance revealed a marked substitution of ecological guilds between the estuarine zone (estuary and northern portion of the channel) and the limnetic zone (southern portion of the channel and Mirim). This substitution was more pronounced in terms of abundance than in terms of frequency of occurrence. Guilds segregation was intensified by the presence of a dam lock positioned in the middle portion of the gradient. Physico-chemical variables (e.g., salinity and water transparency) and others related to the structural characteristics of habitats (e.g., slope and percentage of silt and clay in the sediment) were the main factors, among those investigated, that better explained the variability in the distribution and abundance of fish fauna along the gradient.
242

A poluição industrial no "mar de dentro" na perspectiva da educação ambiental crítica e transformadora

Ferreira, Washington Luiz dos Santos January 2014 (has links)
Submitted by Josiane ribeiro (josiane.caic@gmail.com) on 2016-04-06T20:04:37Z No. of bitstreams: 1 0000010616.pdf: 2336069 bytes, checksum: 58182cdbfbd93b1f32bfc75cd6fb082c (MD5) / Approved for entry into archive by cleuza maria medina dos santos (cleuzamai@yahoo.com.br) on 2016-04-15T16:41:17Z (GMT) No. of bitstreams: 1 0000010616.pdf: 2336069 bytes, checksum: 58182cdbfbd93b1f32bfc75cd6fb082c (MD5) / Made available in DSpace on 2016-04-15T16:41:17Z (GMT). No. of bitstreams: 1 0000010616.pdf: 2336069 bytes, checksum: 58182cdbfbd93b1f32bfc75cd6fb082c (MD5) Previous issue date: 2014 / Buscou-se, neste trabalho, investigar, na perspectiva da Educação Ambiental crítica e transformadora, a Poluição Industrial no Estuário da Lagoa dos Patos (RS, Brasil), através de suas aproximações aos campos da História Ambiental, Justiça Ambiental e Gestão Ambiental, bem como sua correlação com a produção acadêmica do Programa de Pós-Graduação em Educação Ambiental da Universidade Federal do Rio Grande. Esta tese foi desenvolvida junto à linha de pesquisa de ―Educação Ambiental: Ensino e Formação de Educadores‖ (EAEFE) do PPGEA-FURG, por articular a discussão do processo de formação de pesquisadores-educadores ambientais da Universidade, focalizado na abordagem sobre a Poluição Industrial, uma das questões socioambientais mais adversas e comprometedoras da qualidade de vida regional. Para tal, foi realizada a revisão bibliográfica e a integração dos dados dispersos relativos ao processo de industrialização regional, os riscos e impactos socioambientais da poluição industrial gerada. Paralelamente, foi efetuada a compilação e análise do conjunto de dissertações de mestrado e teses de doutorado produzidas nos vinte anos do PPGEA (1994-2014). Os resultados descrevem, por um lado, um grande conjunto de conflitos e impactos agudos e crônicos da poluição industrial na região. Por outro ângulo, os resultados indicam uma reduzida amostra da produção do PPGEA direcionada ao tema de pesquisa; porém, apesar de reduzida, esta produção mostra-se crítica e propositiva ao discutir o tema, seus sujeitos/atores, suas causas e repercussões. Por fim, discutem-se as possíveis causas para o fenômeno da invisibilidade relativa do tema de pesquisa, procurando relacionar o papel institucional da Universidade na concepção de um modelo de desenvolvimento regional, social e ambientalmente referenciado. Esta tese reflete também o perfil e trajetória profissional do autor, atuante na Gestão e Educação Ambiental, como pesquisador associado ao ―Laboratório de Gerenciamento Costeiro‖ (Instituto de Oceanografia), e colaborador do ―Observatório dos Conflitos Socioambientais‖ e do ―Grupo de Pesquisa em Justiça Ambiental‖ da FURG, na perspectiva de construção coletiva de um patamar de sustentabilidade e justiça socioambiental regional. / We sought in this study, to investigate, from the perspective of critical and transformative Environmental Education, the Industrial Pollution in the estuary of Patos Lagoon (RS, Brazil), through its approaches to the field of Environmental History, Environmental Justice and Environmental Management, as well as their correlation with the academic production of the Post-Graduate in Environmental Education, Federal University of Rio Grande. This thesis was developed by the line research of "Environmental Education: Education and Training of Educators" (EAEFE) of PPGEA-FURG for joint discussion of the training of environmental educators, researchers at the University process, focused in approach to pollution industrial, one of the most adverse environmental issues and compromising the quality of regional life. To this end, the literature review and the integration of scattered data on the regional industrialization process, risks and social and environmental impacts of industrial pollution generated was performed. In parallel, we make the compilation and analysis of all the dissertations and doctoral theses produced in the twenty years of PPGEA (1994-2014). The results describe, on the one hand, a large group of acute and chronic conflicts and impacts in the area of industrial pollution. From another angle, the results indicate a small sample of the production of PPGEA directed the research topic; however, although reduced, this production proves critical and purposeful to discuss the theme, its subjects / actors, its causes and consequences. Finally, we discuss the possible causes for the phenomenon of relative invisibility of the research topic, trying to relate the institutional role of the University in designing a model of regional, social and environmentally referenced development. This thesis also reflects the profile and career of the author, active in Environmental Management and Education, as associated with the "Laboratory of Coastal Management" (Institute of Oceanography), researcher and contributor to the "Observatory of Social and Environmental Conflict" and "Research Group Environmental Justice "FURG, from the perspective of collective construction of a regional level of sustainability and environmental justice.
243

Influência de fatores ascendentes sobre a produção bacteriana em ecossistemas aquáticos continentais tropicais

Jacques , Saulo Machado de Souza 26 August 2011 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-15T13:59:12Z No. of bitstreams: 1 saulomachadodesouzajacques.pdf: 663956 bytes, checksum: caccb1e96f0e94bf57e712aab0d16d45 (MD5) / Approved for entry into archive by Diamantino Mayra (mayra.diamantino@ufjf.edu.br) on 2016-07-19T15:55:35Z (GMT) No. of bitstreams: 1 saulomachadodesouzajacques.pdf: 663956 bytes, checksum: caccb1e96f0e94bf57e712aab0d16d45 (MD5) / Made available in DSpace on 2016-07-19T15:55:35Z (GMT). No. of bitstreams: 1 saulomachadodesouzajacques.pdf: 663956 bytes, checksum: caccb1e96f0e94bf57e712aab0d16d45 (MD5) Previous issue date: 2011-08-26 / Bactérias heterotróficas são importantes componentes do plâncton, participando ativamente do ciclo do carbono em ecossistemas aquáticos, como por exemplo, através da incorporação de carbono à biomassa pelo processo de produção bacteriana (PB). Alterações nos ecossistemas aquáticos influenciam a atividade bacteriana e, consequentemente, o ciclo do carbono nestes sistemas. Este estudo se propôs a avaliar a influência da temperatura, da concentração de carbono orgânico dissolvido (COD) e da disponibilidade de nutrientes sobre a PB em cinco lagoas costeiras tropicais, que representam um gradiente natural de concentração de carbono (12; 18,3; 46,7; 86 e 117,1 mg/L). Amostras de água de todas as lagoas foram incubadas em três temperaturas diferentes (25, 30 e 35º C), combinadas fatorialmente com a adição de nutrientes: carbono (C), nitrogênio (N), fósforo (P) e nitrogênio + fósforo (NP). Os resultados revelaram que a adição de nutrientes estimulou a PB, mas de maneira distinta em cada uma das lagoas. Em sistemas com maiores concentrações de COD, a adição de C estimulou a PB, enquanto que em lagoas com menores concentrações, a adição de N e P resultou maiores taxas de PB. No geral, o aumento de temperatura afetou negativamente a PB. Segundo os resultados observados, o efeito da temperatura e da adição de nutrientes sobre a PB é dependente de algumas características do estoque de carbono dos ecossistemas aquáticos, como sua qualidade para o consumo bacteriano. Desta forma, espera-se que a temperatura e a qualidade de C sejam mais importantes sobre as taxas de PB em ecossistemas com maiores concentrações de COD húmico, enquanto em ecossistemas com baixa concentração de COD estes dois fatores exercem fraca ou nenhuma influência sobre PB. Diante dos atuais eventos de eutrofização e alterações climáticas, espera-se observar alterações da atividade da comunidade vii bacteriana em ecossistemas aquáticos, com consequência para toda a teia alimentar. Os resultados deste trabalho apontam que fatores como a qualidade do substrato e a estrutura da comunidade bacteriana merecem especial atenção em estudos futuros para uma melhor compreensão da influência da temperatura e de nutrientes sobre a PB em ecossistemas aquáticos húmicos tropicais. / Heterotrophic bacteria are important components of plankton, actively participating in the carbon cycle in aquatic ecosystems and incorporating carbon biomass through the process of bacterial production (BP). Changes in ecosystems influence bacterial activity and thus the carbon cycle in these systems. This study aimed to evaluate the influence of temperature, dissolved organic carbon (DOC) concentration and nutrient availability on the BP in five tropical coastal lagoons, which represented a gradient of carbon concentration (12; 18,3; 46,7; 86 and 117,1 mg/L). Water samples from the lagoons were incubated at three different temperatures (25, 30 and 35º C) factorially combined with the addition of nutrients: carbon (C), nitrogen (N), phosphorus (P) and nitrogen + phosphorus (NP). The results revealed that the addition of nutrients stimulates the BP, but differently in each of the lagoons. In systems with higher DOC concentration, the addition of C stimulated the BP, while in lakes with lower DOC, the addition of N and P resulted in higher BP rates. In general, the temperature increase negatively affected BP. According to the results, the effect of temperature and nutrient addition on the BP is dependent of some characteristics of the carbon stock of aquatic ecosystems, as well on its quality for bacterial consumption. Thus, it is expected that the temperature and quality of C are more important on the rates of BP in the ecosystem with the highest humic carbon concentrations, while in ecosystems with low DOC, these two factors play weak or no influence on BP. Given the current events of eutrophication and climate change, a reduction in the activity of bacterial communities in aquatic ecosystems would be expected, with consequences for the entire food web. The present results point out that factors like substrate quality and ix the structure of the bacterial community deserve special attention in future studies for a better understanding of the influence of temperature and nutrient on BP in humic tropical aquatic ecosystems.
244

Aplicação de modelos (ASSETS e TRIX) para avaliação do estado trófico e cenário futuro da eutrofização do complexo estuarino - lagunar Mundaú - Manguaba, (AL)

Cotovicz Junior, Luiz Carlos 28 June 2017 (has links)
Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-06-28T15:37:27Z No. of bitstreams: 1 Luiz Carlos Cotovicz Junior Dissertação de Mestrado.pdf: 2558658 bytes, checksum: 1d54796a7a49a989f920bff8f781050e (MD5) / Made available in DSpace on 2017-06-28T15:37:27Z (GMT). No. of bitstreams: 1 Luiz Carlos Cotovicz Junior Dissertação de Mestrado.pdf: 2558658 bytes, checksum: 1d54796a7a49a989f920bff8f781050e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ / O Complexo Estuarino Lagunar de Mundaú - Manguaba (CELMM), Alagoas, vem sof rendo grande pressão antrópica ao longo de suas margens e bacias de drenagens. Efluentes agrícolas provenientes da atividade sucroalcooleira, e efluentes urbanos oriundos da densa ocupação urbana são despejados para dentro das lagunas , sem tratamento prévi o, desencadeando o processo da eutrofização . A eutrofização cultural é considerada um dos maiores problemas ambientais a nível mundial. Ao longo das últimas 5 décadas, diversas abordagens tem sido propostas para avaliar o estado trófico e os processos envo lvendo a eutrofização, destacando - se os modelos multiparamétricos ASSETS ( Assessment of Estuarine Trophic Status ) e TRIX ( Trophic Index ). O modelo ASSETS consiste na combinação de indicadores de pressão, estado e resposta (PER). O modelo TRIX avalia indica dores de pressão e distúrbio ambiental, estabelecendo um índice de estado trófico. A essência desse projeto foi a definição do estado trófico e a avaliação do processo da eutrofização no CELMM através da aplicação das metodologias ASSETS e TRIX, de modo a promover classificações do sistema baseadas em escalas temporais e espaciais. Os estudos foram conduzido s em três etapas: 1) avaliação do comportamento dos principais parâmetros físico - químicos relacionados com a problemática da eutrofização; 2) estabeleci mento dos indicad ores de PER pela metodologia ASSETS; 3) estabelecimento do estado trófico mediante aplicação do índice TRIX. Os dados foram coletados em 7 campanhas amostrais, entre 2006 e 2009, no âmbito do Projeto POLCAMAR. O sistema apresentou caracter ísticas sazonais distintas em relação aos parâmetros físico - químicos, principalmente em relação a salinidade que teve menores valores no período chuvoso, associados com as maiores pluviosidades e vazões dos rios. As concentrações de clorofila - a e turbidez tiveram variações entre as coletas, com altos valores em ambos os períodos dentro das lagunas sugerindo alta densidade fitoplanctônica. Os valores de fósforo inorgânico dissolvido (PID) e nitrogênio inorgânico dissolvido (NID) foram variados, sem caráter s azonal definido, com concentrações nas lagunas uma ordem de grandeza superiores a seus canais. O modelo ASSETS mostrou que o sistema é naturalmente susceptível a eutrofização em função das suas características geomorfológicas e hidrológ icas (baixa renovaçã o de água). Os aportes de nutrientes calculados para o CELMM foram altos, associados aos múltiplos usos antropogênicos da s bacia s de drenagem . O estado trófico ASSETS mostrou eutrofização “ moderada ” em Mundaú e “ alta ” em Manguaba . A expectativa futura é um a “ melhora baixa ” nas condições, em função de obras de gerenciamento ambiental e investimentos em saneamento básico previstos para a região. A classificação ASSETS final foi “ pobre ” para Mundaú e “ ruim ” para Manguaba. O índice de estado trófico TRIX calcul ado foi classificado como “ moderado ” (mesotrófico a eutrófico), indicando produção primá ria variando de moderada a alta, com os canais tendo águas menos tróficas que as lagunas. Assim como o estado trófico calculado pelo ASSETS, o TRIX não mostrou diferenç as sazonais de classificação , sugerindo eutrofização constante ao longo dos períodos considerados. Os modelos mostraram resultados satisfatórios através dessas novas abordagens multiparamétricas para o estabelecimento de índices de estado trófico e eutrofi zação. Entretanto são propostas melhorias para os modelos, como a definição de escalas regionais para o índice TRIX e definições mais detalhadas no calculo dos indicadores de pressão e resposta para o modelo ASSETS. Algumas limitações foram identificadas, principalmente em relação à disponibilidade de dados para aplicação dos modelos / The Tropical Coastal Lagoon - Estuarine Complex Mundaú - Manguaba ( CELMM), Alagoas, has been under heavily human pressure over its drainage basins. Agricultural effluents from sugar cane and ethanol activities , and urban effluents from the dense occupation are dumped into the lagoons, untreated, triggering the process of eutrophication. The cultural eutrophication is considered one of the major environmental problems worldwide. Over the past five decades, several approaches have been proposed to assess the trophic state and e utrophication processes , particularly the multiparameter ASSETS (Assessment of Estuarine Trophic Status) and TRIX (Trophic Index) models . The ASSETS approach consists of a combination of indicators of pressure, state and response (PS R). The TRIX index evaluates indicators of environmental pressure and f actors that are direct expressions of productivity , establishing a trophic state index. The essence of this project was to define the trophic state and evaluate the process of eutrophication in CELMM through the application of methodologies ASSETS and TRIX in order to ran k the system based on temporal and spatial scales. The studies were conducted in three stages: 1) evaluation of the behavior of the main physico - chemical parameters related to the eutrophication problem; 2) establishment of PS R indicators by the ASSETS met hodology; 3) establishment of the trophic state index by applying the TRIX. Data were collected from 7 sampling campaigns between 2006 and 2009, under the POLCAMAR Project. The system showed distinct seasonal characteristics in relation to physicochemical parameters, especially in relation to salinity that was lowest during the rainy season, associated with higher rainfall and river flows. Th e concentrations of chlorophyll - a and turbidity were variable between the samples, with high values in both periods a nd inside the lagoons , suggesting high phyt oplankton density. The values of dissolved inorganic phosphorus (PID) and dissolved inorganic nitrogen (NID) were mixed, with no seasonal character set. The lagoons exhibited concentrations one order of magnitude higher than the channel s . The ASSETS model showed that the system is naturally susceptible to eutrophication according to their geomorphological and hydrological characteristics (low water renewal). The calculated n utrient inputs were high for CELMM, assoc iated with the multiple anthropogenic uses in the drainage basins. The ASSETS trophic state showed eutrophication "moderate" in Mundaú and "high" in Manguaba. The future outlook is an "improved low" in the conditions, due to the environmental management wo rks and investments in basic sanitation expected to the region. The final ASSETS classification was "poor" to Mundaú and "bad" for Manguaba. The TRIX index calculated was classified as "moderate" (mesotrophic to eutrophic) in both lagoons , indicating prima ry production ranging from moderate to high, whereas in the channels the classification were good (mesotrophic). The TRIX results indicating that water channels have better trophic state than the lagoons. As calculated by the ASSETS , the TRIX showed no sea sonal differences in classification, suggesting eutrophication constant over the periods considered. The models showed satisfactory results with these new approaches in the establishment of multiparametric indices of trophic state and assessment of eutroph ication. However , improvements are proposed for the models, such as setting regional scales for the TRIX index and more detailed definitions in the calculation of pressure and re sponse indicators for the ASSETS model . Some limitations were identified, main ly related to the availability of data set for application of the indices
245

Contribution à l'étude des successions écologiques du phytoplancton dans la lagune de Ghar El Melh / Contribution to the study of ecological successions of the phytoplankton in the lagoon of Ghar El Melh

Dhib, Amel 20 July 2015 (has links)
Il s’agit de l’étude des successions écologiques du phytoplancton dans la lagune de Ghar El Melh au niveau de 5 stations pendant (i) un suivi bimensuel allant du janvier 2011 à janvier 2012 et (ii) un suivi saisonnier à partir du novembre 2012 à mars 2013. L’étude écologique a été consacrée au microphytoplancton en relation avec les facteurs abiotiques (température, salinité et nutriments) et biotiques (microalgues épiphytes, kystes des dinoflagellés, ultraplancton et ciliés). L’analyse hydrologique du milieu a montré une variation principalement saisonnière de la plupart des paramètres avec des valeurs élevées de la température et de la salinité en été et des concentrations exceptionnelles des nutriments en automne et en hiver. Le phytoplancton de la lagune de Ghar El Melh a été principalement dominé par les dinoflagellés et les diatomées avec une manifestation alarmante des espèces nuisibles atteignant plus que 70 % du peuplement. Ces proliférations ont été remarquées durant toute l’année avec une manifestation plus marquante dans les régions internes de la lagune ce qui est principalement tributaire à la température de l’eau, l’azote total, le nitrogène et l’orthophosphate. Une importante contribution des espèces épiphytes au phytoplancton a été signalée notamment celle du dinoflagellé toxique Prorocentrum lima. L’inventaire spécifique du phytoplancton dominé par l’espèce Prorocentrum micans (> 28 %) et d’autres espèces ne produisant pas de kyste a été en concordance avec les faibles valeurs enregistrées pour les kystes de dinoflagellés dans le sédiment où le maximum enregistré a été de l’ordre de 229 kystes g-1. Une part importante de l’ultraplancton a été représentée par le nanophytoplancton et les hétérotrophes procaryotes, dépassant largement les concentrations microphytoplanctoniques, ce qui est un indice de l’eutrophisation du milieu. Des corrélations hautement significatives ont été trouvées entre le microphytoplancton et les organismes microzooplanctoniques évoquant un probable rôle de ces derniers dans le contrôle des proliférations microalguales nuisibles. / We explored the distribution of the microphytoplankton community in relation to both abiotic (temperature, salinity and nutrients) and biotic factors (epiphytes microalgae, dinoflagellate cysts, ultraplankton and ciliates) in Ghar al Melh Lagoon at 5 stations during (i) a biweekly sampling from January 2011 to January 2012 and (ii) a seasonal sampling from november 2012 to march 2013. The results pointed out a seasonal variation of all parameters with high water temperature and salinity in summer and exceptional concentrations of nutrients in autumn and winter. Microphytoplankton was mainly dominated by dinoflagellates and diatoms with sequences of harmful species proliferation attaining more than 70 % of total phytoplankton. These sporadic proliferations occurred throughout the year with exacerbation in the inner parts of the lagoon mainly related to temperature and total nitrogen, nitrogen and orthophosphate. An important contribution of epiphytic species to phytoplankton abundance was recorded with especially the presence of the toxic dinoflagellate Prorocentrum lima. Microphytoplankton was dominated by Prorocentrum micans (> 28 %) and other non-cyst former species consistent with the low dinoflagellate cysts found at sediment surface (maximum = 229 cysts g-1 DS). Urtraplankton was chiefly represented by nanophytoplankton and heterotrophic prokaryotes, with low microphytoplanktonic abundance. This indicates that the lagoon is undergoing eutrophication. Significant correlations were reported between phytoplankton and microzooplankton suggesting a potential role of the former in controlling harmful microalgae proliferations.
246

Etude de la pollution marine par les hydrocarbures et caractérisation de leurs effets biochimiques et moléculaires sur la palourde de Ruditapes sp. / Study of the marine pollution by hydrocarbons and characterization of their biochemical and molecular effects on clam Ruditapes sp.

Chalghmi, Houssem 06 October 2015 (has links)
Dans notre étude, la biosurveillance de la lagune de Tunis a été réalisée durant une année enemployant une approche combinant les analyses chimiques et biologiques et en utilisant lapalourde Ruditapes decussatus comme espèce bioindicatrice. Cette approche a permis demettre en évidence la forte contamination de la lagune de Tunis par les métaux traces et leshydrocarbures aromatiques polycycliques (HAPs). La variation saisonnière des niveaux debioaccumulation de ces contaminant par la palourde s’avère être fortement associée auxchangements des paramètres physico-chimiques du milieu et aux processus physiologiques del’animal. L’étude de la réponse biologique basée sur l’utilisation d’une batterie debiomarqueurs d’exposition et d’effet situés à différents niveaux de l’organisation biologique :moléculaire (l’expression de cinq gènes d’intérêt), biochimique (les activités benzo(a)pyrènehydroxylase, glutathion S-transférase, acétylcholinestérase, catalase et taux demalondialdéhyde) et tissulaire (altérations histopathologiques), a permis de mettre enévidence une modulation des processus de défense contre les perturbations induites par lapollution et l’identification des altérations histopathologiques (structurales) au niveau desbranchies et de la glande digestive impliquant un impact sévère des contaminants sur l’état desanté de la palourde. L’étude des interactions spatio-temporelles entre les facteurs abiotiqueset biotiques a permis d’identifier la température et la reproduction comme paramètresprincipaux affectant la réponse biochimique de défense et d’effet. L’analyse en composanteprincipale (ACP), regroupant tous les paramètres analysés pendant le printemps, nous apermis d’identifié le site Z2 comme le site le plus affecté par la pollution. Dans un secondtemps, le benzo(a)pyrène (BaP), déjà identifié dans la lagune de Tunis, a été employé dansdes conditions contrôlées au laboratoire afin de caractériser les réponses moléculaires etbiochimiques chez les bivalves (Ruditapes philippinarum et Crassostrea gigas) face à desexpositions subaiguës et aiguës à ce contaminant. Cette étude nous a permis d’identifier unemodulation des biomarqueurs biochimiques de métabolisation, de stress oxydant et deneurotoxicité et de l’expression des gènes impliqués dans les processus de métabolisation, derespiration mitochondriale, de défense antioxydante, de reproduction et de défenseimmunitaire. L’analyse de l’altération de l’ADN a révélé un pouvoir génotoxique précoce etélevé du BaP chez les deux bivalves. / Firstly, biomonitoring of Tunis lagoon was conducted during one year using an approach combining chemicals and biological analyses and the bioindicator species Ruditapesdecussatus. This approach high lighted the high contamination of the Tunis lagoon by tracemetals and polycyclic aromatic hydrocarbons (PAHs). Seasonal variation of contaminant bioaccumulation levels in clam was found to be strongly associated with physico chemical changes in surrounding environment and physiological processes in organism. Biological responses investigated through a battery of exposure and effect biomarkers located at differentlevels of biological organisation: molecular (expression of five genes), biochemical(benzo(a)pyrene hydroxylase, glutathione S-transferase, acetylcholinesterase and catalase activities and malondialdehyde concentration) and tissular (histopathological damages),demonstrated a defense process modulation by pollution and showed histopathological alterations in gills and digestive gland involving severe impact of contaminants on health stateof clam. The study of spatio temporal interactions between abiotic and biotic factors identified temperature and reproduction as main parameters affecting defense and effect biochemical response. The principal component analysis (PCA), using all analyzed parameters during thespring, allowed to identify site Z2 as the most affected by pollution. Secondly,benzo(a)pyrene (BaP), already identified in Tunis lagoon, was used in controlled conditions at the laboratory in order to characterize the molecular and biochemical responses in bivalves(Ruditapes philippinarum and Crassostrea gigas) facing a subacute and acute exposures tothis contaminant. This study showed a modulation of biochemical biomarkers of metabolism,oxidative stress and neurotoxicity and expression of genes involved in process of metabolisation, mitochondrial respiration, antioxidant defense, reproduction and immune defense. The analysis of DNA damages revealed a high and early genotoxicity effect of BaPin both bivalves.
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A method for imputing economic value to ecological goods and services provided by the Knysna River

Saunders, James Woodward January 2008 (has links)
The purpose of this thesis was to develop a method by which economic value can be imputed from an economic activity to a non-market ecological function or service which contributes to that economic activity. The Knysna River in South Africa was chosen as the ecological function which supported three economic activities from which value was to be imputed; these were the Knysna Municipal Water Supply, Fish Production in the Knysna Estuary and Production of Indigenous Forest within the Knysna Catchment. Three underlying assumptions and two functional operations were required in order to implement the suggested method. The underlying assumptions were: - The ecological and economic activities considered are within a single catchment. - The allocation of value imputed for a specific economic activity to the ecological function or service under consideration (in this case the Knysna River) is proportional to the total contribution of ecological functions or services contributed to the economic activity. - The valuation of the economic activity for the purposes of obtaining a price-quantity point on a demand function is to be full cost pricing with no producer surplus. The two functional requirements were: - Diagram or map the linkages between an economic activity and the supporting ecological functions. - Determine the consumer surplus related to an incremental change in quantity under a demand function where the original price and quantity are known. A value from each of the economic activities was imputed to the Knysna River. However, the method was not tested. Nonetheless applying the equations and collecting the required data allowed several methodological needs to be clearly pointed out. The most acute deficiency was difficulty in obtaining secondary data from governmental agencies, commercial representatives and existing published academic research to ensure a robust price. Also, scientific information was not sufficiently available for allocating ecological contributions to the economic activities. Even with the shortage of credible data the method appears to allow non-market ecological functions to be valued in context of an existing economic system.
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Navegação hidroviária interior no RS : vantagem econômica comparada aos outros modais e implantação do calado sazonal

Cunha, Gilberto Teixeira da January 2014 (has links)
O Rio Grande do Sul possui um grande potencial para a navegação interior devido à extensão de sua rede hidrográfica de quase 2200 km, sendo 930 km navegáveis. Aliado a isto, na última década o estado apresentou um crescimento econômico em relação ao Produto Interno Bruto (PIB) de 167,2 %, segundo a Fundação de Economia e Estatística/RS. Mesmo com estas condicionantes favoráveis constata-se que o modelo atual da estrutura logística da movimentação de cargas continua a não privilegiar o setor hidroviário interior. Tendo em vista estes aspectos, esta dissertação apresenta um estudo cujos objetivos são: (i) identificar a representatividade do modal hidroviário interior em relação à movimentação de cargas, destinadas à exportação e importação, da metade norte do Rio Grande do Sul aos principais terminais privados hidroviários e ao porto público, localizados na cidade de Rio Grande; (ii) comparar o modal hidroviário com seus principais concorrentes, os modais rodoviário e ferroviário e (iii) avaliar o impacto econômico da adoção do calado sazonal. Para a comparação dos modais foram escolhidos três parâmetros que estabelecem custos em relação à tonelada quilometro transportada, são eles: custo médio de operação; custo despendido com combustíveis; e custos sociais. Após as informações coletadas foram processadas e analisadas, possibilitando identificar os custos gerados por cada modal. Na comparação destaca-se que o custo dos modais rodoviário e ferroviário são respectivamente 1541% e 405% maior do que o hidroviário interior e que a carga movimentada pelos três modais, em 2011, representou um custo total de R$ 1,79 bilhões, ou seja, 0,65% do PIB estadual. Na avaliação da adoção do calado sazonal foi estudado o possível ganho em termos de capacidade de transporte de cargas e a redução de custos gerada pela utilização do transporte hidroviário interior, no Rio Grande do Sul, decorrentes da possível implantação da permissividade de um calado sazonal, em função da variação histórica dos níveis de água, verificados através das curvas de permanências em nove estações pluviométricas localizadas na Laguna dos Patos e no Lago Guaíba. Constatou-se que a adoção do calado sazonal, no ano de 2011, teria um impacto de redução de custos de transporte na ordem de R$ 40,7 milhões, considerando a migração do modal rodoviário para o hidroviário e de R$ 10,1 milhões se fosse considerado a migração do modal ferroviário para o hidroviário. / The state of Rio Grande do Sul (RS), in Brazil, has a significant potential for internal navigation due to the extent of its drainage network of almost 2,200 km, of which 930 km are navigable. Allied to this, in the last decade the state had an economic growth in relation to Gross Domestic Product (GDP) of 167.2%, according to the Foundation of Economics and Statistics/RS. Even with these favorable conditions it appears that the current model of logistic structure of shipment continues to not emphasis on the internal waterway sector. Considering these aspects, this dissertation presents a study whose objectives are: (i) identify the representativeness of the interior waterways in relation to handling, for export and import, the northern half of Rio Grande do Sul to the main private terminals waterway and the public port, located in the city of Rio Grande , (ii) compare the waterways with its main competitors, the road and rail modes, and (iii) evaluate the economic impact of the adoption of the draft season. To compare the modals, three parameters that establish costs in relation to the tone kilometers transported were chosen, they are: average cost of operation, cost spent on fuel, and social costs. After the data were processed and analyzed, it was possible to identify the costs generated by each mode. In comparison it is emphasized that the cost of road and rail modes are respectively 405% and 1541% higher than the inland waterway and the shipment handled by the three modes, in 2011, represented a total cost of R$1.79 billion, i.e. 0.65% of the state GDP. In assessing the adoption of the draft seasonal possible gain was studied in terms of load carrying capacity and reducing costs generated by the use of inland waterway transport, in Rio Grande do Sul, from the possible deployment of the permittivity of a quiet season in function of the historical variation in water levels, checked through the curves stays in nine rainfall stations located in the Patos Lagoon and Lake Guaiba. It was found that the adoption of the draft season , in 2011, would have an impact of reducing transport costs in the order of R$40.7 million, considering the migration from road transport to waterways and R$10.1 million if found migrating the railroad to the waterway.
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Estudo da pesca artesanal em dois setores do complexo estuarino-lagunar de Cananéia-Iguape (SP) considerando relações sócio-ambientais / Study of the artisanal fishery in two sectors of Cananéia-Iguape estuarine-lagoon complex considering socio-environmental factors.

Esther Nespoli de Oliveira 14 September 2011 (has links)
Este trabalho tem como objeto de estudo, a relação entre fatores sócio-ambientais e a pesca artesanal nos setores norte (Iguape) e sul (Cananéia) do Complexo Estuarino-Lagunar de Cananéia-Iguape (SP), considerando as mudanças hidroquímicas provocadas pela água que adentra o sistema através Valo Grande, um canal artificial que drena parte água do Rio Ribeira de Iguape para o Mar Pequeno, junto ao município de Iguape. Os parâmetros hidrológicos abordados foram: penetração de luz, temperatura, salinidade, oxigênio dissolvido, pH, MPS e nutrientes dissolvidos obtidos em diferentes profundidades. Os dados relativos à atividade pesqueira e perfil social dos pescadores foram obtidos por meio de entrevista semi-estruturada, com perguntas fechadas e abertas junto às comunidades caiçaras de Cananéia e Iguape. Os resultados ambientais mostraram diferenças hidrológicas importantes entre os dois setores, com baixa salinidade no setor norte, sob maior influência do canal do Valo Grande, enquanto a porção sul preserva as características estuarinas, porém sinais da interferência do setor norte já estão sendo sinalizados no sul, o que pode ser verificado junto a dados pretéritos do corpo hídrico. As espécies alvo de pesca encontradas nos dois setores do sistema também indicaram as alterações ambientais, mostrando características locais e variações sazonais. Foi verificado que os pescadores adaptaram-se às modificações ambientais, alternando as artes de pesca ao longo do ano e, investindo em embarcações, motores e petrechos de pesca, dando continuidade à atividade. Avaliando-se o perfil dos pescadores urbanos, foram verificadas condições sócio-econômicas que permitem viii que a maioria de suas residências seja de alvenaria, dispondo de abastecimento de água e energia provenientes da rede pública, porém a maioria dos entrevistados interromperam seus estudos. Este estudo evidenciou a dificuldade dos pescadores em ter o sustento somente da atividade pesqueira praticada, comprometendo assim, a sobrevivência desta tradição, e desestimulando o desenvolvimento deste setor. Esta situação também leva ao registro de um perfil diferenciado de caiçara, marcado pelo desempenho de outras atividades além da pesca. Assim, foi possível observar que diante de mudanças, extremas ou não, o comportamento humano estará sempre interligado ao ambiental, os quais estão em constante renovação, caracterizando a cultura de gerações. A economia solidária estabelecida por meio de uma cooperativa, ou de ações apoiadas por políticas públicas, constituem alternativas que contribuem à solução de alguns problemas que afetam as comunidades estudadas. Certamente, ações participativas que insiram o pescador nos projetos gestão e preservação ambiental, permitindo uma maior atuação junto às políticas públicas locais, contribuirão à sustentabilidade ambiental, sócio-cultural e econômica. / This work aims to study the relations between socio-environmental factors and the artisanal fishery in the sectors north (Iguape) and south (Cananéia) of the Cananéia-Iguape Estuarine-Lagoon Complex, considering the hydrochemical changes caused by the water that enters within the system through Valo Grande, an artificial channel that drains part of the Ribeira de Iguape River waters to Mar Pequeno, Iguape. The hydrological parameters studied were: penetration of light, temperature, salinity, dissolved oxygen, pH, suspended particulate matter and dissolved nutrients obtained in different depths. The data concerning the fishery activities and social profile of the fishermen were obtained through semi-structured interviews, with closed and open questions made with the communities of Cananéia and Iguape. The environmental results showed important hydrological differences between the two sectors, with low salinity in the northern sector, under greater influence of Valo Grande Channel, while the southern sector still preserves estuarine characteristics. However, signals of the north interference are already being noticed in the south, this can be verified by comparing past data of the water body. The fishery target species found in the two sectors of the system also pointed to environmental changes, showing local characteristics and seasonal variations. It was verified that the fishermen adapted to the environmental changes by changing the fishery type throughout the year and investing in boats, engines and fishery equipment, this way continuing with the activity. Socio-economical conditions that allow most of the residences to be made of masonry, having energy and water supplied by the public services, were verified evaluating the fishermen profile. However most of the fishermen had their formal education interrupted. This study shows the difficulty of the fishermen to have their livelihood only by fishing, therefore compromising the survival of this tradition and discouraging the development of this sector. This situation also leads to register a differentiated fishermen profile, marked by the realization of other activities besides fishery. So, it was possible to observe that faced with changes, extremes or not, the human behavior will always be linked to the environment, they are in constant renovation, x characterizing the culture of generations. The solidarity economy established by a cooperative or by actions supported by public politics constitutes alternatives that contribute to the solution of some problems that affect this community. Certainly, participative actions, that insert the fishermen in management and environmental preservation projects, allowing a greater participation in local public policies, will contribute to the environmental, socio-cultural and economic sustainability.
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Classifying and Mapping Diversity in a Species-Poor System: The Mangrove Meta-Community of Laguna Chacahua National Park, Oaxaca, Mexico

Weisgerber, Elizabeth Kay 01 September 2011 (has links) (PDF)
ABSTRACT Classifying and Mapping Diversity in a Species-Poor System: the mangrove meta-community of Laguna Chacahua National Park, Oaxaca, Mexico by Elizabeth Kay Weisgerber Both field transects and imagery grid plots were analyzed with the goal of creating a community classification map for the mangrove forest of Parque Nacional Lagunas de Chacahua. In total, data was collected in 49 sites throughout the park, recording measures such as DBH, basal area, estimated dominance, frequency, cover and relative dominance. Field locations were marked and georeferenced with a GPS and grid plots overlaid on satellite imagery of the park were generated via a random number table. Species' attributes delineating the identifiable features for each dominant species within Chacahua were noted and used to recognize patterns in species assemblages. Fourteen distinct ‘sub-communities’ within the mangrove meta-community were recognized using this data and verified with 165 field photos. Relative dominance values were compared between field and grid data. These data revealed a similar pattern with Rhizophora mangle being most dominant under each method. Avicennia germinans was second in relative dominance, Laguncularia racemosa a close third while Conocarpus erectus was rarely found, most likely due to over-harvesting. Rapid degradation of mangrove forests is occurring on a global scale. Understanding the complex dynamics that occur within the mangrove meta-community is essential to its conservation. Vegetation maps are essential tool in monitoring changes throughout the mangrove but are rarely of sufficient detail for everyday use. Generating highly detailed vegetation maps in a cost-effective and timely manner is an important step for their conservation, particularly in developing countries. This study demonstrates methods and techniques for producing a vegetation map that portrays the level of complexity that exists within the species-poor mangrove environment. This map will be donated to the management team of Parque Nacional Lagunas de Chacahua to better aid in management.

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