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Aloformação Paranavaí: depósitos coluviais quaternários da Bacia Hidrográfica do Alto Rio Paraná (SP, PR e MS); Paranavaí alloformation: quaternary colluvial deposits of Upstream Rio Paraná Hydrographic Basin (SP, MS e PR)

Sallun, Alethea Ernandes Martins
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 26/06/2007 PT
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66.42%
Depósitos pleistocênicos arenosos de origem coluvial são encontrados em diversas regiões do Brasil, nos estados de São Paulo, Paraná e Mato Grosso do Sul. Associados a distintos contextos geológicos, esses depósitos têm recebido diferentes denominações como Formação Paranavaí (SP, PR e MS), Formação Piquerobi (SP) e Formação Cachoeirinha (MS). Neste contexto, foi possível individualizar sob pontos de vista sedimentológico, geocronológico e estratigráfico os depósitos quaternários que ocorrem na Bacia Hidrográfica do Alto Rio Paraná (SP, PR e MS) através da aloestratigrafia, propondo formalmente o Alogrupo Alto Rio Paraná, que é constituído de depósitos coluviais da Aloformação Paranavaí e depósitos fluviais da Aloformação Paraná. Os resultados obtidos indicam que o Alto Rio Paraná está ativo, no mínimo desde 1 Ma passados até os dias atuais, no afeiçoamento do relevo de formas construtiva (terraços) e destrutiva (dissecação). Esses registros geológicos testemunhariam importantes mudanças paleoclimáticas e/ou eventos neotectônicos, que modificaram os níveis de base e reafeiçoaram o relevo. Os episódios de agradação coluvial dos depósitos da Aloformação Paranavaí, instalados sobre superfícies peneplanizadas e afeiçoadas durante o Pleistoceno...

O papel dos fluxos evasivos de óxido nitroso no ciclo do N nos rios Negro e Solimões (Amazonas) e na bacia do rio Ji-Paraná (Rondônia); The role of N2O evasive fluxes in the nitrogen cycle at the Negro and Solimões rivers (Amazonas) and the Ji-Paraná river basin

Oliveira, Carolina Barisson Marques de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 15/10/2007 PT
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56.26%
As concentrações do gás óxido nitroso (N2O), um importante agente do efeito estufa, têm aumentado significativamente nos últimos cem anos. As razões para este aumento atmosférico de N2O se encontram parcialmente inexplicadas e esta lacuna ainda é mais grave em relação aos ambientes aquáticos. Este trabalho teve como objetivo quantificar os fluxos de N2O entre a atmosfera e as águas de alguns rios da Bacia Amazônica. As áreas de estudo estão localizadas na Amazônia Brasileira, nos estados de Rondônia e Amazonas. Os rios foram amostrados mensalmente, entre setembro de 2005 e fevereiro de 2006. A água dos rios foi coletada por meio de bombas de imersão, no meio do canal, a 60% da profundidade total, contada a partir da superfície. Para evitar o contato com o ar, as amostras eram colocadas em frascos de 2 L preenchidos com 60 mL de N2 . O método denominado headspace foi utilizado a fim de equilibrar o N2O dissolvido com o N2. Para transporte ao laboratório, 25 mL do gás resultante eram transferidos para dentro de frascos de penicilina selados. Amostras do ar atmosférico foram coletadas cerca de um metro acima da água e estocadas da mesma maneira. As concentrações de N2O foram quantificadas por cromatografia gasosa...

Spatial and temporal distribution of the zoobenthos community during the filling up period of Porto Primavera Reservoir (Paraná River, Brazil)

Jorcin, A.; Nogueira, MG.; Belmont, R.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: 19-29
ENG
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Este estudo é parte do monitoramento limnológico empreendido pela Companhia Energética do Estado de São Paulo (CESP) durante o processo de enchimento do reservatório de Porto Primavera (Usina Hidrelétrica Engenheiro Sérgio Motta). Este reservatório, localizado no alto rio Paraná, entre os Estados de São Paulo e Mato Grosso, é o quarto maior do país. A primeira etapa de enchimento do lago começou em dezembro de 1998 e a segunda em março de 2001. Amostras para a análise da comunidade bentônica e das características sedimentológicas foram coletadas trimestralmente entre agosto de 1999 e novembro de 2001 e também em agosto de 2002 (11 campanhas). As coletas foram feitas em 13 estações de amostragem distribuídas no reservatório e em uma localizada a jusante da barragem. 128 táxons de invertebrados foram encontrados, sendo Mollusca, Annelida, Insecta e Nematoda os grupos dominantes durante praticamente todos os meses analisados. A classe Insecta foi a melhor representada, com 9 diferentes ordens, dentro das quais os Diptera contribuíram com a ocorrência de 63 táxons. A espécie exótica de bivalve Corbicula fluminea foi registrada em todas as estações de amostragem mostrando sua grande capacidade para colonizar novos habitats em regiões neotropicais. Variações consideráveis na densidade da fauna foram observadas para os diferentes períodos e locais analisados. A densidade máxima (média de 7812 ind.m-2) foi registrada no centro do reservatório enquanto que as densidades mínimas foram registradas na zona lacustre próxima à barragem (média de 9 ind.m-2). A maior riqueza de espécies por local/período (24 táxons) foi encontrada no trecho superior do reservatório (trecho fluvial). A diversidade máxima foi observada nas zonas superior e central do reservatório...

Microbial respiration and chemical composition of different sediment fractions in waterbodies of the upper Paraná River floodplain, Brazil

THOMAZ,S. M.; PEREIRA,G.; PAGIORO,T. A.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/05/2001 EN
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66.28%
Four size fractions of the sediment of six environments of the upper Paraná River floodplain were analyzed for carbon, nitrogen, and phosphorus contents and microbial respiration (oxygen consumption). Particle size did not affect nitrogen and phosphorus content or microbial activity, but did affect carbon content (F = 4.274, df = 3; 20, p = 0.020). The carbon concentration of ultra-fine particles was significantly lower than that of other sizes of sediment particles. Microbial respiration values were well predicted by sediment chemical composition, as shown by multiple regression (microbial respiration = -0.39 - 0.210C + 0.108N + 0.796P; F = 7.0495, p = 0.0022). However, phosphorus was the element which best explained the microbial respiration (partial coefficient = 0.796, p = 0.0039, n = 23). Considering that i) phosphorus was the best predictor of microbial respiration; ii) phosphorus is trapped in the series of reservoirs located upstream from the section of the floodplain studied; and iii) microbial respiration is a measure of decomposition rates and nutrient cycling, we hypothesize that the long-term accumulation of litter detritus and reduction of nutrient cycling in environments of the upper Paraná River floodplain are probable impacts of this decrease in phosphorus caused by the upstream reservoirs.

Colonização ictiofaunística do Reservatório de Itaipu e áreas adjacentes

Benedito Cecilio,Evanilde; Agostinho,Angelo Antonio; Júlio Jr,Horácio Ferreira; Pavanelli,Carla Simone
Fonte: Sociedade Brasileira de Zoologia Publicador: Sociedade Brasileira de Zoologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/1997 PT
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Samples were taken from November 1983 to October 1989 in sites along the main body of the Itaipu reservoir and its area of influence to evaluate the impacts of this reservoir on ichthyofauna and to provide information about the colonization process in the dammed area. The ichthyofaunistic similarity between the sites was analysed during the studied period. Spatial and temporal variations of the ichthyofaunistic diversity were also done, using Shannon-Winer Index of Diversity, eveness and species richness, comparing the results with those obtained before the damming. After Itaipu Reservoir formation, it was observed significative alteration in specific abundance and ichthyofauna structure of the Paraná River, with an increase in species number in ali tributaries of the reservoir, and a high replacement in species. Diversity and species richness were higher in the dammed stretch of the Paraná river and in its tributaries of the left side after the Itaipu reservoir formation. Among the sampled sites, the highest values of the diversity index were registered in Paraná River upstream and downstream the reservoir, Iguatemi river and Arroio Guaçu. Based on information of similarity in species composition and abundance in the sampled area...

Feeding of Acestrorhynchus lacustris (Characidae): a post impoundment studies on Itaipu reservoir, upper Paraná River, PR

Hahn,Norma Segatti; Delariva,Rosilene Luciana; Loureiro,Valdirene Esgarbosa
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2000 EN
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66.06%
With objective to know feeding spectrum of Acestrorhynchus lacustris (Reinhardt, 1874), a middle size predator in different places of influence area of Itaipu reservoir, stomach contents were analyzed. Samples were collected from March 1984 to February 1989 from Itaipu Reservoir and its adjacent areas. Its fed mainly on fishes, but it was an opportunistic (consumed 17 species of prey). Despite of the wide feeding spectrum, few preys were dominant in the diet, according to the different habitats sampled. As a result, it significant spatial differences in the diet was observed. Was observed through "Detrented Correspondence Analysis" (DCA) these were divided into three groups in relation with diet: preys from upstream, with higher scores; preys from the reservoir, with intermediate scores; and preys from a tributary with smaller scores. This discrimination may be a function of prey availability in each habitat. The mean size of preys consumed increased with the size of the predator, as well as the variance, i. e. the largest fish also consumed small preys.

Interannual variability of phytoplankton in the main rivers of the Upper Paraná River floodplain, Brazil: influence of upstream reservoirs

Rodrigues,LC.; Train,S.; Bovo-Scomparin,VM.; Jati,S.; Borsalli,CCJ.; Marengoni,E.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
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66.4%
The interannual variation of phytoplankton communities in the three main rivers of the Upper Paraná River floodplain is evaluated in relation to changes in the hydrosedimentological regime. These changes are a result of climatic variability and the formation of Porto Primavera Reservoir, located at the upper Paraná River. Phytoplankton species richness and density were investigated in rivers during a prior period (1993-1994) and eight years after reservoir impoundment (2000-2007). Multiple analyses were conducted to test the differences between these time periods in order to find predictor variables for phytoplankton attributes. A total of 454 phytoplanktonic taxa were found. The regression analysis revealed significant differences between periods. In the years following construction of the Porto Primavera dam, species richness was lower in the Paraná River and density was higher in the three rivers. In general, the algal density decreased from 2005 to 2007. Diatoms and cyanobacteria contributed significantly to the total density during the period from March 1993 to February 1994. The years 2000-2007 presented the lowest diatom contribution to species richness and the highest cyanobacteria contribution. From 2000 on, cryptomonads and cyanobacteria dominated. The interannual variability of phytoplankton was probably influenced by changes in hydrosedimentological regime due to climatic variations (La Niña and El Niño - Southern Oscillation events - ENSO) and the operational procedures associated with an upstream reservoirs. Studies on climatic variability and its effects on hydrosedimentological regimes of the Paraná...

Consequences of dam construction upstream of the Upper Paraná River floodplain (Brazil): a temporal analysis of the Chironomidae community over an eight-year period

Rosin,GC.; Oliveira-Mangarotti,DP.; Takeda,AM.; Butakka,CMM.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
Relevância na Pesquisa
46.25%
Our study aimed to identify patterns of temporal variation and changes in the structure of the community of Chironomidae larvae in two rivers in the Upper Paraná River floodplain after the construction of a reservoir upstream (Porto Primavera). Samples were taken with a Petersen grab, and were obtained between 2000 and 2007. Chironomidae larvae were identified down to the lowest taxonomic level possible. The high richness of Chironomidae observed in the Paraná and Ivinhema Rivers (100 morphospecies) in comparison to the world average of rivers of the same size (44 species) emphasizes the importance of these habitats for the maintenance of biodiversity. The composition and density of Chironomidae in the years 2000 and 2001 differed from the other years. This period was characterized by extreme changes in the Paraná River flow caused by the closing of the Porto Primavera Dam, which added to a severe dry period in late 2001. The different compositions of morphospecies and the higher similarities in subsequent years are indicative of the recovery and adaptation of the community. In spite of the changes in the composition of morphospecies, diversity was maintained and the community continued to respond to fluctuations in the hydrometric level.

Inter-annual variations in the abundance of young-of-the-year of migratory fishes in the Upper Paraná River floodplain: relations with hydrographic attributes

Suzuki,HI.; Agostinho,AA.; Bailly,D.; Gimenes,MF.; Júlio-Junior,HF.; Gomes,LC.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
Relevância na Pesquisa
66.23%
In this study, we identified and characterized the hydrographic attributes related to the success of recruitment of migratory fishes in the Upper Paraná River floodplain. To achieve our objectives, we analyzed inter-annual variations in the abundance of young-of-the-year (YOY; index of recruitment) of six migratory species and their relations with hydrographic attributes. Recruitment was related to the intensity, duration (in different fluviometrical levels), elasticity, number of pulses, greater uninterrupted overflow and delay of the floods (all obtained using the PULSO software). Collections of fish were conducted in the period between January 1987 and November 2007 in distinct environments (river channels, secondary channels and connected and disconnected floodplain lakes) distributed along three subsystems (Paraná, Baía and Ivinheima). Relations between recruitment and the attributes of interest were determined through analysis of covariance. In the studied period, the highest abundances of YOY were registered in 2007, followed by 1992, 1993, 2005 and 1988. The abundance of YOY was positively correlated with an intensity of high water levels (potamophase) and the duration of potamophase 1 and negatively with the duration of low water levels (limnophase) and a delay of flood. Higher hydrometric levels (540 and 610 cm for Paraná and 325 and 450 cm for Ivinheima) and greatest uninterrupted overflow presented different relations (significant interactions) among subsystems...

Genetic divergence between Pseudoplatystoma corruscans and Pseudoplatystoma reticulatum (Siluriformes: Pimelodidae) in the Paraná River Basin

Bignotto,TS.; Prioli,AJ.; Prioli,SMAP.; Maniglia,TC.; Boni,TA.; Lucio,LC.; Gomes,VN.; Prioli,RA.; Oliveira,AV.; Júlio-Junior,HF.; Prioli,LM.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
Relevância na Pesquisa
66.23%
Pseudoplatystoma corruscans (Spix and Agassiz, 1829) and Pseudoplatystoma reticulatum (Eingenmann and Eigenmann, 1889) are large migratory catfishes of high biological importance and great commercial value in South America. Because fertile crossbreeds can be artificially produced in hatcheries, a high genetic proximity between these two Pimelodidae species is conceivable. Possible escape of crossbred specimens from pisciculture stations is a serious environmental concern. Despite their importance, knowledge of P. corruscans and P. reticulatum biology, ecology, population diversity and genetics is limited. In the present work, the genetic divergence between P. corruscans and P. reticulatum populations from the Paraná River Basin was analyzed on the basis of polymorphisms in ISSR fragments and in the hypervariable sequence of the mitochondrial DNA (mtDNA) control region. Estimates of intraspecific haplotype (h > 0.5) and nucleotide diversities (π < 0.01) indicate that P. corruscans and P. reticulatum have survived a historical population decline, followed by a demographic expansion. The interspecific polymorphisms within the mtDNA control region and ISSR fragments were suitable as diagnostic molecular markers and could be used to discriminate the two species. A unique Pseudoplatystoma specimen...

Limnology in the Upper Paraná River floodplain: large-scale spatial and temporal patterns, and the influence of reservoirs

Roberto,MC.; Santana,NF.; Thomaz,SM.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
Relevância na Pesquisa
46.15%
Knowledge of abiotic limnological factors is important to monitor changes caused by humans, and to explain the structure and dynamics of populations and communities in a variety of inland water ecosystems. In this study, we used a long term data-set (eight years) collected in 10 habitats with different features (river channels, and connected and isolated lakes) to describe the spatial and temporal patterns of some of the principal limnological factors. In general, the degree of connectivity of the lakes, together with the rivers to which the lakes are connected, were important determinants of their limnological characteristics. These differences are expected, because rivers entering the floodplain come from different geological regions and are subject to different human impacts. At large spatial scales, these differences contribute to the increased habitat diversity of the floodplain and thus to its high biodiversity. With regard to temporal variation, Secchi-disk transparency increased, and total phosphorus decreased in the Paraná River main channel during the last 20 years. Although these changes are directly attributed to the several reservoir cascades located upstream, the closing of the Porto Primavera dam in 1998 enhanced this effect. The increase in water transparency explains biotic changes within the floodplain. The lower-phosphorus Paraná River water probably dilutes concentrations of this element in the floodplain waterbodies during major floods...

Blockage of migration routes by dam construction: can migratory fish find alternative routes?

Antonio,Rosimeire Ribeiro; Agostinho,Angelo Antonio; Pelicice,Fernando Mayer; Bailly,Dayani; Okada,Edson Kioshi; Dias,João Henrique Pinheiro
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2007 EN
Relevância na Pesquisa
46.21%
The present study explored the interaction between the upriver migration of fish and the blockage of their migration routes by dam construction. Specifically, we studied (i) the capacity of migratory fish to locate alternative routes in the presence of an obstacle, and (ii) the behavior of the fish after they were artificially transferred to the reservoir. With the use of the mark-recapture technique (tagging), the study was carried out near Porto Primavera Dam (UHE Engenheiro Sérgio Motta) between 1994 and 1999, a period prior to the closure of the floodgates and the installation and operation of the fish pass facilities. The fish were caught in the dam forebay downstream, marked with LEA type tags, and released upstream (5113 individuals; 14 species) and downstream (1491; 12) from the dam. The recaptures were carried out by local professional and amateur fishermen. A total of 188 individuals (2.8%) were recaptured, mostly the curimba Prochilodus lineatus. Nearly half of the recaptures downstream occurred in tributaries, especially in the Paranapanema River, indicating that in the presence of an obstacle the fish are able to locate alternative migration routes. The remainder stayed in the main channel of the Paraná River, at a mean distance of less than 50 km from the release point. Of the fish released upriver from the dam...

A barrier to upstream migration in the fish passage of Itaipu Dam (Canal da Piracema), Paraná River basin

Fontes Júnior,Hélio Martins; Castro-Santos,Theodore; Makrakis,Sergio; Gomes,Luiz Carlos; Latini,João Dirço
Fonte: Sociedade Brasileira de Ictiologia Publicador: Sociedade Brasileira de Ictiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2012 EN
Relevância na Pesquisa
46.28%
The majority of the fish passages built in the Neotropical region are characterised by low efficiency and high selectivity; in many cases, the benefits to fish populations are uncertain. Studies conducted in the Canal da Piracema at Itaipu dam on the Parana River indicate that the system component designated as the Discharge channel in the Bela Vista River (herein named Canal de deságue no rio Bela Vista or CABV), a 200 m long technical section, was the main barrier to the upstream migration. The aim of this study was to evaluate the degree of restriction imposed by the CABV on upstream movements of Prochilodus lineatus and Leporinus elongatus, Characiformes. Fish were tagged with passive integrated transponders (PIT tags) and released both downstream and upstream of this critical section. Individuals of both species released downstream of the CABV took much more time to reach the upper end of the system (43.6 days vs. 15.9 days), and passed in much lower proportions (18% vs. 60.8%) than those tagged upstream of this component. Although more work is needed to differentiate between fishway effects and natural variation in migratory motivation, the results clearly demonstrate passage problems at the CABV.

Hydrological stress as a limiting factor of the invasion of Limnoperna fortunei (Dunker, 1857) in the Upper Paraná River (Brazil)

Campos,Mônica de Cássia Souza; Lanzer,Rosane; Castro,Paulo de Tarso
Fonte: Associação Brasileira de Limnologia Publicador: Associação Brasileira de Limnologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2012 EN
Relevância na Pesquisa
66.26%
Limnoperna fortunei (Dunker, 1857), is an asiatic mussel that arrived in South America in 1991. Since 2004, we have noticed that the advance of this species in the lower Paranaíba River, a tributary of the Upper Paraná River, is slow when compared to the average speed of 240 km/year in the Paraná River (middle and lower course). AIM: The goal of this work is to understand what factors are limiting the spread of L. fortunei in this stretch of the Paranaíba River. METHODS: Its occurrence and dispersion were sampled twelve times between March 2006 and November 2007 in the Paranaíba River, including the São Simão hydroelectric reservoir. Physicochemical characteristics of the water were analysed, and a Stream Length-Gradient Index calculated for the study area. RESULTS: Adult mussels were easily found attached to the hulls of barges that travel on this stretch of the Paraná-Tietê waterway and on vessels that were docked in the harbours of grain exporters located in São Simão (GO). However, no larvae or adults were found near the harbours or upstream from them at the São Simão hydroelectric reservoir. The pH and concentration of calcium and dissolved oxygen values among lotic habitats and the reservoir were similar: DO values were close to 7 mg.L-1...

Ocorrência e dieta da lontra neotropical, Lontra longicaudis (Olfers, 1818), em dois rios do Parque Nacional de Saint-Hilaire/Lange, Serra da Prata, Paraná

Navarro, Marcos André
Fonte: Universidade Federal do Paraná Publicador: Universidade Federal do Paraná
Tipo: Dissertação Formato: 90 f. : il. algumas color., tabs.; application/pdf
PORTUGUêS
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Orientadora : Profª. Drª. Juliana Quadros; Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Zoologia. Defesa: Curitiba, 26/02/2015; Inclui referências; Area de concentração: Zoologia; Resumo: A Lontra Neotropical, Lontra longicaudis, é um mustelídeo semiaquático que no passado foi alvo de caça devido a sua pele. Hoje em dia, outros fatores de origem antrópica afetam a conservação desta espécie cuja população atualmente está em declínio. Estudos com impacto de desastres naturais sobre a fauna são muito raros na literatura científica. Considerando as lontras, informações publicadas não foram encontradas. Então, o presente estudo objetivou determinar se os deslizamentos de terra ocorridos em março de 2011 em parte das montanhas da Serra da Prata (Estado do Paraná, Brasil) afetaram de alguma forma a ocorrência e a dieta da Lontra Neotropical. Com esse propósito, a área estudada compreendeu um rio afetado (Rio Santa Cruz - RSC) da face leste dessa serra que foi comparado com outro não afetado (Rio das Pombas - RP), localizado na mesma face e com características semelhantes às originais do RSC. A área de estudo está situada no Parque Nacional de Saint-Hilaire/Lange (PNSHL). Foram realizadas sete campanhas a partir do limite altitudinal do PNSHL (60m s.n.m) para montante e uma no sentido oposto em direção à planície costeira entre 2012 e 2013...

Effects of the flood regime on the body condition of fish of different trophic guilds in the Upper Paraná River floodplain, Brazil

Abujanra,F.; Agostinho,AA.; Hahn,NS.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
Relevância na Pesquisa
46.4%
In this study, we evaluated the influence of various hydrological cycles on the feeding body condition of fish species of different trophic guilds in the Paraná River floodplain, as well as the impacts of upstream impoundments on fish conditions. Attributes of the river floods (duration, time of year, intensity, and variability in a given year) and the body condition, measured by the mean residuals of length-weight ratios, of the detritivorous, herbivorous, insectivorous, invertivores, omnivorous, piscivorous, and planktivorous species were evaluated. Fish were sampled during a period before (1986-1994) and after (2000-2004) the completion of filling of the Porto Primavera Reservoir, which is located upstream from the floodplain area under study. Three sub-basins in the floodplain were sampled: the Ivinheima River, which has no dams; the Paraná River, which has several dams; and the Baia River, which is influenced by the Paraná. A two-way ANOVA identified significant variations in mean body conditions for localities and for the hydrological cycles, and the interactions were also significant. The findings revealed that before the Porto Primavera Reservoir was filled, the body condition of the feeding guilds varied similarly in the three sub basins...

Exotic species of zooplankton in the Upper Paraná River floodplain, Daphnia lumholtzi Sars, 1885 (Crustacea: Branchiopoda)

Simões,NR.; Robertson,BA.; Lansac-Tôha,FA.; Takahashi,EM.; Bonecker,CC.; Velho,LFM.; Joko,CY.
Fonte: Instituto Internacional de Ecologia Publicador: Instituto Internacional de Ecologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
Relevância na Pesquisa
46.18%
The integrity of aquatic ecosystems is being challenged worldwide by invading species, which has been one of the frequent causes of biodiversity loss. The invader may cause extinctions of vulnerable native species through predation, grazing, competition and habitat alteration. Daphnia lumholtzi G. O. Sars, 1885, a native cladoceran from Australia, Southwestern Asia and North Africa, has recently been found in the Neotropical region. The D. lumholtzi records from the Upper Paraná River floodplain were restricted to the Pombas floodplain lake (22º 47' 55.92" S and 53º 21' 32.58" W) and Pau Véio Backwater (22º 44' 50.76" S and 53º 15' 11.16" W), in 2003 and 2008, respectively. This species can be distinguished from the other Daphnia species registered in Brazil by the conspicuous pointed fornix, the sizes of the tail spine and helmet, and a carapace ventral margin with strong spines. The high temperatures in the tropical region, as well as the increase in water transparency and the decrease in nutrient concentration observed in the environments of the Upper Paraná River floodplain due to the upstream retention by dams, may favor the development of D. lumholtzi populations. The development of populations of D. lumholtzi in natural environments of the Upper Paraná River floodplain may suggest that this species is establishing in the Neotropical region.

Longitudinal distribution of Chironomidae (Diptera) downstream from a dam in a neotropical river; Distribuição longitudinal de Chironomidae (Diptera) abaixo de uma barragem em um rio neotropical

Pinha, G. D.; Aviz, D.; Lopes Filho, D. R.; Petsch, D. K.; Marchese Garello, Mercedes Rosa; Takeda, A. M.
Fonte: Instituto Internacional de Ecologia. Publicador: Instituto Internacional de Ecologia.
Tipo: info:eu-repo/semantics/article; info:ar-repo/semantics/artículo; info:eu-repo/semantics/publishedVersion Formato: application/pdf
ENG
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56.23%
The damming of a river causes dangerous consequences on structure of the environment downstream of the dam, modifying the sediment composition, which impose major adjustments in longitudinal distribution of benthic community. The construction of Engenheiro Sérgio Motta Dam in the Upper Paraná River has caused impacts on the aquatic communities, which are not yet fully known. This work aimed to provide more information about the effects of this impoundment on the structure of Chironomidae larvae assemblage. The analysis of data of physical and chemical variables in relation to biological data of 8 longitudinal sections in the Upper Paraná River showed that composition of Chironomidae larvae of stations near Engenheiro Sérgio Motta Dam differed of the other stations (farther of the Dam) The predominance of coarse sediments at stations upstream and finer sediments further downstream affected the choice of habitat by different morphotypes of Chironomidae and it caused a change in the structure of this assemblage in the longitudinal stretch.; O barramento de um rio pode causar graves consequências sobre a natureza do ambiente, abaixo da barragem, modificando a composição do sedimento, as quais impõem importantes ajustes da distribuição longitudinal das comunidades bentônicas. A construção da Usina Hidrelétrica Engenheiro Sérgio Motta no alto rio Paraná...

Morphodynamics in the Confluence of large regulated Rivers: the case of Paraná and Paranapanema Rivers

Stevaux,José C.; Paes,Renato J.; Franco,André Amâncio; Etchebehere,Mário L. de C.; Harumi Fujita,Rafaela
Fonte: Latin American journal of sedimentology and basin analysis Publicador: Latin American journal of sedimentology and basin analysis
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
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The confluence of the Paraná and Paranapanema Rivers is studied according to morphology and dynamics. It is probably the only example of this type of fluvial environment involving a large, tropical and intensive regulated river. Confluence channels were monitored along a hydrological cycle (high-low water level) in terms of morphology, flow velocity, magnitude, structure, and bedload dynamics. In this case, hydrology is controlled by the flow of the tributary, which develops a continuous and well-defined thalweg since the collector channel (a secondary channel of the Paraná River) that presents relatively large bedforms that reduce stream power by increasing roughness. Although significant differences in channel morphology were not observed along the hydrological year, bed material texture indicates that the channel bottom is suffering a slight armoring process. This is probably the reason for the large asymmetry of channel confluence where the depth of the tributary channel is larger than that of the main collector channel (the Paraná left branch). The Rosana Dam, closed in 1987 and located 26 km upstream from the confluence, is the cause of the changes in sediment transport and the generation of the channel pavement. With the closing of the Porto Primavera Dam (2000) in the Paraná River (27 km upstream from the confluence) a new morphodynamics is foreseen for this environment...

Effects of bridge construction on the benthic invertebrates structure in the Paraná River Delta

Blettler,Martin C. M; Marchese,Mercedes R
Fonte: ASOCIACIÓN INTERCIENCIA Publicador: ASOCIACIÓN INTERCIENCIA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2005 EN
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Benthic assessment of lotic environments affected by bridge and highway construction at the Paraná River Delta is reported. The purpose of the study was to examine the degree of impact of physical disturbances on benthic invertebrates in four secondary channels, Carbón Chico, Carbón Grande 1, Carbón Grande 2 and Paranacito Victoria rivers. Cluster and DCA analyses showed two groups of habitats based on the grain size sediments and organic matter content. The sites with silt-clayed sediments, mainly upstream from the bridges, showed higher species richness, diversity and benthic biomass than the sites with sandy sediments, under and downstream from the bridges, where the highest densities reached by Narapa bonettoi and Myoretronectes paranaensis were observed. Although the bridge construction has affected the benthic structure due to the erosion process of bottom sediments, the typical r-strategist species assemblage related to sandy unstable sediments in the Paraná River colonized the habitat successfully within less than one year from the disturbances.